Anatomy, Physiology, Biochemistry Flashcards

Question

V3 Mandibular nerve divisions

Answer 1

1) Trunk branches 2) Anterior branches 3) Posterior branches

Answer 2

Meningeal nerve | Nerve to medial pterygoid

Answer 3

Masseteric Deep temporal Buccal Nerve to lateral pterygoid

Answer 4

Auriculotemporal Inferior alveolar Lingual

Answer 5

``` Temporal Zygomatic Buccal Mandibular Cervical ```

Answer 6

Conus medullaris (around vertebrae L1 and L2)

Answer 7

Anterior spinal artery Posterior spinal arteries *2 Radicular artery Segmental medullary artery

Answer 8

Spinal cord level T1 to L2

Answer 9

1) allow passage of all ascending and descending pathways 2) contains many cranial nerve nuclei 3) contains reticular formation, which control essential life functions e.g heart beat, breathing, BP

Answer 10

Fiber tracts nuclei of CN V, IX-XII Pyramid: anterior surface, descending nerve tract, decussation inferiorly Olives: protrude from anterior surface; olivary nuclei help regulate balance, modulation of inner ear sound Reticular formation (reticular nuclei - flexor) Vestibular nuclei

Answer 11

Fiber tracts Pontine nuclei: anterior portion, relay between cerebrum and cerebellum Nuclei for CN V - IX; posterior portion Reticular formation (reticular nucleus - extensor) Sleep centre Respiratory centre

Answer 12

1) autonomic regulation of vital organ system e.g heart beat, breathing 2) behaviour control 3) somatic motor activities 4) sleep cycle and alertness (ARAS) 6) pain modulation

Answer 13

Tracts: - tegmentum - corticospinal tract via cerebral peduncle Nuclei: - tectum aka corpora quadrigemina: 4 nuclei on dorsal surface; superior and inferior colliculi - superior colliculi: visual reflex - inferior colliculi: hearing - red nucleus: rubrospinal tract (UL flexor) - substantial nigra: connect with basal nuclei of cerebrum - CN III - V

Answer 14

1) locus ceruleus-norepinephrine system 2) raphe nucleus-serotonin system 3) pontine-acetylcholine system 4) substantia nigra-dopamine system

Answer 15

Major relay for all ascending sensory information except olfaction Controls touch, temperature, pressure perception Movement control

Answer 16

Epithalamion Thalamus Subthalamus Hypothalamus

Answer 17

Pineal gland secretes melatonin

Answer 18

Connects subthalamic nuclei and basal ganglia --> control movement and emotion

Answer 19

``` TAN HATS thirst and osmoregulation Adenohypophysis Neurohypophysis (ADH, oxytocin) Hunger Autonomic regulation Thermoregulation Sex ```

Answer 20

VA (GP -> prefrontal) VL (motor; BG -> sup MCor) VPM (face sensation & taste; trigeminal and gustatory -> S1) VPL (pain, temp, touch, pressure, proprio; spinothalamic trc & DC/ML -> S1) LGN (vision; CN II -> visual cortex) MGN (hearing; superior olive and inferior colliculi -> auditory cortex)

Answer 21

Inferior frontal gyrus, dominant lobe Assembles motor programs of speech and writing Non-fluent aphasia Intact comprehension Area 44

Answer 22

1) arcuate fasciculi (gyri within a lobe) | 2) longitudinal fasciculi (frontal lobe with other lobes)

Answer 23

Superior temporal gyrus analysis and formulation of language content Fluent aphasia Non-comprehensible Area 22

Answer 24

Pachymeninx - Dura mater (periosteal, meningeal) Leptomeninx - arachnoid mater - pia mater

Answer 25

1) molecular layer 2) external granular layer 3) external pyramidal layer 4) internal granular layer 5) internal pyramidal layer 6) multiform layer

Answer 26

1) pia mater invagination in ventricles 2) ependymal cells 3) blood capillaries

Answer 27

More Na Cl and H ions than plasma Less Ca K ions, glucose and protein than plasma

Answer 28

Nourish the brain Fluid cushion to protect Reduce brain weight by 97%

Answer 29

Anterior cerebral - anteromedial surface Middle cerebral - lateral surface Posterior cerebral - posterior and inferior surface

Answer 30

``` Purkinje cells (GABA; dual input; direct from cf; indirect from mf; only cortical output neuron) Granule cells (excitatory neurotransmitter; receive mf) Golgi cells (GABA) Basket cells (GABA) Stellate cells (GABA) ```

Answer 31

``` Cingulate gyrus Mammillary body Amygdala Fornix Hippocampus ```

Answer 32

Spinothalamic (anterolateral) pathway Dorsal column-medial lemniscus pathway Spinocerebellar pathway

Answer 33

Touch, pressure (anterior tract) Pain, temperature (posterior tract)

Answer 34

Discriminative touch and proprioceptive information

Answer 35

A delta fibre, C fibre 1) ipsilateral dorsal root ganglion 2) ipsilateral substantia gelatinosa; travels through central commisure to contralateral anterior or lateral spinal cord white, where they ascend to thalamus 3) VPL nucleus of contralateral thalamus

Answer 36

A alpha, A beta, A delta fibres 1) ipsilateral posterior root ganglion, do not synapse in spinal cord but pass into dorsal column white (fasiculus cuneatus or gracilis) 2) ipsilateral nuclei gracialis or cuneatus on posterior medulla, leave medulla and cross to contralateral side before reaching thalamus 3) VPL nucleus of thalamus

Answer 37

OVALE ``` Otic ganglion V3 mandibular nerve Accessory meningeal artery Lesser petrosal nerve Emissary veins ```

Answer 38

MMM Middle meningeal artery Middle meningeal vein Meningeal branch of mandibular nerve

Answer 39

Roof: Hard palate Floor: mylohyoid muscle Side wall: buccinator muscle

Answer 40

ZIP Zygomatic branch of maxillary nerve Infraorbital vessels (inferior ophthalmic vein) Pterygopalatine ganglion's ascending branches

Answer 41

1) from maxilla 2) from pterygomaxillary ligament (from maxillary tuberosity to hamulus of medial pterygoid plate) 3) pterygomandibular raphe (interdigitates with superior constrictor of pharynx; ends just superior end of mylohyoid line 4) external oblique line of mandible up to first molar

Answer 42

Palatoglossal arch - aka anterior pillar of fauces

Answer 43

Below the skull and extends down to the level of soft palate (C1)

Answer 44

C1 (soft palate) to C3 (epiglottis)

Answer 45

C3 (epiglottis) to C6 (cricoid cartilage)

Answer 46

Respiratory epithelium

Answer 47

Stratified squamous epithelium

Answer 48

Stratified squamous epithelium

Answer 49

Tensor veli palatini (V3 nerve to medial pterygoid) Levator veli palatini (pharyngeal plexus) Palatopharyngeus (pharyngeal plexus) Palatoglosus (pharyngeal plexus) Musculus uvulae (pharyngeal plexus)

Answer 50

Source: CN IX, CN X, CN XI, sympathetic branches from superior cervical ganglion Sensory: CN IX Motor: CN XI via CN X

Answer 51

1 Cricoid cartilage (hyaline) 1 thyroid cartilage (hyaline) 1 epiglottic cartilage (yellow) 2 arytenoid cartilages (hyaline)

Answer 52

Circular: 1) superior constrictor [ph plx] 2) middle constrictor (thyropharyngeus [ph plx] and cricopharyngeus [CN X]) 3) inferior constrictor [ph plx] Longitudinal: 1) salpingopharyngeus [ph plx] 2) palatopharyngeus [ph plx] 3) stylopharyngeus [CN IX]

Answer 53

Thyrohyoid membrane Cricothyroid membrane Quandrangular membrane

Answer 54

``` Elevation: Digastric Stylohyoid Mylohyoid Geniohyoid Stylopharyngeus Salpingopharyngeus Palatopharyngeus ``` Depression: Sternothyroid Sternohyoid Omohyoid

Answer 55

1) aryepiglottic 2) oblique arytenoids 3) thyroepiglottic 4) posterior cricoarytenoid 5) lateral cricoarytenoid 6) transverse arytenoids 7) cricothyroid 8) thyroarytenoid 9) Vocalis

Answer 56

V2, V3 Roof: greater palatine; nasopalatine Floor: lingual Cheek: buccal

Answer 57

Palatine process of maxilla Horizontal plate of palatine bone Premaxilla

Answer 58

Greater palatine artery Anterior palatine nerve (Between maxilla and palatine bone)

Answer 59

Perforated palatine bone Middle and posterior palatine nerves

Answer 60

Greater palatine artery pass up to nasal cavity Anterior palatine nerve pass up Nasopalatine nerve pass down

Answer 61

Superior longitudinal fibres Inferior longitudinal fibres (along genioglossus, medial to hyoglossus) Transverse fibres Vertical fibres ACTION: change tongue shape: - transverse: narrow and heap up dorsal into convexity - transverse + vertical: narrow but dorsum convexity flattened, thus smaller cross section and elongate - trans+vert+ genioglossus: protrusion

Answer 62

Change tongue position: Genioglossus XII -> protrusion Hyoglossus XII -> draw sides down Palatoglossus (phary plx) -> raise for swallowing Styloglossus XII -> retract for swallowing

Answer 63

Ranine vein -> underside to common facial vein Lingual vein -> internal jugular vein

Answer 64

Anterior 2/3 - sense: lingual - taste: chorda tympani - secretonotor: C T Posterior 1/3 - sense: IX - taste: IX - secretomotor: IX Motor XII except palatoglossus (pharyngeal plexus)

Answer 65

1) fluid lubricant 2) ion reservoir/ remineralisation 3) buffer 4) cleansing 5) anti microbial 6) agglutination 7) pellicle formation 8) digestion 9) taste 10) excretion 11) water balance

Answer 66

Chewing Vomiting Taste (esp sour) Food

Answer 67

1) vascular - sympathetic vasoconstriction -> decrease filtration pressure thus scanty secretion - parasympathetic vasodilation -> increase filtration pressure thus copious secretion 2) myoepithelial cell - Sympathetic constriction (alpha adrenoceptor -> expulsion of saliva) - Parasympathetic constriction (muscarinic Ach receptor -> expulsion of saliva) 3) Secretory cell - sympathetic (beta adrenoceptor) -> protein release and scanty viscous secretion - parasympathetic (muscarinic Ach receptor -> electrolyte transport and copious watery secretion

Answer 68

1) Gland of secretion (at rest 65% submandibular 20% parotid; high flow rate 50% parotid) 2) Duration 3) Circadian rhythm (Na Cl peak in morning, K peak 12 hrs out of phase, Protein peak in late afternoon) 4) Flow rate (high flow rate -> more Na Cl HCO3, pH) 5) Nature of stimuli -> affects flow rate

Answer 69

1) vascular - sympathetic vasoconstriction (alpha adrenoceptor) -> decrease filtration pressure thus scanty secretion - parasympathetic vasodilation (Ach muscarinic receptor or VIP receptor) -> increase filtration pressure thus copious secretion [NOTE: 1) Increase capillary blood flow, increase capillary hydrostatic pressure, increase fluid supply to acinar cells; 2) Increase Arteriovenous anastomotic blood flow, increase venous hydrostatic pressure, increase filtration pressure via back transmission on high venous pressure, increase fluid supply to acinar cells] 2) myoepithelial cell - Sympathetic constriction (alpha adrenoceptor -> increase intraductal pressure -> expulsion of saliva) - Parasympathetic constriction (muscarinic Ach receptor -> increase intraductal pressure -> expulsion of saliva) 3) Secretory cell - sympathetic (beta adrenoceptor) -> protein release and scanty viscous secretion - parasympathetic (muscarinic Ach receptor -> electrolyte transport and copious watery secretion

Answer 70

Frontonasal, ethmoidal and sphenoidal bones

Answer 71

Nasal bones Nasal part of frontal bone Frontal process of maxilla

Answer 72

Palatine process of maxilla Horizontal plate of palatine bone

Answer 73

``` Clonal deletion Clinal anergy Activation induced self death Sequestration antigen Treg cells (CD4 cd25 foxp3) release TGFbeta IL10 ```

Answer 74

CD3 CD4 CD25 foxp3 Releases TGF beta and IL 10 - Inhibit potentially harmful immune responses - prevent autoimmune responses and allograft rejection

Answer 75

Precursor of Th1 and Th2 Releases IL2,4,5,6,10,13 IFN gamma and TNF

Answer 76

Th0, Th1, Th2 All expresses CD3 and CD4

Answer 77

CD3 CD4 Induced by IL12 (produced by APC) by induction of IFN gamma Inhibited by IL4 IL10 IL13 Secretes IL2 (autocrine), IFN gamma, TNF alpha Activates macrophages CMI

Answer 78

Lymphatic capillaries Lymphatic vessels Lymphatic nodes Lymphatic trunks Lymphatic ducts Lymphatic tissues

Answer 79

CD3 CD4 Induced by IL4 Inhibited by IFN gamma Secretes IL4, IL5 IL6 IL10 IL13 Recruits eosinophil Promote B cells IgE production Humoral immunity

Answer 80

Jugular Subclavian Bronchomediastinal Intestinal Lumbar

Answer 81

Right lymphatic duct (drains right side of head, right upper limb, right thorax) Thoracic duct

Answer 82

``` NK cell B cell -> plasma cell T cell Macrophage Dendritic cell Reticular cell ```

Answer 83

Throughout the body under moist epithelial membrane ie gastrointestinal, respiratory, genitourinary tracts (eg Peyer's patches in ileum) MALT GALT BALT

Answer 84

Superior mediastinum; posterior to sternum and anterior to heart great vessels

Answer 85

Pharyngeal (roof of pharynx; respiratory epithelium)) Palatine (between palatoglossus and palatopharyngeus arches; stratified squamous) Lingual (base of tongue, stratified squamous; not as deep tonsillar crypts)

Answer 86

Thymulin Thymopoietin Thymosin alpha 1 and beta 4

Answer 87

Development of immunocompetent T lymphocytes to produce Th and Tc Proliferation of clones of mature naive T cell to supply circulating lymphocyte pool and peripheral tissues Development of immunological self tolerance Secretion of hormones and factors to regulate T cell maturation proliferation and function

Answer 88

Located in thymus - 6 types I - boundary of cortex and capsule; serve to separate thymus parenchyma from connective tissue II - within cortex; stellate with processes and desmosomes that join long cytoplasmic processes on adjacent cells; serve to compartmentise areas for developing T cell, and T cell education III - between cortex and medulla; functional barrier IV - in cortex and medulla; close to type III as barrier at corticomedullary junction V - in medulla; stellate with processes joined by desmosomes VI - thymic/ Hasall's corpuscles; flattened nuclei; produces IL4 and 7

Answer 89

No afferent lymphatic vessels bring lymph into tonsils: supply of tonsillar lymphoid cell is exclusively by blood

Answer 90

Aka thymic corpuscle, found in thymic medulla Flattened epithelioreticular cell (type VI) wrapped around each other in lamellar fashion and vary in diameter; keratinised, and joined by desmosomes and contain keratohyalin granules

Answer 91

Found in the thymic cortex: Epithelial cells form a sheath around capillaries to prevent entry of antigenic materials into spaces between epithelial cells Blood capillary endothelial cell are not fenestrated Endothelial cell basal lamina Thin perivascular connective tissue with pericytes and macrophages Type I ERCs with basement membrane --> prevent lymphocytes from premature differentiation

Answer 92

1) immature lymphocyte predominates 2) no afferent lymphatics, few efferent lymphatics 3) mature lymphocytes leave and enter blood via postcapillary venules in medulla, never recirculate here 4) blood thymus barrier 5) ERCs with few fibres in medulla 6) Hassall's corpuscle 7) no germinal centres

Answer 93

Covered by perineum Encapsulated by dense connective tissue - collagen elastic fibres and smooth muscle fibres Branching trabeculae derived from the capsule enter the spleen parenchyma Reticular fibres form spleen stroma White pulp (splenic nodules) and red pulp (splenic sinusoids) and marginal zone between white and red No cortex no medulla no afferent lymphatic vessels

Answer 94

1) splenic artery in hilum -> trabecular arteries -> central arteries (follicular arterioles) -> continues and displaces eccentrically 2a) central arteries -> periarterial lymphatic sheath PALS and penetrates lymphatic nodule/ white pulp 2b) Central arteries -> displaces eccentrically to penicillar artery, and ends as macrophage sheathed capillaries (phagocytose RBCs) 3) terminal capillary drains to splenic sinusoids (close circulation) or terminates as open-end vessels with the red pulp (red pulp) 4) splenic sinusoids -> drained by pulp veins to trabecular vein -> splenic vein

Answer 95

Thymus and bone marrow -> provide microenvironment for development and maturation of lymphocyte

Answer 96

Left superior corner of abdominal cavity

Answer 97

Spleen, lymph nodes and nodules, GALT, MALT, BALT, Peyer's patches of ileum -> provide environment for lymphocyte interaction with antigens and accessory cells

Answer 98

I.e. Splenic nodules for immune component 1) central artery leads to periarterial lymphatic sheath PALS (T cells), which follows along secondary lymphatic nodules (B cells) 2) randomly distributed among red pulp cords and sinuses 3) corona with B cells and APCs 4) Activated B cells migrate to germinal centres near central artery 5) Plasma cells migrate to red pulp and release antibody to sinuses

Answer 99

Found between red and white pulp, peripheral to periarterial lymphatic sheath PALS around central artery Receive radial arterioles from central artery Consist of loose lymphatic tissue with phagocytic macrophage and APCs Dendritic cells trap and present antigens to plasma cells This is where blood contacts the splenic parenchyma (macrophage and APCs)

Answer 100

Supported by reticular fibres - reticular cells and macrophage Splenic cords = plasma cells and Mac and blood cells supported by reticular stroma Splenic sinusoids = discontinuous vascular spaces lined by rib shaped endothelial cells oriented parallel along sinusoid long axis Ring like strands of basal lamina and reticular fibres, as well as macrophages, surround splenic sinusoids ``` Open circulation (blood vessels opening to red pulp spaces) and closed circulation (blood vessels leading to splenic sinusoids) --------- ``` Filter to remove ages and damaged RBCs and microorganisms from blood Storage site for RBCs

Answer 101

Blood------ 1) filters blood 2) remove and destroy old and abnormal RBCs; breakdown products, bilirubin and iron are transported to liver via splenic and portal veins 3) blood passes through red pulp before leaving spleen - macrophage remove foreign substances and worn out RBCs via phagocytosis Immune-------- 4) supply effector T and B cells in white pulp, which activated during infection or inflammation 5) immune response to blood borne antigen presented via APCs 6) produce antibodies via plasma cells 7) phagocytosis

Answer 102

Inguinal - from lower limb Axillary - from upper limb and chest Cervical - from head and neck

Answer 103

1) capsule of dense connective tissue 2) cortex - trabeculae - lymphatic nodules with dark corona of B cell; and germinal centre with lymphoblasts and plasmablasts - mantle zone for memory cell migration 3) paracortex (deep cortex) - T cells - HEV (for B and T cell entry) 4) medulla - mature B cells in medullary cords - cords separated by medullary sinus - plasma cells secrete Ab into efferent LVs - follicular DCs - APC 5) subcapsular sinus

Answer 104

Afferent lymphatic vessels enter cortex, the postcapillary high endothelial venules HEV enters paracortex and allow lymphocyte entry Medulla with medullary cords and sinusoids Efferent vessels at hilum ---- unidirectional flow of lymph: 1) afferent lymphatic vessels and HEV 2) subscapulr sinus 3) Trabecular sinus 4) medullary sinus 5) efferent lymphatics

Answer 105

1) defence against foreign substances and toxins 2) filter of lymphs via reticular processes that spans sinuses -> disturb and retard lymph flow to allow time for macrophage phagocytosis of antigens and debris, and allow dendritic cells or B cells to detect for antibody production 3) maintenance and production of immune effector cells

Answer 106

Primary; mostly small B cells Secondary: formed in response to antigenic challenge - follicular dendritic cells and macrophage stimulate B cells to enlarge and prepare for mitosis - proliferate and for plasma cell formation, producing antibody

Answer 107

1) structure - Encapsulated (meissner's corpuscle, pacinian corpuscle, ruffini corpuscle) - Unencapsulated (free nerve endings, hair follicle receptor, Merkel disc) 2) rate of adaptation - slowly adapting (merkel disc, ruffini corpuscle; skin indentation depth, intensity, form and texture) - moderately rapid adapting (meissner's, hair follicle; velocity, motion and flutter) - rapidly adapting (pacinian; acceleration, vibration, rapid repetitive displacement of skin) 3) modality Meissner's - touch, motion and flutter Pacinian - vibration Ruffini - skin stretch Merkel - touch, pressure and form Hair follicle - direction and velocity of movement Free nerve - temperature, pain, itch and tickle

Answer 108

1) body position (static limb position and trunk orientation) 2) movement (velocity and direction of joint movement) 3) forces generated by muscle contractions

Answer 109

1) muscle spindle (annulospiral and flower spray endings, gamma motor neuron control; sense extension - static ie muscle length and stretch - and dynamic is velocity of stretch) 2) Golgi tendon organ (sense muscle tension ie contraction) 3) joint receptor (free nerve endings and corpuscular receptors; for dynamic response; group II II IV fibres, found in connective tissues capsule and ligament of joints) 4) cutaneous mechanoceptors help

Answer 110

Romberg test Patient maintain balance while standing with feet together and eyes closed

Answer 111

Proprioceptors Labyrinth receptor in inner ear Visual input

Answer 112

I) Static temperature detection - detection constant skin temperature - cold and warmth receptors - localisation only accurate when accompanied by tactile activation - at temperature extremes adaptation won't occur II) dynamic temperature sensation - detect change in skin temperature - depends on: i) initial skin temperature (threshold for warmth and cold) ii) rate of temperature change (more rapid more easily sensed) iii) area of activated skin (spatial facilitation)

Answer 113

Central Thermoreceptors - hypothalamus and spinal cord - thermoregulation Cutaneous Thermoreceptors - cold and warmth receptors - conscious sensation of temperature - thermoregulation

Answer 114

1) motor system - as continuous sensory feedback 2) limbic system eg hippocampus - for emotion and memory 3) polysensory association cortex in temporal lobe - for creation of abstract sensory map of external world

Answer 115

the subjective perception of aversion or unpleasant sensory and emotional experience associated with actual or potential tissue damage

Answer 116

1) modalities 2) intensity coding - stimulus converted to electrochemical energy - amplitude of receptor potential and frequency of afferent fibres modulation - population coding of recruitment 3) temporal coding - duration of stimuli measured by discharge of receptors of different adapting speed (rapidly - onset and termination; slowly - duration) 4) spatial localisation - receptive field - dermatomes and sensory homunculus - somatotopic projection 5) spatial acuity -> 2 point acuity - size of receptive field - innervation density - lateral inhibition - convergence

Answer 117

the reception of signals in the CNS evoked by activation of nociceptors that provide information about tissue damage

Answer 118

A) Somatic pain i) Superficial pain (skin; initial pain vs delayed pain) ii) Deep pain (bones, joints, muscles) B) Visceral Pain (viscera eg liver, kidney stones)

Answer 119

- Non-specialised free nerve endings - high threshold - non-adapting - majority multimodal - brain lacks nociceptor - A-delta fibres or C fibres as afferent nerve fibres

Answer 120

1) A-delta fibres - finely myelinated - larger diameter than C - intense mechanical stimuli - sharp, pricking sensation - fast and first pain 2) C fibres - unmyelinated - smallest diameter - multimodal stimuli - burning sensation - slow and second pain

Answer 121

A brief painful stimuli may give rise to two separate pain sensation to certain body surface as A-delta and C fibres produce different pain sensations

Answer 122

Associated with actual or potential tissue damage: 1) Mechanical 2) Thermal 3) Electrical 4) Chemical

Answer 123

1) Direct from stimuli to nociceptors 2) Indirect via mediator release e.g. tissue damage releases damage byproducts and inflammatory cytokines that stimulate nociceptors; prostaglandin will sensitise nociception

Answer 124

A physiological process after an injury that helps healing by ensuring that contact with the injured tissue is minimised until repair is complete tissue damage -> inflammation -> prostaglandins and bradykinin sensitise nociceptors, causing primary (at stimulation site) or secondary (site remote from original injury) hyperalgesia Allodynia -> normally innocuous stimuli perceived as pain

Answer 125

Body and limbs -> A delta and C -> dorsal root ganglion -> substantia gelatinosa -> crosses ventral commissure -> ascent along Anterolateral system -> VPL of thalamus Face and head -> A delta and C -> trigeminal nerve -> trigeminal nucleus -> cross midline via trigeminothalamic system through trigeminal lemniscus -> VPM of thalamus ------------ At thalamus -> specific thalamocortical system (topographically represented) or non-specific thalamocortical system (emotional and affective aspects of pain) ------------ Cortical projection to SI (discrimination, localisation and meaningful interpretation of pain), SII somatosensory cortex , anterior cingulate gyrus, and insula (affective components of pain)

Answer 126

From body and limbs to VPL 1) Lateral spinothalamic tract - specific thalamocortical system - Specific thalamic nucleus to S1 - For localisation, and discrimination of pain 2) Spinoreticular tract - to reticular formation (ARAS) - non-specific thalamocortical system - Intralaminar thalamic nuclei, diffuse projection to cerebral cortex in relation with limbic and hypothalamus - for arousal, autonomic reflexes and emotional aspects of pain 3) Spinomesencephalic tract & spinotectal tract - to midbrain and periaqueductal gray - for affective and aversve behaviours associated with pain, initiates orienting responses, and descending pain modulation

Answer 127

1) Frontal cortex and Periventricular area -> midbrain periaqueductal gray -> nucleus raphe magnus in medulla -> superficial layers of dorsal horn 2) parallel descending system from noradrenergic locus ceruleus in upper pons -> medulla -> dorsal horn

Answer 128

Peraqueductal gray: serotonin, glutamate, opioid neuropeptides Nucleus raphe magnus: serotonergic Locus ceruleus: noradrenergic Spinal cord dorsal horn: Enkephalin

Answer 129

1) Modalities -> A delta and C afferent contribute to different nociceptive modalities (e.g. pricking vs burning) 2) Intensity Coding - stimulus converted to electrochemical energy - amplitude of receptor potential and frequency of afferent fibres modulation - population coding of recruitment - psychological factors 3) Temporal Coding - little adaptation; protective 4) spatial localisation; poor because: - low innervation density - wide receptive field - branching and convergent ascending fibres - coarse topographical representation - -> localisation aided by contribution from non-nociceptive modalities

Answer 130

Projected pain and referred pain

Answer 131

Pain is incorrectly localised when ascending pathway is stimulated unnaturally Pain sensation projected to receptive field of stimulated nerve e.g. Spinal root compression Ascending tract compression Phantom Limb

Answer 132

Excitation of visceral nociceptors sensed as originating from superficial sites Visceral pain referred to cutaneous dermatomes that share the same dorsal root (dermatomal rule) Viscerotomes arranged according to original embryonic locations - ------- e. g. myocardial infarction, angina; acute appendictitis, gall stone colic, renal colic, ureteric colic

Answer 133

1) Axon reflex -> visceral nociception branch cause antidromic activation of cutaneous branch 2) Convergence-Projection: convergence of nociceptive cutaneous and visceral receptors onto same pool of second or higher order neutrons 3) Convergence-Facilitation: excitation of visceral afferent facilitates pain stimulus transmission from superficial pathways 4) Psychological

Answer 134

1) Local reaction (triple response -> redness, swelling, warmth) 2) Reflex action - Somatic reflex (cutaneous - flexion withdrawal; visceral - overlying muscle contraction eg peritonitis guarding) - Autonomic reflexes (Sharp - increased sympathetic activities; Dull - decrease sympathetic activities, nausea) 3) Behavioural and emotional response

Answer 135

1) Phasic contraction - discrete movements - transient contraction - rhythmic repetitive contraction e.g. walking 2) Tonic contraction - stabilise joints eg postural maintenance

Answer 136

1) Reflex 2) voluntary movement 3) Autonomic/Rhythmic motor patterns

Answer 137

motor neuron + muscle fibres that it innervates

Answer 138

1) Frequency coding -> increase in frequency of firing of motor neurone allow summation of successive muscle twitches 2) population coding -> motor units recruited in fixed order from weakest to strongest

Answer 139

``` Simple Rapid Stereotyped Involuntary Protective Controlled and elicited by stimulus ```

Answer 140

Repetitive movements e.g. walking running swallowing Only the initiation and termination is voluntary; once initiated, sequence of movement is stereotyped, repetitive and automatic

Answer 141

1) Complex, goal-directed (purposeful) | 2) Learned (performance improve with practice -> greater practice will reduce needed conscious direction)

Answer 142

1) Hierarchical organization (3 level of cerebral cortex, brainstem and spinal cord) - allow lower level to generate stereotyped movements, leaving higher centres free to generate motor commands without specifying details 2) Parallel organization - permits higher centres to adjust spinal circuitry operation - allows independent control of function

Answer 143

1) Sensory input: - Somatosensory (e.g. joints, muscle spindle) - Vestibular - Visual 2) Corticocortical inputs 3) Subcortical inputs (via thalamus) - Basal ganglion - Cerebellum

Answer 144

Ventral horn contains lower motor neurons (final pathway for motor execution) Somatotopically arranged with medial innervating axial muscles and lateral innervating distal muscles Provides: i) stereotyped response e.g. stretch reflex ii) stereotyped motor coordination e.g. flexion reflex iii) Rhythmic locomotor pattern e.g. walking swimming (can function with brain disconnection)

Answer 145

1) Somatic motor neurons (extraocular muscles and tongue intrinsic muscles via CN III, IV, VI, XII) 2) Special visceral motor neurons (striated muscle that control chewing, facial expression, larynx and pharynx; via CN V, VII, IX, X, XI) 3) General visceral motor neurons (parasympathetic preganglionic neurons innervating glands, blood vessels and smooth muscles)

Answer 146

1) Lateral descending system - rubrospinal tract - terminates on dorsolateral spinal grey - control of goal-directed movements, especially arms and hands (distal body parts) 2) Medial descending system - vestibulospinal, reticulospinal and tectospinal tracts - terminate on ventromedial spinal grey - control of posture by axial and proximal muscles

Answer 147

1) provide motor innervation to head and neck 2) modulate spinal motor neuron and interneuron activities 3) controls posture by intergrating visual, vestibular with somatosensory information 4) Movement coordination and head and eyes

Answer 148

1) Highest level - generate a mental image of body and its relationship with environment 2) Middle level - tactile decisions based on memory of sensory information from past movements 3) Lowest level - sensory feedback used to maintain posture, muscle length, tension before and after each voluntary movement

Answer 149

Location: Brodmann area 4; Precentral gyrus of frontal lobe from midsaggital sulcus to lateral sulcus Input: receives input from PMA and SMA, direct projection from sensory area in parietal lobe and thalamus, indirect projection from cerebellum and basal ganglion Output: terminate directly (corticospinal tract or corticobulbar tract) or indirectly (via thalamus) on spinal cord To striatum, thalamus and pons; form elaborate neural loops through basal ganglia and cerebellum Function: main generator/initiator of projecting signal to spinal cord; discharge frequency encodes the force of movement; direction-encoding by different populations (note: fine digit control vai corticospinal tract) ~lowest stimulation threshold

Answer 150

Location: Brodmann area 6; immediately anterior to M1 Input: posterior parietal cortex (SA? for visual and somatosensory cues) Output: medial descending system to brainstem and spinal cord to control proximal and axial muscles; corticocortical projection to M1 for distal muscle control Function: Sensory guidance - proximal and axial muscles for initial phases of body and arm target orientation - distal muscle control ~ highest stimulation threshold

Answer 151

Location: Medial part of brodmann area 6; buried within the longitudinal fissure Function: planning of movement (not directly with execution), sequence of movement, programming complex movement, coordinating bilateral movement

Answer 152

1) Corticospinal tract (pyramidal tract) - from middle and medial precentral gyrus 2) Corticobulbar tract - from lateral precentral gyrus

Answer 153

Origin: Motor cortex (lateral precentral gyrus - face areas) Terminal: cranial motor nuclei (III-XII except VIII) in brainstem (all bilateral; except hypoglossal XII and lower half of facial nuclei VII which are contralateral)

Answer 154

Superior peduncle - output to midbrain - ascending thalamocortical projection Middle peduncle - input from pons - cortico-pontine-cerebellar circuit (pontine mossy fibres) Inferior peduncle - Mainly input from medulla - spinocerebellar tract (mossy fibres) - olivocerebellar tract (inferior olive - climbing fibres)

Answer 155

10 lobules I to VIII lobule divided to 3 sagittal zones IX and X are nodulus and flocculus

Answer 156

Spinocerebellum (medial) - vermal cortex (fastigial nucleus) - intermediate cortex (emboliform, globose nuclei) Cerebrocerebellum (lateral) - hemispheric cortex (dentate nucleus) Vestibulocerebellum (flocculonodulus)

Answer 157

1) Mossy fibres (major afferent, e.g. spinocerebellar tract, cortico-pontine-cerebellum circuit) - terminates at granule cells -> parallel fibres that terminates on the dendritic tree of parking cells 2) Climbing fibres (olivocerebellar tract) - from inferior olive in medulla (with source from ruber) - terminates <10 purkinje cells

Answer 158

Error-detector by comparing command signals (from cerebral cortex via cortico-pontine-cerebellar circuit) with the updated feedback of executed motor action via spinocerebellar tract --> moment to moment mistake correction 1) Medial corticonuclear zone (fastigial nucleus): control postural and voluntary movement of axial and proximal muscles via i) ventromedial descending system - vestibulospinal tract (deiters) and reticulospinal tract (ret form) ii) ascending thalamocortical projection -> act on corticospinal component of ventromedial descending system (i.e. ventral corticospinal tract) 2) Intermediate corticonuclear zone (emboliform and globose): coordinate voluntary movement of distal body parts via: i) lateral descending system - rubrospinal trdact ii) ascending thalamcortical projection -> act on corticospinal component of lateral descending system (i.e. lateral corticospinal tract)

Answer 159

1) Movement design (from association cortex) via cerebro-pontine-cerebellar tract reach dentate, are converted to movement programs and sent to premotor cortex via thalamocortical projection for subsequent execution of goal-directed voluntary movement (esp oculomotor control) 2) Cognitive processes

Answer 160

1) Control of vestibulospinal reflex (postural movement via axial motor system) - via lateral vestibulospinal tract and reticulospinal tract (ventromedial descending system) 2) Coordination of vestibule-ocular reflex - controlled by flocculus

Answer 161

in medulla oblongata Input: vestibular apparatus Output: limb and trunk muscles -> extensor Function: equilibrium and balance e.g. vestibulospinal reflexes

Answer 162

in midbraine Input: cerebral cortex and cerebellum Output: rubrospinal tract -> UL flexor

Answer 163

Medullary - flexor Pontine - extensor

Answer 164

division between frontal and parietal lobe

Answer 165

divides temporal lobe from frontal and parietal lobe

Answer 166

thalamus and other cortical region --> layer 4 (thickest in S1) --> spread to superficial and deep layers --> Layer 3 and 5 (thickest in M1) send output to other regions

Answer 167

conical cell body apical and basal dendrites Axon leaves base of cell to white matter

Answer 168

small round cell body interneurons that receive input from cortical afferent fibres synapsing in output neuron

Answer 169

- speaking and muscle movements - making plans and judgements Higher: - problem-solving - self-motivation - planning - mental tracking - abstract thinking - general motor control

Answer 170

- Somatoesthetic interpretation - understanding speech - formulate words for expression - interpretation of shape and textures Higher: - space orientation - complex movement - recognition of self and world - perception and integration of sensory data

Answer 171

- opposite visual field's visual information - correlate visual image with previous experience - integrate eye accommodation Higher: visual and related info

Answer 172

- Contralateral auditory information | - Memory of auditory and visual experiences

Answer 173

PMA and SMA S2

Answer 174

Association cortex Multimodal association - from all sensory modalities - handle complex function

Answer 175

Works closely with motor cortices - spatial coordinates of body - effective motor planning - circuitry for word formation (Broca's) - problem solving, self motivation, planning, abstract thinking, mental tracking

Answer 176

Polymodal sensory high level analysis and interpretation of signals (visual, auditory and somatosensory inputs) - memory - spatial coordinates - Language comprehension (Wernicke's) - Written words' visual processing - Naming of objects

Answer 177

Function: language, fine motor control In 99% right handed, 50% left-handed -> dominant is left hemisphere

Answer 178

``` CT fMRI PET EEG MEG ```

Answer 179

IQ -> standardised test adjusted to a ge Wechsler Adult intelligence Scale III Folstein Mini Mental Status Examination (MMSE)

Answer 180

Folstein Mini Mental Status Examination ``` Scale of 0-30: - Copying - Attention - Registration - Recall - Orientation - Language CARROL ```

Answer 181

- Decline in speed of central processing - Decline on timed task performance - Decline in recent memory retrieval - Decline in new learning - Decline in performance IQ - presbyopia - Decline in muscle bulk and strength - Gait becomes wider based, smaller steps - Poor balance - Loss of ankle jerk

Answer 182

Definition: Needs or desire that direct behaviour Sources (+/–): 1) Drives - internal states that pushes behaviour 2) Incentives - external stimuli that pulls behaviour

Answer 183

Triggers release of dopamine in striatum --> feeling "high"

Answer 184

i.e. Nucleus Accumbens - responsible for incentive motivation processes - Dopamine received from Ventral Tegmental Area (VTA)

Answer 185

Caudate and Putamen - concerned with regulation of movement and cognition - Dopamine received from substantial nigra

Answer 186

PALOVIAN CONDITIONING - Learning predictive relationships - neutral cue precedes reliably a reinforcer - an unconditioned stimulus (e.g. food) - the neutral cue acquires motivational value per se - conditioned stimulus - Anticipatory response --> Consummatory response INSTRUMENTAL CONDITIONING - learning that an action leads to delivery of reward ->reinforcing an instrumental response - -------- - Basolateral amygdala has extensive sensory cortical input that forms CS-US association - Central nucleus of amygdala critical for CS-response outcome learning - Amygdala connected to striatum and prefrontal cortex (palovian information linked with decision making system) - Ventral striatum (Nuc Ac) gives motivational drive amplified via dopamine -> promote rewarding actions - Prefrontal cortex provide info on choices and inhibitory control

Answer 187

1) Lateral pathway i) Lateral corticospinal tract ii) rubrospinal tract 2) Ventromedial pathway i) Ventral corticospinal tract ii) Reticulospinal tract iii) Vestibulospinal tract iv) Tectospinal tract

Answer 188

i) Lateral corticospinal tract ii) rubrospinal tract Motor cortex and red nucleus -> posterior limb of internal capsule -> decussate at lower medulla (pyramid) -> lateral funiculus of spinal cord -> terminates contralaterally at interneurons (small number), or lateral ventral horn's motor neurons - Innervates limbs, especially distal muscles - All terminations are unilateral and contralateral - Terminal branch gives off few collaterals

Answer 189

i) Ventral corticospinal tract ii) Reticulospinal tract iii) Vestibulospinal tract iv) Tectospinal tract Origin -> posterior limb of internal capsule -> does not decussate -> ventral funiculus of spinal cord -> terminates ipsilaterally at interneurons (many), or medial ventral horn's motor neurons -> many collaterals leading to bilateral terminations - innervates axial and proximal muscles - Many bilateral terminations - terminal branch gives off many collaterals

Answer 190

1) Component tract difference 2) Lateral funiculus vs ventral funiculus 3) Terminal branch few collaterals vs many collaterals 4) Small number interneuron termination vs many 5) Lateral ventral horn vs medial ventral horn 6) All unilateral vs many bilateral 7) Innervates distal muscles vs axial and proximal

Answer 191

midline caudal to the median tongue bud, an endodermal thickening at foramen caecum. forms a bilobed structure and migrates ventral to the laryngotracheal tube to reach its definitive position (7th week) During migration, thyroid remains connected to the tongue by the thyroglossal duct. This duct later disappears Ultimobranchial body forms the C cells/ parafollicular cells of thyroid

Answer 192

Dorsal recess of the 3rd pharyngeal pouch becomes solid by proliferation, forming the inferior parathyroid glands Dorsal recess of the 4th pharyngeal pouch becomes solid by proliferation, forming the superior parathyroid glands Migrate caudally with the thymus and and become intimately associated with the dorsal aspect of the thyroid gland

Answer 193

embedded between the posterior border and the capsule of the thyroid usually 4, but may vary from 2 to 6

Answer 194

Superior thyroid artery (from external carotid artery) Inferior thyroid artery (from thyrocervical trunk of 1st part of subclavian artery) ------- Superior and middle thyroid vein (to internal jugular veins) Inferior thyroid vein (to brachiocephalic vein or internal jugular vein)

Answer 195

Bilobed lying on either side of the trachea and the larynx Lobes connected by isthmus at level of 2nd - 4th tracheal cartilage 50% has appendix from isthmus towards hyoid cartilage Encapsulated by a tough fibrous capsule pretracheal fascia binds the gland in front and at the back of the trachea -------- Between the gland capsule and the fibrous capsule posteriorly are the parathyroid glands sternothyroid, sternohyoid muscles and cervical fascia lie in front

Answer 196

1) External laryngeal nerve (branch of the superior laryngeal nerve; supply the cricothyroid muscle) 2) Recurrent laryngeal nerve (in the tracheo-oesophageal groove posterior to the inferior thyroid artery, 50% in pretracheal fascia; supply all laryngeal muscle except cricothyroid

Answer 197

Vesicular follicles formed by follicular cells (T3 T4), which are lined with simple cuboidal to squamous epithelium (will become columnar when active) Follicular lumen filled with homogenous colloid, thyroglobulin, with many tyrosine residues (colloid will shrink when active) Light staining parafollicular cells or C cells (Calcitonin) lies between follicles or embedded within the follicle

Answer 198

two kinds of epithelial cells: 1) Principal cells - parathyroid hormone (PTH) 2) Oxyphil cells - eosinophilic cells; function unknown.

Answer 199

Adrenergic innervation from there cervical ganglia Cholinergic innervation from the vagus nerves.

Answer 200

FLAT CHAMP GG FSH LH ACTH TSH ``` CRH hCG ADH (V2) MSH PTH ``` Glucagon GHRH

Answer 201

GOAT HAG GnRH Oxytocin ADH (v1) TRH H2 Gastrin

Answer 202

VETTT CAP ``` Vit D Estrogen Testosterone T4 T3 ``` Cortisol Aldosterone Progesterone

Answer 203

PIG Prolactin GH Immunomodulin

Answer 204

inslun, IGF-1

Answer 205

Binds to thyroid follicular cells, increase cAMP level, which will stimulate: 1) thyroglobulin production 2) NI symporter 3) TH exocytosis

Answer 206

Tetraiodothyronine (T4; usually called thyroxine) Triiodothyronine (T3) Derived from the modification of tyrosine

Answer 207

Less T3 (~10%) released by thyroid gland than T4 (~90%) T3 has greater biological activity (faster onset) than T4 (slower onset) 99.5% bound to plasma proteins vs 99.95% Small pool vs large pool Mainly intracellular vs mainly circulating Short half life (fast turnover) vs long half life (slow turnover)

Answer 208

Thyroglobulin (TG) is a large polypeptide which is synthesized in ribosomes of thyroid follicle cells in response to TSH/cAMP The TG colloid is incorporated into exocytotic vesicles and extruded into follicular antrum.

Answer 209

1) Iodide trapping 2) Oxidation 3) Iodination/Organification 4) Coupling - ------ 1) iodide is taken up actively by Na-I symporter (activated by TSH/cAMP) 2) iodide is oxidized by thyroidal peroxidase to iodine in thyroglobulin 3) tyrosine residue in thyroglobulin is iodinated and forms MIT (monoiodotyrosine) & DIT (diiodotyrosine). 4) iodotyrosines (MIT & DIT) are coupled together to form T3 & T4 [MIT+DIT=T3; DIT+DIT=T4]

Answer 210

When thyroid gland is stimulated (e.g. TSH/cAMP), vigorous endocytosis of colloid occurs. Endocytotic vesicles fuse with lysosomes inside the follicular cell. T3 & T4 are hydrolyzed from the thyroglobulin and released into the circulation via exocytosis.

Answer 211

TH is lipid-soluble but insoluble in water, therefore usually associated with binding proteins in plasma: 1) Thyroid Hormone-Binding Globulin (~70%) 2) Pre-albumin (transthyretin) (~15%) 3) Albumin (~15%) 4) Free (<1%)

Answer 212

Free or albumin bound

Answer 213

Deiodination reactions in the peripheral tissues activate and inactivate TH 25% of T4 is deiodinated (outer ring, by D1 or D2) to T3 in peripheral tissues. Deiodination (inner ring, by D1 and D3) may form an equal amount of reverse T3 which has no biological activity. T3 (and rT3) may then be inactivated by further deiodination (inner ring and outer ring respectively) to form T2

Answer 214

Deiodinase type 1 (D1) located in the liver, kidney and thyroid gland. Deiodinase type 2 (D2) located in skeleton muscle, CNS, pituitary gland and placenta. Can only deiodinate outer ring. Deiodinase type 3 (D3) found in fetal tissue and placenta; also present throughout brain, except in the pituitary. Can only deiodinate inner ring.

Answer 215

1. Cells take up free TH from blood. 2. Once inside the cell, T4 is deiodinated to T3 which enters the nucleus and binds to TH receptor (TR). 3. TR with bound T3 forms a complex with another nuclear receptor called retinoid X receptor (RxR) to initiate transcription of thyroid hormone response elements (TRE) 4. TR can also complex with other coactivators or corepressors to regulation protein production.

Answer 216

BBBB 1) Bone growth and growth 2) Brain maturation and CNS effect 3) Basal metabolic rate and thermogenesis 4) Beta-adrenergic effects and enhance heart contraction 5) Biphasic Metabolism modulation 6) Permissive effect on other hormones - ------- 1) Stimulates endochondral ossification for skeletal maturation (more cartilage to bone) 1) Biphasic effect on protein by increase proteolysis increase protein production 1) Increase growth hormone secretion and its effects 1) Stimulation of cell growth directly 1) Normal response to parathormone and calcitonin 2) Critical for brain development (deficiency → permanent mental retardation) 2) Behaviour control through expression of beta-adernoceptors to potentiate response to catecholamine (increased excitability) 3) Increase N+/K+-ATPase, which increases oxidative phosphorylation and ATP production from ADP and the basal metabolic rate; heat is generated as a result 4) Direct effect by increasing the expression of contractile proteins 4) Expression of beta-adernoceptors enhances response to adrenaline/noradrenaline (sympathetic nervous system) 4) Metabolic effect of enhanced thermogenesis and oxidative phosphorylation leads to vasodilation, ↑blood vol. → ↑ venous return → ↑ cardiac output 5) Biphasic control on glucose (increase glycolysis, increase gluconeogenesis, increase glycogenesis, increase glycogenolysis, increase GI glucose absorption [hyperglycaemia] 5) Biphasic effect on protein by increase proteolysis increase protein synthesis; [increase protein; too high -> skeletal muscle proteolysis] 5) Biphasic effect on lipid, increase lipolysis and lipid synthesis; [decrease in serum cholesterol]

Answer 217

1) By inhibiting phosphodiesterase (prevents cAMP breakdown) 2) By increasing the synthesis of adenyl cyclase 3) By increasing receptors for another hormone e.g. T4 on beta-adrenoceptor.

Answer 218

1. Hypothalamic-pituitary thyroid axis: TRH -> TSH -> T3/T4 (somatostatin released by hypothalamus inhibits TSH secretion) 2. Negative feedback: circulation T3/T4 inhibit TRH & TSH secretion 3. Environmental factors: Cold, trauma, stress 4. Excessive iodide (anti-TSH): ↓ synthesis & release of TH

Answer 219

6 levels Level Ia submental Level Ib submandibular Level II upper jugular Level III mid jugular Level IV lower jugular Level V posterior triangle Level VI pretracheal Supraclavicular fossa - lower nodes of IV and V

Answer 220

Submental - lower lip - anterior oral floor - tongue tip - mandibular incisors

Answer 221

Submandibular - oral cavity - tongue - anterior nasal cavity - submandibular gland

Answer 222

Upper jugular - nasal cavity and sinuses - oral cavity - orophaynx - nasopharynx - supraglottic larynx - hypopharynx - parotid and submandibular glands

Answer 223

Mid jugular - oral cavity - oropharynx - larynx - hypopharynx

Answer 224

Lower jugular - hypopharynx - larynx - thyroid - cervical oesophagus

Answer 225

Posterior triangle - nasopharynx - oropharynx - posterior neck and scalp

Answer 226

Drainage from neck above or below clavicle Right side - infra-clavicle lesion Left side - infra-clavicle lesion of infra-diaphragmatic lesion (via thoracic duct) aka Virchow's node

Answer 227

1) An action potential reaches the presynaptic terminal 2) ions flow through gap junction changes formed by connexons and depolarise post-synaptic membrane 3) Generation of action potential

Answer 228

1) Neurotransmitter synthesised in presynaptic terminal and stored in vesicle 2) Action potential reaches presynaptic terminal 3) Presynaptic voltage gated calcium channels open to allow calcium influx 4) Calcium influx causes fusion of vesicle and membrane that allows exocytosis of neurotransmitter vesicles 5) Neurotransmitters diffuse through synaptic cleft to reach postsynaptic membrane and bind with receptor 6) Ligand-gated postsynaptic ion channel open/close 7) Generation of EPSP or IPSP 8) Retrieval of vesicular membrane from plasma membrane

Answer 229

Faster response in electrical synapse (no lag phase between presynaptic and postsynaptic)

Answer 230

- Fixed size of 0.5mV - Spontaneous in absence of stimulation - Increased frequency with depolarisation - Neurotransmitter release

Answer 231

- Higher extracellular calcium level and calcium influx will increase the probability of fusion of synaptic neurotransmitter vesicles with plasma membrane and the release of neurotransmitters (0.5mV = one unit MEPP = one vesicle) - summation of MEPP

Answer 232

SNAP receptor Form complexes to pull membranes closer together for future fusion

Answer 233

synaptobrevin

Answer 234

syntaxin and SNAP-25

Answer 235

1) Vesicle docking 2) Formation of SNARE complexes between synaptic vesicle synaptobrevin and plasma membrane SNAP-25 and syntaxin -> pull membranes closer together 3) Influxed calcium binds to synaptotagmin -> catalyse membrane fusion

Answer 236

Clathrin Dynamin (pinching off)

Answer 237

Reversibly bind to synaptic vesicles for cross-linking -> tether them to stay in reserve pool for future neurotransmitter release

Answer 238

NEM-sensitive fusion protein Vesicle and golgi membrane fusion Priming synaptic vesicles for fusion Regulate SNARE assembly

Answer 239

soluble NSF attachment protein Vesicle and golgi membrane fusion Priming synaptic vesicles for fusion Regulate SNARE assembly

Answer 240

Norepinephrine Dopamine Histamine Serotonin

Answer 241

ATP | Adenosine

Answer 242

Glutamate Glycine GABA

Answer 243

Endorphin Enkaphalin Substance P

Answer 244

Small molecule vs peptide 1) Cell body synthesise enzyme VS synthesise pre-propeptide and enzyme 2) Slow axonal transport of enzymes to axon terminal VS fast axonal transport of nascent peptide and enzyme in vesicles along microtubule tract 3) at axonal terminal, synthesis and packaging of neurotransmitter with enzyme and precursor VS enzymatic processing of nascent peptide into mature peptide 4) Release and diffusion (identical)

Answer 245

1) Nicotinic receptor - ligand-gated Na and K channel 2) Muscarinic receptor - GPCR

Answer 246

AMPA, NMDA, Kainate

Answer 247

AMPA - ligand-gated NA channel (Na influx) NMDA - Mg blocks NMDA; Na influx will displace Mg, activate channel; ligand-gated Na and Ca channel -> Ca as secondary messenger

Answer 248

A reverse potential that is more positive than action potential threshold

Answer 249

A reverse potential that is more negative than action potential threshold

Answer 250

Pentamer, ligand-gated Cl- channel

Answer 251

Occurs when several excitatory postsynaptic potential arrives at axon hillock simultaneously

Answer 252

Postsynaptic potentials created at the same synapse in rapid succession are summed

Answer 253

GABA Benzodiazepine Barbiturates Neurosteroids Ethanol

Answer 254

High frequency stimulation (e.g. via electrodes) of synapse can cause a long-lasting increased sensitivity to the stimulation aka long term potentiation

Answer 255

macrocyclic compound made up of four pyrrole subunits; carries Fe2+

Answer 256

1) Electron carrier and ATP synthesis (cytochrome) 2) Detoxification (cytochrome P450) 3) Carrier of oxygen (haemoglobin, myoglobin) 4) Decomposition of oxidative species (catalase)

Answer 257

Glycine + succinyl Co-A --> delta-aminolevulinic acid (ALA) Enzyme: ALA synthase In mitochondria

Answer 258

ALA-S1 - chromosome 3 - ubiquitously expressed - regulated by heme - low abundance, high rate of protein turnover ALA-S2 - chromosome X - expressed in erythroid cells - regulated by iron-dependent mRNA translation

Answer 259

Haemoglobin formation

Answer 260

60% - microsomal cytochrome P450 15% - catalase some for mitochondrial cytochromes

Answer 261

ALA-S1 which is regulated by heme pool Increased heme will inhibit: 1) DNA transcription to ALA-S1 mRNA 2) mRNA translation to ALA-S1 3) translocation of ALA-S1 to mitochondria 4) directly ALA-S1

Answer 262

ALA-S1 and ALA-S2 ALA-S2 mRNA translation is inhibited when Fe-transferrin level is low (e.g. when heme is high) Increased heme may also inhibit: 1) DNA transcription to ALA-S1 mRNA 2) mRNA translation to ALA-S1 3) translocation of ALA-S1 to mitochondria 4) Directly ALA-S1

Answer 263

Reticuloendothelial system of spleen: 1) Haemoglobin -> verdoglobin; Oxidation of methane bridge in porphyrin ring (heme oxygenase) 2) Cleavage of methane bridge to tetrapyrrole --> biliverdin 3) Globin is degraded by proteases while Iron returns to iron pool 4) Reduction of methane bridge --> bilirubin (biliverdin reductase) Blood: 5) Bilirubin carried by albumin from spleen to liver Liver: 6) Bilirubin conjugated with UDP-glucuronide (udp glucuronosyltransferase) -> bilirubin diglucuronide 7) Removed from liver via bile Intestine: 8) Urobilinogen -> stercobilin Kidney: 9) Urobilinogen from intestine -> urobilin

Answer 264

Synthesis in almost all cells, especially liver and erythroid tissue (RBM in adults) (not haematopoiesis site, which is erythroid tissue only)

Answer 265

1) Involved in redox reaction - oxygen uptake (haemoglobin) - redox reaction for electron transport or detoxification or oxidative species (cytochrome, CYP, catalase) - activation of oxygen (oxidase, oxygenate) - activation of nitrogen in plants (nitrogenase) 2) Essential for cell proliferation 2) Cell proliferation

Answer 266

- Bioavailability of food iron is more important than amount of iron in diet - Heme iron more easily absorbed than non-heme - mostly in form of ferric iron Fe3+

Answer 267

``` Calcium salts Phosphoprotein in egg yolk Phytates in Bran Tannates in Tea Polyphenols in vegetables ```

Answer 268

Gastroferrin (stomach glyocprotein) forms complex with ingested Ferric iron (3+) Iron crosses brush border of intestinal mucosal cells as Ferrous iron (2+) Carrier protein in mucosal cells binds to ferrous and distribute it to rest of the body

Answer 269

Transferrin (less blood iron -> increase in transferrin)

Answer 270

Ferritin: storage as mobile fraction (more blood iron -> increase in ferritin) Hemosiderin: storage as aggregate

Answer 271

- Apoferritin made up of 24 subunits forming a sphere - A core of polynuclear hydrated ferric oxide phosphate - Hold 4500 ferric ions - 8 hydrophilic channels for communication with exterior

Answer 272

- Store iron as mobile fraction | - detoxification

Answer 273

When chelatable iron level rises, IRP-1 (IRE repressor protein-1) or IRP-2? will dissociate will dissociate from ferritin mRNA at IRE (iron-response element) -> increase translation of ferritin

Answer 274

- iron transport (binds iron from donor cells and delivers it via plasma to specific receptors on recipient cells) - distribution of iron

Answer 275

Single polypeptide chain that binds two ferric ions tightly but reversibly

Answer 276

Serotransferrin Ovotransferrin Lactotransferrin

Answer 277

a glycoprotein

Answer 278

- transferrin receptor mRNA contains 5 IREs - Low iron concentration, IRP-1 will bind to IRE, which increases the ability of mRNA and protects it from degradation -> increased translation

Answer 279

- Iron deficiency stimulates liver transferrin gene | - increased storage iron gives negative feedback on transferrin synthesis

Answer 280

1) Iron is stored as ferric (3+) in ferritin and will be converted to ferrous (2+) for transfer in blood 2) Ferritin reductase will transfer iron to transferrin (ferric -> ferrous) in presence of FAD and NADH2 3) ferrous -> ferric by a ferroxidase, ceruloplasmin, in transferrin before transport 4) Ferric-transferin may bind to reticulocytes for transport

Answer 281

Ferrous + H2O2 => Ferric + OH* + OH- O2-* (superoxide) + Ferric => O2 + OH- + OH*

Answer 282

1) Anaerobic 2) Primary source of reduced NADP - for fatty acid and cholesterol synthesis 3) Supply source of pentose (ribose) - for nucleotide and nucleus acid synthesis 4) 1 G6P produce 12 NADPH and 6 CO2

Answer 283

Phase I (oxidation) - G6P to 6 phosphogluconate 6PG via G6PD - 6PG to D-ribulose 5-phosphate via 6PGD ``` Phase II (decarboxylation-isomerization) - forms D-ribose 5P and D-xylulose 5P ``` Phase III - 5,5 -> 7,3 (2 carbon shift) - 7,3 -> 6,4 (3 carbon shift) - 5,4 -> 6,3 (2 carbon shift) - forming D-fructose 6P, D-glyceraldehyde 3P

Answer 284

- Xq28 (long arm) | G6PD deficiency not caused by single mutation, large insertion or deletion; heterogenous in nature

Answer 285

- rate limiting step in pentose phosphate pathway (G6P -> 6PG) - Generate NADPH that protects RBC membrane from reactive oxidative species (NADPH reduce glutathione via glutathione reductase to form reduced glutathione, that reacts with reactive oxidative species via glutathione peroxidase)

Answer 286

A tripeptide made up of glutamate, cysteine, glycine

Answer 287

Oxidised glutathione to reduced glutathione (NADPH -> NADP); disulphide form to sulfhydryl form

Answer 288

reduce oxidative species such as peroxides by covering reduced glutathione to disulphide oxidised form

Answer 289

(mutation leads to ALS) - binds to Cu++ and Zn++ - regulate disputation of superoxide ion into hydrogen peroxide

Answer 290

From cell body to neuronal end; kinesin

Answer 291

From neuronal end back to cell body; dynein, dynactin

Answer 292

Parkin (E3 ubiquitin ligase) mutation leads to parkinson's attachment of polyubiquitin chains to protein targeted for proteasome proteolysis

Answer 293

Arginine indicates peptide bond position that require cleaving for activation

Answer 294

COOH end: serine protease NH2 end: Gamma-carboxy glutamic acid (for localising coagulation

Answer 295

Extrinsic pathway - localised in tissue adventitia - expressed in most cells except resting endothelial cells - transmembrane protein - exposed to intravascular space after vascular damage - does not require proteolytic activation

Answer 296

Extrinsic pathway - single chain zymogen - low intrinsic enzymic activity - highly active when bound to tissue factor

Answer 297

platelet-VWF adhesion (VWF binds to subendothelial surface)

Answer 298

platelet-platelet aggregation (binds to fibrinogen)

Answer 299

1) Adhesion -> binds VWF via GpIb at site of injury 2) Release reaction -> release Ca and ADP (for coagulation cascade; ADP also helps platelet to adhere on endothelial surface and GpIIb/IIIa expression on platelet surface) 3) Prostaglandin relase (TXA2 -> pro-aggregation) 4) membrane vesiculation

Answer 300

Phospholipid in plasma membrane catalysed by floppase to express greater on outer cell surface -> localised coagulation by binding to gamma-carboxy glutamic acid of coagulation factors in the presence of Ca++

Answer 301

Complex with thrombin to Activate protein C for anticoagulation

Answer 302

Activated by thrombomodulin (with thrombin) direcrly cleaves, with protein S, membrane bound factor Va and VIIIa mediate cleavage of factor Va to Vac, which then forms complex with Protein C and Protein S, to inactivate factor VIIIa

Answer 303

PGI2 and NO released by normal endothelial cells

Answer 304

HbF (α2γ2)

Answer 305

HbA (α2β2) HbA2 (α2δ2)

Answer 306

Chromosome 16; total of 4 genes on 2 chromosomes

Answer 307

Chromsome 11; total of 2 genes on 2 chromosomes

Answer 308

1) Recognition phase (lymphocyte recognise and bind to antigen) 2) Activation phase (proliferation and differentiation -> effector cell and memory cell) 3) Reaction phase (effector cell eliminate antigen; memory cell for immunological memory)

Answer 309

Rapid response VS slow response (esp first exposure) Invariant VS variant limited specificities VS highly selective specificity constant during response VS improve

Answer 310

1) Specificity - lymphocytes express distinct membrane receptor that distinguish different antigens 2) Diversity - gene rearrangement produce many clones that can discriminate 10^9 different antigens 3) Memory - first exposure will lead to memory cell that potentiate the secondary immune response 4) Self-regulation - immune response will wane with time after antigenic stimulation 5) Discrimination of self from non-self - self tolerance

Answer 311

1) lymphocyte express surface receptors unique for one antigen 2) Antigen will bind to cells with corresponding receptor 3) specific binding to antigen will induce proliferation/ clonal expansion 4) B cell will mature into plasma cell that produce antibodies with same specificity as surface receptor 5) Some will differentiate to memory cell with as antigenic specificity 6) Contact of lymphocyte and specific antigen during embryonic development will lead to elimination of that clone 7) Removal of antigen-soecific clones result in tolerance or non-responsiveness

Answer 312

Cells that have the capacity to self-renew and generate different progeny

Answer 313

1) Expression of CD antigen | 2) Status of immunoglobin gene

Answer 314

Cluster of differentiation (CD) refers to surface antigen expressed on membrane of leukocytes

Answer 315

1) Lymphoid stem cell (CLP) 2) Early Pro-B cell 3) Late Pro-B cell 4) Large pre-B cell 5) small pre-B cell 6) Immature B cell 7) Mature B cell

Answer 316

Change in CD (e.g. CD34 in pro-B cells) CD19, CD20, CD40 commonly used be recognise B cell lineage

Answer 317

1) Lymphoid stem cell (CLP): 2) Early Pro-B cell: => D-J rearranged (μ H chain) 3) Late Pro-B cell: => V-DJ rearranged (μ H chain) 4) Large pre-B cell: => VDJ rearranged (μ H chain) => μ H chain at cell surface as pre-B receptor 5) small pre-B cell: => VDJ rearranged (μ H chain) => V-J rearrangement (κ, λ L chain) => μ H chain at cell surface and cytoplasm 6) Immature B cell => VDJ rearranged (μ H chain) => VJ rearranged (κ, λ L chain) => IgM expressed on cell surface 7) Mature B cell => VDJ rearranged (μ H chain) => VJ rearranged (κ, λ L chain) => IgM and IgD expressed on cell surface

Answer 318

Productive Ig gene rearrangement only occur on one chromosome carrying the μ H chain locus and one of the chromosome carrying the κ or λ L chain locus. μ H chain's DJ rearrangement occur on both chromosome, but V-DJ rearrangement only on one chromosome; if H chain rearrangement is successful, then κ gene will be rearranged first -> if this fails, then λ gene will be rearranged --> ALLELIC EXCLUSION (to ensure the cell expresses Ig of a single H and L chain isotype and V region specificity

Answer 319

CD44 and c-kit on pro-B cell helps binding to hyaluronic acid and SCF on stromal cells The binding will activate tyrosine kinase and stimulate proliferation Stromal releases IL-7 (enhance survival of pre-B cells by suppressing apoptosis)

Answer 320

Unsuccessful rearrangement of Ig genes -> cell loss; only when IgM expressed on cell surface (not IgD yet) will the immature B cell undergo selection in BM Self antigen (MHC) molecules are encountered, and immature B cells that generate self-reactive Ig are eliminated (if cell bound MHC -> apoptosis; if soluble antigen -> anergy Note: further L chain Ig gene rearrangement (receptor editing) can rescue some self-reactive B cell

Answer 321

Cortex: Double negative (CD3-, CD4-, CD8-) Corticomedullary junction: Double positive (CD3+, CD4+, CD8+) Medulla: Single positive (CD3+, CD4+ or CD8+)

Answer 322

Conventional B-2 cells CD5+ B-1 cells (10%, capable of self-renewal, in body cavity)

Answer 323

Majority are α:β TCR 5% are γ:δ TCR

Answer 324

1) Positive selection - Within thymic cortex - cortical epithelial cells - self MHC present foreign peptides to TCR of double positive T cells => survival of T cells that have TCR for self MHC 2) Negative selection - Within thymic medulla - macrophage and dendritic cells - TCR that recognise self peptide-self MHC complex too well are induced to undergo apoptosis

Answer 325

1) Amino acid sequences of the V regions | 2) 3D shape of antigen-binding site

Answer 326

1) Numerous Ig genes especially V region genes (a lot of V, D, J genes for H chains and V, J genes for L chains) 2) Random recombination (V-D-J gene rearrangement of H chain and V-J rearrangement of L chain) 3) Junctional diversity (Terminal deoxynucleotidyl transferase add nucleotides to single strand DNA ends) 4) Ressortment of H and L chains 5) Somatic hypermutation (nucleotide substitution)

Answer 327

- μ H chain with surrogate L chain - signal for survival of pre-B cell - expressed on cytoplasm and surface of early and late pre-B cells

Answer 328

Productive Ig gene rearrangement only occur on one chromosome carrying the μ H chain locus and one of the chromosome carrying the κ or λ L chain locus. μ H chain's DJ rearrangement occur on both chromosome, but V-DJ rearrangement only on one chromosome; if H chain rearrangement is successful, then κ gene will be rearranged first -> if this fails, then λ gene will be rearranged --> ALLELIC EXCLUSION (to ensure the cell expresses Ig of a single H and L chain isotype and V region specificity

Answer 329

Two heavy chains (linked by disulphide bond) Two light chains Fab Fc ``` V region (variable) C region (constant) ```

Answer 330

3 hypervariable regions aka complementary determining region (CDR) - HV1 to HV3 - forms hyper variable loops ``` Framework region (FR) shows less variability - beta sheets that provide the structural framework ```

Answer 331

1) RAG-1 & RAG-2 (recombination-activating gene) => initiate Ig recombination - forms a loop 2) DNA-PK, DNA Ligase => DNA cutting and rejoining

Answer 332

``` IgG IgM IgD IgA IgE ```

Answer 333

Scarce in serum, found on surface membrane of basophils and mast cells - mediate type I hypersentivity response - antiparasitic

Answer 334

Scarce in serum, found in large quantity on surface membrane of B cells - antigen triggered lymphocyte differentiation

Answer 335

20% of serum Ig, predominant in sermucous secretion like saliva, colostrum, UG secretion, milk Mainly as monomer in serum, but sometimes dimer or trimer with J-chain peptide Secretory IgA - dimer or tetramer, with J chain peptide and secretory component (polypeptide produced by mucosal epithelial cells)

Answer 336

10% of serum Ig pool Mu 2 L 2 monomer on B cell surface membrane Secreted by plasma cell as pentamer (joint by disulphide bonds) with J-chain peptide (does not diffuse well due to its large size => remain intravascular) **First Ig produced in plasma cell's primary response, and first Ig synthesised by neonates Secretory Ig

Answer 337

Major serum Ig, a lot extravascular as well Gamma 2 L2 Four subclasses: IgG1 to IgG4 major antibody for secondary response Materal IgG crosses placenta and confer passive immunity to neonates

Answer 338

1) Time course (secondary antibody response has a shorter lag phase and extended plateau and decline) 2) Antibody titre (secondary response has much greater plateau level of antibody) 3) Antibody class (IgM in primary response, IgG in secondary response) 4) Antibody affinity (antibody affinity if higher in secondary affinity)

Answer 339

At periphery (secondary) lymphoid organs: 1) Thymus dependent antigen activation (usu protein) 2) Thymus independent antigen activation - TI antigen type 1 (bacterial cell wall structure e.g. lipopolysaccharides) - TI antigen type 2 (highly repetitive molecules e.g. polymeric protein or bacteria cell wall polysaccharides with repeating polysaccharides)

Answer 340

- > Crosslinking of antigen to B cell membrane Ig initiate B cell activation (FIRST SIGNAL) - > stimulate intracellular secondary messenger to drive resting B cell into cell cycle for proliferation (increased intracellular Ca++ and PK activation) - > protein antigen is internalised and processed, then presented to antigen-specific T helper cell for activation of Th; moreover B cell will also increase expression of membrane receptor for Th cell cytokines and MHC II, to allow greater response of B cell to T cell (SECOND SIGNAL -> CD40/CD40L)

Answer 341

2 signals 1) TD antigen crosslinking membrane Ig 2) CD40 on B cell interacting with CD40L on activated T helper cell

Answer 342

- weaker in general - no memory cells generated - IgM predominant

Answer 343

1) Lag phase (clonal selection, clonal expansion, differentiation) 2) Log phase (cell proliferation, plasma cell secretion increases antibody level) 3) Plateau phase (cell proliferation, plasma cell secretion increases antibody level) 4) Decline phase (lymphocyte apoptosis)

Answer 344

- Memory B cell population is greater than population of corresponding naive B cell - Memory B cells more easily activated

Answer 345

1) Affinity maturation - higher antibody affinity in secondary response due to (IgM->IgG) switching, and SOMATIC HYPERMUTATION that recombines Ig genes 2) Class switching - allow antibody isotypes with same V domain to associate with constant region of any isotypes for different biological effector functions - membrane CD40/CD40L interaction induce class switching - T cell cytokines determine which new isotype by cytokine-dependent transcription of constant region DNA 3) B cell maturation - rapid proliferation and hypermutation of B cells after antigen stimulation - only B cell with high affinity BCR (BCL-2 gene) can compete effectively for antigen presented by follicular DC (low affinity B cell apoptosis)

Answer 346

Heterodimer, conventionally alpha and beta chain (5% is gamma and delta chain) Contains a V domain with CDRs (analogue to Vab of antibody)

Answer 347

1) Variable genes (V,D,J) 2) Gene recombination 3) Junctional diversity (TdT) 4) *** D segment read in 3 frames

Answer 348

1) TCR: antigen receptor 2) Co-receptor (CD4 or CD8) 3) CD3 as signalling complex for intracellular signal transduction upon antigen binding

Answer 349

MHC Class I alpha (3 loops) with beta 2 microglobin MHC Class II alpha (2 loops) with beta (2 loops)

Answer 350

MHC Class II

Answer 351

Chromosome 6, co-dominantly expressed (can express 6 class I, 6-8 class II) MHC Class I: Polymorphic gene for alpha chain e.g. HLA-A, HLA-B, HLA-C MHC Class II: multiple genes for alpha and beta e.g. HLA-DR, HLA-DQ, HLA-DP

Answer 352

1) Cytosolic pathway (MHC class I) 2) Endocytic pathway (MHC class II) 3) Cross-presentation

Answer 353

In MHC Class I, presents Endogenous antigens e.g. intracellular bacteria, virus, self-protein 1) Protein digested by proteasome -> peptides 2) Peptides transport via TAP (Transporter associated with Antigen Processing) to ER and loaded onto MHC class I 3) MHC-I/peptide complex translocated by golgi to cell surface for presentation to CD8 T cells

Answer 354

In MHC Class II, presents exogenous antigens e.g. extracellular microbes and protein 1) antigen taken up by endocytosis or phagocytosis -> trapped in endolytic vesicles -> fuse with lysosome -> lysosomal proteolytic enzyme degrade protein -> peptides 2) Biosynthesis of MHC II, transport via golgi to MHC II vesicles 3) Fusion of MHC II vesicle and endolysosomes -> loading of peptide to MHC II -> MHC II/peptide translocated to cell surface for presentation to CD4 T cell

Answer 355

Exogenous antigen can be cross-presented in MHC class I, by specialised APC - dendritic cells

Answer 356

All nucleated cells (therefore not in RBC)

Answer 357

APCs (e.g. B cell, macrophage, dendritic cells, thymus epithelial cells)

Answer 358

1) Capture antigen and migrate to appropriate site for T cell interaction 2) Display antigen in form recognisable by specific T cells 3) Provide second signal in naive T cell activation

Answer 359

1) Cell-mediated cytotoxicity (NK cells, Tc cells) 2) Chemotaxis and phagocytosis (macrophage) 3) Cytokine-mediated direct target cell killing (TH1 cell)

Answer 360

1) Cytotoxic T lymphocyte-mediated killing 2) Antibody-dependent cell-mediated cytotoxicity 3) Natural Killer cell-mediated killing

Answer 361

1) APC/virus infected cell/tumour cell present antigen via MHC I, which is detected by CD8 of Tc cells, CD3 of Tc cell react with MHC I 2) Co-stimulatory signal between Tc cell's CD28 and CD80/86 of APC (IL-2 from Th1 cells help activation) 3) Tc cell activation and degranulation, release of granular cytotoxic substance e.g. granzymes and perforins; also release IFN-gamma that activates macrophage 4) Osmotic lysis or apoptosis of target cell

Answer 362

by LGL Large granular lymphocytes 1) LGL have Fc receptor that binds to Fc of Ig for antigen specificity 2) Fc receptor on LGL recognise abnormal Ig on cell surface 3) Release of cytotoxic factors to kill target cell

Answer 363

No antigen specificity 1) Normal MHC I interacts with KIR (killer inhibitory receptor) while cell surface carbohydrate interacts with KAR (Killer activator receptor) 2) In tumour cells or graft cells, there is no self MHC I to interact with KIR, therefore inhibition loss and release of cytotoxic factors 3) In virus infected cells, foreign cell surface antigen activate KAR-> release of cytotoxic factors

Answer 364

Release from cytoplasmic granules Forms pores on target cell membrane -> allow granzymes to enter target cell, as well as water entry that cause osmotic lysis

Answer 365

- Enter cell via perforin - Protein that activate apoptosis - toxic to intracellular pathogen

Answer 366

1) Fc receptor-mediated (Fc receptor on phagocyte interact with antibody bound to pathogen) 2) Complement receptor mediated (C1q, C3b receptor on macrophage interact with complement deposited on pathogens via classical, alternative, or lectin-induced pathways) 3) Mannose receptor-mediated (recognise mannose and fucose oligosaccharides on pathogens)

Answer 367

1) Bacterial component (e.g. fMLP) 2) Complement products (e.g. C5a) 3) Locally released chemokines and cytokines

Answer 368

1) T-independent (chemotaxis, activation and phagocytosis, phagolysosome, killing and digestion, release of degradation products) 2) T dependent - macrophage primed with inactivated pathogen - macrophage CD40 interact with Th1 CD40L and MHC II/CD4 - Th1 release IL2 (autocrine) and IFN gamma (that activates macrophage) - macrophage activated to increase lysosome formation, phagolysosom fusion, increase translation of inducible NO synthase (iNOS)

Answer 369

1) Reactive oxygen intermediates - superoxide ions (via myeloperoxidase) 2) Reactive nitrogen intermediates (via iNOS) - Nitric oxide 3) Other mediators - complements - lysozyme - chemokines - cytokines - defensins

Answer 370

1) glucose enter Beta cells via GLUT2 2) glucokinase in cell perform oxidative phosphorylation -> more ATP 3) ATP blocks K channels, reducing K efflux causing depolarisation of membrane 4) depolarisation activates Ca channels -> Ca influx 5) increased intercellular calcium leads to exocytosis of insulin

Answer 371

Alpha adrenoceptors suppress lipolysis Beta adrenoceptors stimulates lipolysis

Answer 372

Deep-lying structures for the neural circuit involved in the expression of emotions Cingulate gyrus --> hippocampus --> mammillary body of hypothalamus --> via mammillothalamic tract --> anterior nucleus of thalamus --> cingulate gyrus

Answer 373

Phylogenetic (neocortex not available until reptile) Cortical area increase with mammalian evolution Neocortex got 6 histology layer while allocortex (e.g. hippocampus) got 3

Answer 374

bridge the communication between hippocampus and neocortex

Answer 375

oxytocin release

Answer 376

bladder contraction, decreased heart rate

Answer 377

vasopressin, oxytocin release

Answer 378

body temperature regulation, panting, sweating

Answer 379

increased blood pressure, pupillary dilation, shivering

Answer 380

Satiety center If lesion, then eat excessively (loss of satiety) and tummy grow ventrally

Answer 381

Hunger center lesion cause aphagia (lack of eating) and adipsia

Answer 382

closely connected to the hypothalamus, hippocampal formation, and amygdala Stimulation of this region causes a pleasant (euphoric) sensation; The rewarding behavior is related to the mesolimbic pathway connecting with the nucleus accumbens

Answer 383

1) Physical response | 2) Conscious feeling

Answer 384

reflexive e.g. anger, fear, happiness, sadness, surprise, disgust

Answer 385

involve more cognitive processes, e.g. envy, shame etc

Answer 386

1) protect the brain 2) House and protect sense organs 3) provide a frame on which soft tissues (e.g. muscles) can act to facilitate eating, expression, breathing, speech

Answer 387

14 ``` Lacrimal bone*2 Zygomatical bone*2 Nasal bone*2 Maxilla*2 Inferior nasal concha*2 Palatine bone*2 Mandible Vomer ```

Answer 388

2nd branchial arch

Answer 389

1) Obicularis oculi - palpebral part (close eye gently) - orbital part (close eye forcefully) 2) Corrugator supercilli - draws eyebrow to midline

Answer 390

1) Nasalis - transverse (compress nostril) - alar (opens nostril) 2) Proceus - pulls eyebrows down 3) Depressor septi nasi - pulls nose down

Answer 391

1) Obicularis oris - close lip - protrudes lips

Answer 392

1) Levator labii superioris - elevates and everts upper lip 2) Levator labii superioris alaeque nasi - raise upper lips - opens nostrils 3) Zygomaticus and 4) levator anguli oris - elevate mouth corners - zygomatic minor helps to elevate upper lip

Answer 393

1) Depressor labii inferioris - depress and evert lower lip 2) Depressor anguli oris - depress mouth corner (sad) 3) Mentalis - elevate and protrude lower lip 4) Platysma?

Answer 394

1) Risorius | - retract mouth corners (grin)

Answer 395

1) Buccinator - mastication (press cheek against teeth) - resist distension (when blowing)

Answer 396

- parotid duct penetrates through opposite to 3rd molar and opens into oral cavity opposite maxillary 2nd molar - share a common attachment with superior pharyngeal constrictor at pterygomandibular raphe The 4 insertions (max, ptmax lig, ptmd rph, mnd)

Answer 397

Anterior Posterior Superior

Answer 398

1) Depressor of lip 2) Tense skin over lower face and anterior neck 3) Depress mandible (against resistance)

Answer 399

- covers the forehead - attached to skin of eyebrow - lift eyebrow and wrinkles forehead (surprise)

Answer 400

- arise from posterior aspect of skill | - tighten the scalp

Answer 401

1) Runs penpendicular to underlying facial expression muscles 2) Surgical incisions should be made parallel to RSTLs for optimal wound healing and minimal scar

Answer 402

``` V1 Supratrochlear nerve Supraorbital nerve Infratrochlear nerve External nasal nerve Lacrimal nerve ``` V2 Zygomaticofacial Zygomaticotemporal Infraorbital V3 Buccal Auriculotemporal Mental

Answer 403

Head mesenchyme - V1 1st branchial arch - V2, V3 2nd branchial arch - CN VII

Answer 404

Stylomastoid foramen -> enters and divide in parotid gland

Answer 405

Artery: 1) Mainly by external carotid artery branches - facial artery (inferior labial, superior labial, lateral nasal, angular) - superficial temporal artery (transverse facial) 2) Internal carotid artery branches - ophthalmic artery (supraorbital, supratrochlear, dorsal nasal, lacrimal, zygomaticofacial, zygomaticotemporal) 3) Maxillary artery facial branches - infraorbital - Buccal - mental

Answer 406

1) Facial vein | 2) Retromandibular vein

Answer 407

Area drained by facial vein, ophthalmic vein, infraorbital vein, deep facial vein - leads directly or indirectly (via pterygoid venous plexus) into cavernous sinus - infection enter cavernous sinus and cause thrombosis, cerebral edema and meningitis

Answer 408

Submental node, submandibular node, pre-auricular nodes and parotid nodes Drains to superficial cervical lymph nodes Drains to superior deep cervical lymph nodes

Answer 409

Skin, contains hair and sebaceous gland Connective tissue, highly vascularised Aponeurotic layer (unites with occipitofrontalis muscle) Loose connective tissue (contains emissary veins) Pericranium, the periosteum of cranial vault

Answer 410

- consists of frontal and occipital bellies of occipitofrontalis - galea aponeurotica connects the two muscles - cause forward-backward movement of scalp

Answer 411

- contains emissary veins - allow movements - provide plane of separation (scalping) and access in craniofacial surgery and neurosurgery - laceration won't cause profound bleeding until this layer Danger zone of scalp

Answer 412

Anterior to ear and vertex by trigeminal Posterior to ear and vertex by cervical spinal ``` V1 Supratrochlear nerve Supraorbital nerve Infratrochlear nerve External nasal nerve Lacrimal nerve ``` V2 Zygomaticotemporal nerve V3 Auriculotemporal nerve ``` ----- Greater auricular nv(C2,3) Lesser occipital nv(C2,3) Greater occipital nv(C2) Third occipital nv(C3) ```

Answer 413

1) Connective tissue fibres around cut vessel contract and open the artery 2) Extensive anastomoses

Answer 414

Loose connective layer - infection may result in localised abscess and enter the valvless emissary veins to travel to diploë and dural venous sinus --> osteomyelitis and dural sinus thrombosis

Answer 415

Anterior to vertex: - preauricular node - parotid node Posterior to vertex: - mastoid nodes - occipital nodes ---- Drains to superficial cervical lymph nodes and suprior deep cervical nodes

Answer 416

Ophthalmic artery - supratrochlear artery - supraorbital artery External carotid artery - superificial temporal artery - posterior auricular artery - occipital artery

Answer 417

1) Oral cavity proper: space medial or posterior to teeth | 2) Vestibule: space between teeth and cheek

Answer 418

parotid duct penetrates buccinator opposite to 3rd molar runs obliquely under mucous membrane penetrates mucous membrane and opens into oral cavity opposite maxillary 2nd molar

Answer 419

- Greater palatine artery (from maxillary artery) -> descend via greater palatine canal, emerges from greater palatine foramen -> pass around palate -> enter incisive foramen to go up nose

Answer 420

1) Anterior palatine nerve (from pterygopalatine ganglion via greater palatine canal and foramen, goes up via incisive foramen) 2) Nasopalatine nerve (from pterygopalatine ganglion, crosses nasal roof, descend on nasal septum, through incisive foramen, supplies hard palate anterior to incisive foramen)

Answer 421

1) Auricle (yellow elastic cartilage except lobule) | 2) external acoustic meatus

Answer 422

- Outer 1/3 supported by cartilage - Inner 2/3 by temporal bone - leads to tympanic membrane - isthmus is close to membrane - ceruminous glands especially in cartilaginous part - not straight

Answer 423

Mainly Auriculotemporal nerve (posterior branch of V3) (vagus and facial nerve small branches) -> may receive referred pain from lower teeth (lower tooth cavity)

Answer 424

supericial cevical lymph nodes along external jugular vein

Answer 425

Pull auricle upwards and backwards , and then use otoscope

Answer 426

- mucosa continuous with auditory tube and nasopharynx anteriorly - mucosa continuous with mastoid antrum and air cells posteriorly

Answer 427

- Conchlea anteriorly and semicircular canals posteriorly | - between the two is vestibule, above which runs internal acoustic meatus carrying CN VII and VIII

Answer 428

- Malleus, incus, stapes (lateral to medial) - synovial joints between them - Malleus is attached to umbo of tympanic membrane via its handle - Stapes attached to fenestra vestibuli

Answer 429

- Tympanic membrane | - chorda tympani passes medially to the membrane and neck of malleus

Answer 430

- Lined externally by skin and medially by mucosa - umbo is pulled towards the centre by malleus' handle - sloping downwards and inwards - Cone of light when shone because light reflects antero-inferiorly

Answer 431

- Promontory (a bulge based by basal turn of cochlea) - Tympanic plexus on promontory (CN IX's tympanic branch) - Fenestra cochleae (for pressure release) - Fenestra vestibuli (stapes attaches here) - facial nerve lies at end of internal acoustic meatus with geniculate ganglion - bony bulge to accommodate facial nerve and lateral semilunar canal

Answer 432

- Thin - carotid canal (internal carotid artery) lies anteriorly - jugular foramen (internal jugular vein) lies posterio-inferiorly - superior bulb of IJV lies inferiorly (Ear surgery should be careful because of two great vessels)

Answer 433

aka tegmen tympani - thin - middle cranial fossa with mininges and temporal lobe lies above it

Answer 434

- opens to mastoid antrum with air cells | - Pyramid, a bony spike projecting into middle ear which contains stapedius fibres

Answer 435

- an air space in petrous part of temporal bone - below posterior cranial fossa (cerebellum) - enlarged by growth of mastoid process after birth - air cells to regulate pressure and temperature

Answer 436

- Facial nerve leaves skull via stylomastoid foramen - stylomastoid foramen is superficial in birth due to no mastoid process - facial nerve easily damaged by assisted forceps delivery

Answer 437

- opens to auditory tube | - tensor tympani (turns laterally around processes cochleariformis to attach to malleus neck)

Answer 438

- Runs downloads and medially (more horizontally in children) from middle ear anterior wall to nasopharynx - Posterolateral 1/3 is bony (petrous temporal bone) - Anteromedial 2/3 is cartilage - Junction between bone and cartilage is narrowest (isthmus) - cartilage opens wide (raised mucosa - tubal eminence) to the nasopharynx (just behind base of medial pterygoid plate) - respiratory mucosa with copious mucous gland in cartilage part; thin and landless mucosa on bone

Answer 439

Tympanic plexus (supplied by tympanic branches of glosopharyngeal nerve)

Answer 440

external carotid artery branches

Answer 441

Pterygoid venous plexus

Answer 442

Parotid/preauricular or upper deep cervical lymph nodes

Answer 443

- auditory tube opens when soft palate is lifed - levator veli palatini (phgl plx), tensor veli palatini (nv to md ptgd) => pull cartilage and open tube to introduce air into middle ear

Answer 444

- Ascending pharyngeal artery | - middle meningeal artery (foramen spinosum lies lateral to auditory tube)

Answer 445

Pterygoid venous plexus

Answer 446

nasal septum which is partly boney and partly cartilaginous | i.e. penpendicular plate of ethmoid bone, Vomer, septal cartilage

Answer 447

- Superior, middle and inferior nasal conchae/ turbinates | - and the superior, middle and inferior nasal meatus below the turbinates

Answer 448

Drainage of paranasal sinuses and nasolacrimal glands

Answer 449

Pseudostratified ciliated epithelium for most part (including paranasal sinus) - roof is different as it is lined by olfactory epithelium

Answer 450

trigeminal nerve (mostly V2, a little V1) Roof -> Olfactory nerve

Answer 451

1) maxillary artery => sphenopalatine/ nasopalatine artery 2) facial artery => alar and nasal branches 3) ophthalmic artery => anterior and posterior ethmoidal artery

Answer 452

Pterygoid venous plexus facial vein infraorbital vein ophthalmic vein

Answer 453

Air filled extension of nasal cavity in frontal, ethmoid, sphenoid, and maxilla

Answer 454

For resonance of voice and drainage Frontal: Middle meatus via infundibulum Maxillary: Middle meatus via hiatus semilunaris Sphenoid: Sphenoethmoidal recess Ethmoid: Middle meatus via infundibulum (anterior); middle meatus on bulla ethmoidalis (middle); superior meatus (posterior)

Answer 455

1) Maxillary branch of trigeminal nerve (V2) 2) Maxillary artery 3) Pterygopalatine ganglion

Answer 456

Parasympathetic in nature for secretomotor to lacrimal and nasal glands: 1) Orbital branches (inferior orbital fissure) 2) Greater and lesser palatine nerves (palate, tonsil and nasal cavity) 3) Nasal branches 4) Pharyngeal branches - roof of nasopharynx 5) Nasopalatine branch - incisive foramen

Answer 457

- roof: orbit - Medial wall: palatine bone and nasal cavity - lateral wall: infratemporal fossa - Anterior: maxilla and orbit - Posterior wall: pterygoid process of sphenoid bone, middle cranial fossa via foramen rotundum

Answer 458

1) Superior laryngeal artery (for superior aspect) - branch of superior thyroid artery - passes through thyrohyoid membrane 2) Inferior laryngeal artery (for inferior aspect) - branch of inferior thyroid artery

Answer 459

1) External carotid artery branches - MAINLY ascending pharyngeal artery - Superior thyroid a rtery - Lingual artery - Facial artery - maxillary artery 2) Subclavian artery - inferior thyroid artery

Answer 460

Lie in diploe (middle spongy bone containing RBM) of skull

Answer 461

Small veins connecting dural sinuses with diploic veins and veins of scalp Valve-less

Answer 462

No lymphatic vessels or nodes in CNS!!

Answer 463

Superficial lymph nodes drains to superficial cervical nodes along EJV and drains to deep cervical nodes along IJV

Answer 464

Forms a ring at base of head: - occipital - preauricular (parotid) - postauricular (mastoid) - Subamndibular - Submental

Answer 465

Along EJV, on superficial surface of SCM - receive from posterior and posterolateral scalp - drains to deep cervical nodes

Answer 466

Along IJV, divided by intermediate tendon of omohyoid into upper and lower groups Upper: Jugulo-digastric node Lower: Jugulo-omohyoid node

Answer 467

7 ``` Lacrimal Frontal Zygomatic Maxilla Palatine Ethmoid Sphenoid (greater and lesser wing) ```

Answer 468

Houses optic nerve | Located in lesser wing of sphenoid bone

Answer 469

``` Intraconal space Extraconal space Pre-septal space Medial anterior orbit Lateral anterior orbit Deep orbital space ```

Answer 470

All extraocular muscles insert posteriorly to annulus of Zinn (Spiral of Tillaux ie progressively distal to iris: medial rectus, inferior rectus, lateral rectus, superior rectus, superior oblique) EXCEPT inferior oblique muscle that does not insert posteriorly

Answer 471

LFT SOV NASO2 Extraconal: - Lacrimal nerve (V1) - Frontal nerve (V1) - Trochlear nerve (IV) - Superior ophthalmic vein Intraconal: - Nasociliary nerve (V1) - Abducens nerve (VI) - Sympathetic nerve plexus - Occulomotor (superior and inferior) III

Answer 472

In retrobulbar anaesthesia, intraconal structures are blocked, i.e. NASO2 So occulomotor nerve blocked (superior rectus, medial rectus, inferior rectus, inferior oblique) and abducens nerve (lateral rectus) Trochlear nerve lies outside muscle cone, therefore superior oblique muscle is spared

Answer 473

TWO VEINS: 1) Superior ophthalmic vein 2) Inferior ophthalmic vein

Answer 474

- forms from supraorbital vein and angular vein - passes across superior orbit - pass through superior orbital fissure to enter cavernous sinus

Answer 475

- from muscles and posterior part of eye - passes inferiorly in orbit = joins with superior orbital fissure or = pass through superior orbital fissure to join cavernous sinus or = pass through inferior orbital fissure to join pterygoid venous plexus

Answer 476

Posteromedial aspect of orbital floor, usually medial to infraorbital nerve which may be damaged

Answer 477

Implant is placed as bridge along orbital floor

Answer 478

Inferior nasal meatus

Answer 479

When blinking, closure of eye closes puncta and squeezes lacrimal sac which form partial vacuum when eye reopens, there will be release of pressure and entry of tear fluid to eye

Answer 480

1) Protect globe (blink relfex) 2) Maintain ocular surface via lacrimal gland and sebaceus glands 3) Assist in focus by squinting 4) Control lighting 5) Convey emotion 6) Sexual dimorphism

Answer 481

1) Skin and sebaceous tissue 2) obicularis muscles 3) Orbital septum 4) preaponeurotic fat 5) Refeactor muscles 6) Tarsus 7) Conjunctiva

Answer 482

Preauricular node (upper) and submandibular nodes (lower)

Answer 483

Asian VS Caucasian Fuller VS less full Lower fusion of orbital septum VS higher Lower eyelid crease VS higher lower tarsal height VS higher lower levator function VS higher

Answer 484

Nasopharyngeal space behind the tubal elevation of auditory tube (common NPC place)

Answer 485

(nerve to medial pterygoid muscle) - tense soft palate

Answer 486

(pharyngeal plexus) - raise soft palate

Answer 487

(pharyngeal plexus) - Pulls tongue upwards

Answer 488

(pharyngeal plexus) - elevates wall of pharynx

Answer 489

(pharyngeal plexus) | - elevates uvulae

Answer 490

- Interdigitates with buccinator at pterygomandibular raphe | - sides of the oral floor

Answer 491

- hyoid bone from angle between greater and lesser horns

Answer 492

Thyropharyngeus: thyroid cartilage Cricopharyngeus: cricoid arch

Answer 493

Push food into oesophagus except cricopharyngeus, which acts as a sphincter that normally contracted to prevent food from going down, and relaxes during swallowing

Answer 494

Pharyngeal fascia: 1) External thin layer - bucopharyngeal fascia 2) Internal thick layer - pharyngobasilar fascia

Answer 495

(All run down to attach to thyroid cartilage) Salpingopharyngeus - auditory tube cartilage Palatopharyngeus - soft palate Stylopharyngeus - deep styloid process between superior and middle constrictor

Answer 496

Lift up the larynx during swallowing

Answer 497

1) Cricopharyngeus (CN X) | 2) Stylopharyngeus (CN IX)

Answer 498

Two on each side of oropharynx between palatoglossus (front) and palatopharyngeus (back) - separated laterally from carotid sheath of capsule of fibrous tissue

Answer 499

Tonsillar branch of Facial and ascending pharyngeal arteries

Answer 500

Jugulodigastric lymph node

Answer 501

Above vocal folds:internal laryngeal nerve (branch of superior laryngeal nerve) Below vocal folds: recurrent laryngeal nerve

Answer 502

Phayngeal venous plexus, drains to internal jugular vein (may communicate with pterygoid venous plexus)

Answer 503

Mostly goes directly to superior deep cervical nodes (some go to retropharyngeal nodes)

Answer 504

Oral phase (Voluntary): - chewing - styloglossus push bolus upward and backward to oropharynx - levator veli palatini elevates soft palate to close nasopharynx - starts swallowing reflex Pharyngeal phase (involuntary): - palatoglossus constrict the opening of oropharynx to push food further backward - stylopharyngeus, salphingopharyngeus, palatopharyngeus and thyrohyoid muscles elevates larynx so that epiglottis covers the glottis - vocal folds close - pharyngeal constrictors contracts to help with peristalsis - cricopharyngeus and upper oesophageal sphincter relaxes to allow food to enter esophagus Esophageal phase (involuntary) - esophageal peristalsis - lower oesophageal sphincter relax - airway reopens - larynx down

Answer 505

- Connects upper margin of thyroid cartilage to hyoid bone | - pieced by the laryngeal vessels and internal laryngeal nerve

Answer 506

- attach medial surface of thyroid cartilage to cricoid cartilage - Upper margins form vocal ligaments (interior of vocal folds)

Answer 507

Anteriorly to thyroid cartilage Posteriorly to vocal process of arytenoid cartilage

Answer 508

Rima glottidis -> entrance of lower respiratory tract

Answer 509

- Superior to cricothyroid membrane - from epiglottis to apical process of arytenoid cartilage and thyroid cartilage - lower border is free and thickened - lower border forms vestibular folds (false vocal cords)

Answer 510

Narrowing of laryngeal inlet (recurrent laryngeal nerve)

Answer 511

Narrowing of laryngeal inlet (recurrent laryngeal nerve)

Answer 512

pulls epiglottis down (recurrent laryngeal nerve)

Answer 513

Abduction of vocal folds (recurrent laryngeal nerve) | The only muscle that opens vocal folds to breathe --> work constantly to keep airway open (recurrent laryngeal nerve)

Answer 514

Adduction of vocal folds (recurrent laryngeal nerve)

Answer 515

Approximates the arytenoid cartilage (recurrent laryngeal nerve)

Answer 516

Tense the vocal fold -> higher notes (external laryngeal nerve from superior laryngeal nerve of CNX)

Answer 517

Shortens vocal folds

Answer 518

Tenses the cord and brings the edge of vocal folds upward during abduction

Answer 519

Herniation of mucosa (sinus leading to saccule) Saccule contains mucous glands that moistens vocal folds and prevent damage

Answer 520

To cranial cavity - foramen ovale, foramen spinosum To orbit: Inferior orbital fissure To pterygopalatine fossa: pterygomaxillary fissure

Answer 521

Between mandibular condyle and gleaned fossa of temporal bone - synovial joint, lax capsule anteriorly - biconcave intra-articular disc

Answer 522

elevates mandible, assist the protrusion of lower jaw, move the mandible medially

Answer 523

Major protrude of lower jaw, assist medial movement

Answer 524

Mainly lateral pterygoid assisted by medial pterygoid

Answer 525

posterior fibres of temporalis, deep head of masseter digastric, geniohyoid

Answer 526

anterior fibres of Temporalis, masseter, medial pterygoid

Answer 527

Gravity | - digastric, geniohyoid, mylohyoid

Answer 528

anterior fibre elevates jaw; posterior fibre retracts mandible, assist side-to-side action

Answer 529

elevation and retraction of mandible

Answer 530

(V3 trunk branch) - enters foramen spinosum - sensory input to dura mater in middle cranial fossa

Answer 531

(V3 trunk branch) Motor and sensory to: - medial pterygoid muscle - tensor veli palatini - tensor tympani

Answer 532

(V3 anterior branch) motor: | - lateral pterygoid

Answer 533

(V3 anterior branch) Sensory: | - to cheek (skin, mucosa, buccal gingivae)

Answer 534

(V3 posterior branch) - sensory to skin over temple, external ear, external acoustic meatus, tympanic membrane, TMJ - carries parasympathetic secretomotor fibres of CN IX from otic ganglion to parotid gland

Answer 535

(V3 posterior branch) - sensory to lower teeth and associated gingivae, mucosa and skin - motor branch to mylohyoid (branch to form incisive and mental nerve)

Answer 536

(V3 posterior branch) - sensory to anterior 2/3 tongue, mucosa of oral cavity floor, lingual gingivae - joined by chords tympani to provide special sensation to anterior 2/3 of tongue and parasympathetic fibres to all salivary glands below level of oral fissure

Answer 537

Branch of facial nerve (VII) - passes through petrotympanic fissure - joins lingual nerve medial to lateral pterygoid muscle - special sensation of taste to anterior 2/3 of tongue - presynaptic parasympathetic fibres to submandibular ganglion, which supplies sublingual and submandibular glands and tongue blood vessels

Answer 538

Hangs from lingual nerve at lateral surface of hyoglossus - carries secondary cell bodies for chords tympani - postsynaptic fibres travel along lingual nerve to sublingual and submandibular glands

Answer 539

From tympanic plexus (CN IX), descend at foramen ovale - Otic ganglion - > postsynaptic fibres join auriculotemporal nerve

Answer 540

1st: Between neck of mandible and sphenomandibular ligament 2nd: related to lateral pterygoid muscle 3rd: In pterygopalatine fossa

Answer 541

- network of veins between medial and lateral pterygoid muscles, and lateral pterygoid and temporals - drains nasal cavity, roof and lateral wall of oral cavity, all teeth, infra temporal fossa, paranasal sinus and nasopharynx - Anterior: Deep facial vein - Posterior: Short maxillary vein -> retromandibular vein - Inferior ophthalmic vein from orbit - communicates with cavernous sinus through infraorbital vein, inferior ophthalmic vein and emissary vein

Answer 542

Carotid canal

Answer 543

Through transverse foramina of upper six cervical vertebrae Enters cranial cavity through foramen magnum

Answer 544

Choroid and sclera of eyes

Answer 545

Between different arteries: 1) Superficial temporal and posterior auricular 2) superficial temporal and supraorbital 3) Dorsal nasal and angular artery Between same artery from different sides: 4) Right and Left superficial temporal arteries

Answer 546

Facial vein (continuation of angular vein by joining of supratrochlear and supraorbital veins) - drains into internal jugular vein directly or indirectly via common facial vein - communicates with cavernous sinus via superior and inferior ophthalmic veins - communicates with pterygoid venous plexus via infraoribital and deep facial veins

Answer 547

Formed by joining of superficial temporal vein and maxillary vein - anterior branch: joins facial vein to form common facial vein - posterior branch: joins posterior auricular vein to form external jugular vein

Answer 548

- formed by posterior auricular vein and posterior branch of retromandibular vein - crosses Sterncleidomastoid Receives: - suprascapular - transverse cervical - anterior jugular vein - ends in subclavian vein

Answer 549

Descend on either side of neck midline - drains anterior aspect of neck and enters EJV or subclavian vein

Answer 550

- begins in jugular foramen as continuation of sigmoid sinus - descend in carotid sheath, joins subclavian veins to form brachiocephalic vein - superior bulb at beginning and inferior bulb at termination - receives blood from brain, H&N

Answer 551

- do not cross foramen magnum - formed by small veins around skull base - enters transverse foramen of axis (C1) - descend with vertebral artery, ends in brachiocephalic or subclavian veins

Answer 552

Location: each side of the sella turcica and sphenoid bone body Lateral wall: CN III, IV, V1, V2 Internal carotid artery and CN VI pass through it Communicates with pterygoid venous plexus by emissary veins and receive blood from superior and inferior ophthalmic veins

Answer 553

Collect blood from vertebral column and drain into portal and systemic veins Communicate with intracranial dural venous sinuses i.e. occipital and basilar ** (important conduit for retrograde metastases from pelvis or abdomen to cranial cavity)

Answer 554

Collect blood from vertebral column and drain into portal and systemic veins

Answer 555

A) GAZE STABILIZATION 1) Vestibulo-ocular system (pre-rotatory and post-rotatory nystagmus, transitional VOR, ocular counter-rolling) 2) Optokinetic system (Visually evoked optokinetic nystagmus) B) GAZE SHIFTING 1) Smooth pursuit system 2) Saccadic system 3) Vergence system

Answer 556

Stabilization of retinal image during body movements (e.g. head rotation, linear motion, or head tilts)

Answer 557

1) Canal mechanism i.e. fluid movement during acceleration and deceleration leads to vestibular afferent discharge 2) Magnitude modulated by vestibulocerebellum - where follicular purkinje cells inhibit vestibular nuclear neurons 3) When head stops, eyes are held in position by cerebellar flocculus, vestibular nucleus, and prepositus hypoglossal.

Answer 558

Slow initial phase (2s) countering the rotation Fast late phase (0.2s) towards side of rotation

Answer 559

Activated by movement of entire visual world -> Stabilise gaze by holding image on the visual world steady on retina (especially useful during constant speed sustained head rotation as vestibule-ocular signal subsides)

Answer 560

SUBCORTICAL: Retina neurons -> CNII -> Pretectal nucleus -> Vestibular nucleus that integrates vestibular and visual inputs -> occulomotor nucleus in reticular formation CORTICAL: Striate cortex and middle temporal cortex -> pontine nuclei -> cerebellar flocculus -> occulomotor area in reticular formation

Answer 561

Triggered by moving visual stimulus that slides across stationary visual background Voluntary conjugate eye movement that keep moving target on fovea (foveal fixation) and reduce unwanted eye drifts

Answer 562

Gaze center is in paramedian reticular formation (midbrain center for vertical gaze, pontine center for horizontal gaze) Same pathway as optokinetic system: SUBCORTICAL: Retina neurons -> CNII -> Pretectal nucleus -> Vestibular nucleus that integrates vestibular and visual inputs -> occulomotor nucleus in reticular formation CORTICAL: Striate cortex and middle temporal cortex -> pontine nuclei -> cerebellar flocculus -> occulomotor area in reticular formation

Answer 563

Gaze center is in paramedian reticular formation (midbrain center for vertical gaze, pontine center for horizontal gaze) Same pathway as optokinetic system: SUBCORTICAL: Retina neurons -> CNII -> Pretectal nucleus -> Vestibular nucleus that integrates vestibular and visual inputs -> occulomotor nucleus in reticular formation CORTICAL: Striate cortex and middle temporal cortex -> pontine nuclei -> cerebellar flocculus -> occulomotor area in reticular formation

Answer 564

Triggered in response to sound, tactile stimulus, and memory of location in space Rapid conjugate eye movement that move fovea rapidly from one target to another (no time for visual feedback to modify saccade course)

Answer 565

Motor commands from frontal and supplementary eye fields via superior colliculus and basal ganglia, and Saccade generator: 1) Burst reticular cells (pulse discharge to drive eyes rapidly to new position; eye velocity command that overcome orbital viscous lag) 2) Tonic cells in prepositus hypoglossal nucleus or medial vestibular nucleus (step discharge to hold eye in place; eye position command against orbital elastic restoring force) 3) Inhibitory reticular cells (prevent unwanted eye movements) --> relayed to oculomotor area in reticular formation

Answer 566

Dysconjugate eye movement to align image on both fovea

Answer 567

Controlled by midbrain neutrons close to IIIrd nucleus

Answer 568

Laminar organization of photoreceptors, bipolar cells and retinal ganglion cells: 1) Photoreceptor: Cones and rod cells, different modality (red green VS blue yellow) 2) Bipolar cells: Concentric center-surround receptive fields (Centre and surround antagonistic in nature) 3) Retinal ganglion cells: Concentric center-surround receptive fields (On centre and off centre cells; M cells and P cells)

Answer 569

CONE VS ROD i) daytime VS night-time vision ii) Color VS B&W vision iii) small receptive field VS large receptive field iv) less convergence thus higher acuity VS high convergence thus lower acuity v) One kind of Blue, green, red pigments VS rhodopsin

Answer 570

Concentric center-surround receptive fields 1) On centre cells - depolarise to illumination (hyperpolarise to illumination of off-surround cells via GABA lateral inhibition of horizontal cells) 2) Off centre cells - depolarise to darkness (hyperpolarise to darkness of on-surround cells via GABA lateral inhibition of horizontal cells)

Answer 571

Concentric center-surround receptive fields 1) On centre cells (depolarise to light on) and Off centre cells (depolarise to light off) 2) M cell vs P cell - M: large receptive field, contrast, form, movement - P: small receptive field, fine detail, color discrimination

Answer 572

Concentric center-surround receptive fields; M cell VS P cells 1) Left visual field stimuli go to right LGB; right visual field go to left LGB 2) Inputs from 2 eyes are segregated by synapsing on alternate cell layers 3) Inputs from M cells and P cells are segregated by synapsing on alternate cell layers, Magnocellular pathway ventrally (movement, form, contrast) and parvocellular pathway dorsally (fine details, colour discrimination)

Answer 573

1) Receptive field -> functional hierarchy transforms receptive field to rectangular receptive field: - Directional selectivity for moving stimulus - Orientation selectivity (simple cell in orientation columns detects orientation, convergent to different complex cell for 2-level orientation detection, which then convey to hyper-complex cells in modular organization) 2) Modular organisation Interaction between cortical modules lead to visual perception Binocular receptive field helps with depth perception - Orientation columns (vertical columns of simple cells with different axis of orientation) - Ocular dominance columns (alternating columns from right or left eyes) - Blobs (cell column responsive to different colour stimulus) 3) Parallel pathways - Distinct M and P pathways from LGN; Ventral M pathway (form, movement, contrast), Dorsal P pathway (colour, fine details) - Segregate pathway beyond striate cortex: Ventral stream (spatial task, form & color recognition, visual memory); Dorsal stream (motion perception)

Answer 574

Ca10 (PO4)6 OH2

Answer 575

1) Isotinic secretion - secretogogue (Ach) increase acinar cell intracellular Ca - opening of basolateral Ca activated K channel and apical Cl channel - K efflux to interstitium, Cl efflux to acinar lumen - Na from interstitium to lumen by following Cl electrical gradient, via transcellular tight junction - osmotic gradient by NaCl cause transepithelial water migration from interstitium to lumen - Basolarteral Na K Cl cotransporter and Na K ATPase energize Cl replenishment (HCO3 ions can replace Cl by carbonic anhydrase action on CO2; HCO3 efflux via apical Cl channel; H efflux by basolateral Na H exchanger) 2) Hypotonic secretion - striated duct cell's Na K ATPase actively extrude Na back to blood, Cl follow passively - Na Cl diffuse from lumen to cell - Water cannot as ductal apical membrane is water impermeable - hypotonic saliva produced

Answer 576

- sympathetic stimulation of beta adrenoceptor leads to increase cAMP, thus activating PKA - phosphorylation activates target protein, and lead to polypeptide and protein synthesis, storage and release Plasma protein e.g. IgA are endocytosed by acinar cells, then transcellular translocation to apical membrane, then released by exocytosis (in pathological condition plasma protein enter saliva via paracellular route)

Answer 577

1) Allow mucociliary transport to remove materials deposited in nose 2) protection with Ig (IgA) and bacteriocidal proteins 3) Air conditioning by warming and humidifying inhaled air 4) Olfaction (modify inhaled odors)

Answer 578

1) Anterior nasal glands in vestibule - serous 2) Submucosal glands in respiratory and olfactory region - seromucous 3) Secretory cells in respiratory epithelium - mucous 4) Plasma exudate in pathological conditions

Answer 579

A) Neural: 1) Sympathetic nerve - induce protein secretion (beta adrenoceptor) and vasoconstriction that reduce fluid supply (alpha) -> SCANTY SECRETION 2) Parasympathetic nerve - electrolyte transport and vasodilation (muscarinic Ach) -> COPIOUS SECRETION 3) Sensory nerve - VIP leads to vasodilation -> more fluid supply this COPIOUS SECRETION B) Inflammatory mediators 1) Histamine, bradykinin, prostaglandin - induce electrolute transport on glandular receptor - vasodilation - increase vascular permeability - activate sensory nerve and parasympathetic nerves

Answer 580

``` Complex mixture of sensory input of: 1) Olfaction (smell) 2) Gustation (taste) 3) Tactile sensation (texture) of food as it is being chewed ```

Answer 581

- odorant molecule diffuse from air to olfactory epithelium - dissolve in mucus and bind to different types of olfactory receptors on cilia of olfactory cells (each olfactory cell express one type of odourant receptor - Binding activates Golf, increasing Na Ca conductance, leading to depolarise and fire neural discharge of cell - sensory cells bearing same receptor have axons converge to same glomeruli on the olfactory bulb - the distinct firing combination of olfactory neurons and activated glomeruli are translated by brain to diverse odour perception

Answer 582

Circumvallate papilla Foliate papilla Fungiform papilla

Answer 583

``` Floral (rose) Ethereal (pear) Musky (musk) Camphor (eucalyptus) Putrid (rotten egg) Pungent (vinegar) ```

Answer 584

- Sour (warn against intake of potentially poisonous chemicals) - Sweet (identification of energy-rich nutrients) - Bitter (warn against intake of potentially poisonous chemicals) - Umami (glutamate, identification of L-amino acid) - Salty (Proper dietary electrolyte)

Answer 585

T1R2 + T1R3 heterodimer GPCR, activated G protein release G beta gamma that activate PLC that cleaves to form IP3 and DAG, secondary messengers finally depolarise the cell and stimulate connected neurons to relay nerve signal

Answer 586

H+ influx via H+ ion channels (PKD2L1) to depolarize taste cells and stimulate connected neurons to relay nerve signal

Answer 587

T1R1 + T1R3 GPCR, activated G protein release G beta gamma that activate PLC that cleaves to form IP3 and DAG, secondary messengers finally depolarise the cell and stimulate connected neurons to relay nerve signal

Answer 588

T2R GPCR, activated G protein release G beta gamma that activate PLC that cleaves to form IP3 and DAG, secondary messengers finally depolarise the cell and stimulate connected neurons to relay nerve signal

Answer 589

Taste receptor cells are assembled into taste buds, located within tongue papilla (circumvallate, foliate, fungiform) Labelled line model (MORE LIKELY): Each taste quality is specified by non overlapping cells and fibres, i.e. each TRC respond to one taste and innervated by nerve fibres tunes to the taste Across Fibre model: each individual TRC tuned to one/multiple taste qualities, and each afferent fibres carry information for more than one taste qualities

Answer 590

ENaC (epithelial sodium channel) Na+ influx via Na+ ion channels to depolarize taste cells and stimulate connected neurons to relay nerve signal

Answer 591

Labelled-line model in periphery Beside taste quality, neurons also record other attributes of chemical stimuli e.g. intensity of the taste and whether it is pleasant, neutral or unpleasant

Answer 592

Collection and localisation of sound, conduct sound to tympanic membrane by air

Answer 593

1) Impedance matching - air borne vibration stops at ear drum, fluid vibration starts at fenestra vestibuli; matching of the 2 media achieved by: a) Leverage of ossicles b) Area-ratio between larger tympanic membrane and small oval window 2) Sound attenuation (during exposure to loud sound or vocalisation) via middle ear muscle (tensor tympani, staepidius) reflex to protect inner ear and improve speech discrimination in noise

Answer 594

Sound attenuation (during exposure to loud sound or vocalisation) to: i) Protect inner ear ii) Improve speech discrimination in noise

Answer 595

(Mainly inner hair cells, outer hair cell plays minimal role) - oval window vibration from ossicles leads to perilymph vibration in Vestibular canal - vibration transmit to endolymph in cochlear duct and displace basilar membrane - Displacement of basilar membrane creates shearing force that displace hair cell's cilia embedded in the tectorial membrane - Opens pressure gated K+ channel on stereocilia and kinocilia, K+ influx leads to hair cell depolarisation - depolarisation opens voltage-gated Ca++ channel, which prompt neurotransmitter exocytosis - generator potential at auditory nerve

Answer 596

INNER VS OUTER More involved in sound sensation transmission VS less involved 1:10 afferent connection/divergence VS >10:1 afferent connection/convergence Less VS more (1:3) supply 95% afferent VS 5% afferent

Answer 597

Place coding: the cochlea is tonotopically represented based on physical property of basilar membrane: i) Basal portion (stiff, narrow, short stereocilia) respond to high frequency ii) Apex portion (floppy, wide, long stereocilia) respond to low frequency Thus frequency of tone determines peak position of travelling wave along basilar membrane; wave subsides rapidly beyond optimal displacement with sharp cut off at apex

Answer 598

Mechanical layout of organ of Corti amplifies very small vibrations Descending efferent modulation --> Outer hair cells amplify mechanical vibration of basilar membrane by shortening the length of cell body (motor from descending auditory pathway) -> alter sensitivity of hair cells to improve detection of weak sound against background noise (selective filtering)

Answer 599

V-shaped tuning curve - tip of curve is characteristic frequency (signifies the locus of hair cell on the basilar membrane with which auditory fibre innervates) - sharply tuned to exclude frequency above CF - permits discrimination of very soft tones with slightly different frequency

Answer 600

- Auditory nerve (sound intensity and frequency processing) - > Brainstem's Cochlear nucleus & superior olivary complex - > Midbrain's inferior colliculus - > Thalamus' MGB - > Cortical centres

Answer 601

Lower brainstem centers (shows progressive sharpening of tuning curves to ENHANCE frequency discrimination): 1) Cochlear nucleus ro analyse intensity and frequency 2) Superior olivary complex for Binaural processing (compare time and intensity cue from both ears) for gross discrimination of sound direction

Answer 602

Inferior colliculus: - detect frequency modulation and amplitude modulation in speech - reflex center for sound orientating response and startle response - descending projection from auditory cortex to modulate ascending signals

Answer 603

Medial geniculate body - ascending relay to auditory cortex - descending projection from auditory cortex to modulate ascending signals

Answer 604

1) Functional column in area 41, 42: - isofrequency bands (rostral low; caudal high) - biaural bands (right vs left ear) 2) precise localisation of sound in space 3) Broca's (44, 45) and Wernicke's (22) to process complex sound of language

Answer 605

1) Pure tone audiometry (measure hearing threshold in terms of intensity and frequency) 2) Brainstem auditory evoked response (click evoked neural activity to assess hearing ability of esp infants)

Answer 606

1) Subjective sensation of motion and spatial orientation (vestibulo-cortical perception) 2) Stabilization of eyes in space during head movements (vestibulo-ocular reflex) 3) Adjustment of muscle activity and posture to prevent falling (vestibulo-spinal reflex)

Answer 607

By hair cell (kinocilia and stereocilia) Head movement introduces shearing force: - bending of stereocilia to kinocilium depolarises the receptor cell (increase vestibular nerve firing) - bending of kinocilium towards stereocilia hyperpolarizes the cell (decrease firing)

Answer 608

Detects angular acceleration (i.e. rotation) of head in 3-D space - canals on 2 sides work as complementary pairs (increase firing of one vestibular nerve means decrease firing of the other side's) - At onset of rotation, acceleration leads to lagging of endolymph in canal due to inertia, shearing force that displace hair cells, depolarize - constant speed rotation -> no acceleration, cilia back to normal - At end of rotation, endolymph displace in opposite direction due to inertia, shearing force that displace hair cells, hyperpolarize

Answer 609

Utricle in horizontal plane Saccule in vertical plane

Answer 610

Detects linear acceleration or head tilt - multidirectional orientation of polarisation axis for utricle - Up-down orientation of polarisation axis for saccule - Head movement in particular direction increase the excitability of one subgroup and decrease another on the same otolith organ

Answer 611

1) Compensatory vestibular relfexes - vestibulo-spinal reflexes (balance posture with antigravity muscles) - vestibulo-ocular reflexes (otolith related and canal-related) 2) Subjective orientation: vestibulo-thalamo-cortical projection for conscious awareness of motion and body orientation 3) Disturbances associated with motion sickness -> autonomic nervous system foe nausea and dizziness

Answer 612

1) Counter rolling (aka Doll's eye reflex) - 50º lateral tilt for 5º counter rolling 2) Translational VOR: - Linear acceleration of 1m/s^2 -> 4º derivation of A-P parallel swing

Answer 613

Vestibular Nystagmus Pre rotatory and post rotary Slow phase and fast phase

Answer 614

1) Elevation of larynx and folding of epiglottis to cover laryngeal inlet 2) Closure of false cords 3) closure of glottis 4) Generation of positive subglottic pressure

Answer 615

Intraluminal (eg lodged food) Intramural (esophageal tumour) Extraluminal (large lymph nodes)

Answer 616

A) Mucosal layer: pseudostratified epithelium with goblet cells superiorly and inferiorly; non-keratinising squamous epithelium at contact surface of medial cord B) Subepithelial tissues: three layered lamina propr.: i) Superficial Reinke's space (allow free vibration of epithelium) ii) Intermediate layer (part of vocal ligament) iii) Deep layer (part of vocal ligament) Note: vocal ligament formed by free thickened edge o quadrangular membrane

Answer 617

``` Mandible - CN V Lips - CN VII Larynx - CN X Soft palate - CN XI Tongue - CN XII ```

Answer 618

force of expiration -> Lung function strength of respiratory muscles

Answer 619

Vocal folds - Size (larger -> lower) - Tension and length (tenser -> higher) - Intrinsic laryngeal muscle strength

Answer 620

Revisit if have time

Answer 621

A mixed nerve formed from fusion of Ventral root (motor nerve) and Dorsal root (sensory nerve)

Answer 622

1) Only gray rami communicans in cervical spinal nerves | 2) White and grey rami communicans in (T1 - L2?)

Answer 623

Level of T1 to L2 - cell bodies of sympathetic motor fibres, which axon extend into same of different level sympathetic ganglion via white ramus communicans

Answer 624

Somatic VS visceral - somite derived outer body tube VS inner body tube - One neuron chain (CNS -> skeletal muscle) VS two-neuron chain (CNS -> autonomic ganglion -> smooth muscles) - Supplies skin, skeletal muscles and vertebrae VS smooth and cardiac muscles, and glands

Answer 625

- somite derived outer body tube VS inner body tube - One neuron link (both) - Both's cell body lie collected together in PNS as sensory ganglion (EXCEPT some proprioceptive neurons have cell body in CNS)

Answer 626

Formed by ventral rami of C1-C4 cervical spinal nerves, gives rise to cutaneous sensory and motor branches: 1) Sensory: - Lesser occipital - Greater auricular - transverse cervical - supraclavicular 2) Motor: - C1 to geniohyoid and thyrohyoid - C1 - C3 (Ansa cervicalis) to infrahyoid muscles (Sternohyoid, sternothyroid, omohyoid) - C4 Phrenic nerve to diaphragm - nerve twigs to prevertebral muscles (longus capitis and cervicis)

Answer 627

Midpoint along posterior border of sternocleidomastoid

Answer 628

III Ciliary VII Pterygopalatine VII Submandibular IX Otic

Answer 629

A mixed nerve carried by somatic sensory branches of trigeminal nerve; contains sensory fibres of CN V, parasympatheic visceral motor fibers from CN, and sympathetic nerve from superior cervical ganglion (only parasympathetic synapse in ganglion)

Answer 630

1) sensory fibres of CN V 2) parasympatheic visceral motor fibers from CN III VII IX 3) sympathetic visceral motor nerve from superior cervical ganglion

Answer 631

CN V: V1 nasociliary nerve -> sensory of cornea and iris Sympathetic: Sup Cerv Gang -> dilator pupillae and blood vessels Parasympathetic: Edinger Westphal Nuc -> ciliary ganglion -> sphincter pupillae and ciliary muscles

Answer 632

CN V: V2 -> Sympathetic: Sup Cerv Gang -> Deep petrosal nerve -> Parasympathetic: Superior salivary nucleus -> Greater petrosal nerve -> pterygopalatine ganglion ->

Answer 633

{CN V: V3 Lingual nerve -> anterior 2/3 tongue sense (DOES NOT PASS THROUGH GANGLION!!)} CN VII: Chorda tympani -> taste to anterior 2/3 Sympathetic: Sup Cerv Gang -> Submandibular and sublingual glands Parastympathetics: Superior salivary nucleus -> joins chorda tympani -> synapse in submandibular ganglion -> joins lingual nerve -> submandibular and sublingual glands (note: all post ganglionic fibres except sympathetics join lingual nerve)

Answer 634

CN V: V3 auriculotemporal nerve -> parotid fascia sensory Sym: Sup Cerv Gang -> joins auriculotemporal nerve -> parotid arteries Parasym: Inferior salivary nucleus -> tympanic plexus -> lesser petrosal nerve -> otic ganglion -> joins auriculotemporal nerve -> Parotid gland

Answer 635

1) Pregnaglionic sympathetic motor nerve cell bodies in interomediolateral horn of T1 - T2 2) Fibres ascend through sympathetic chain to reach superior cervical ganglion 3) Postgnalgionic fibres return to cervical spinal nerves or BVs via gray rami communicans 4) Travel along blood vessels to reach target

Answer 636

Superior (largest) Middle Inferior - lies on longus capitis muscle about level of 2nd and 3rd vertebral body - Gives off gray rami communicans

Answer 637

CRANIAL NERVE: - Face by V1 V2 V3 (think of the face guy) SPINAL NERVE: - dorsal rami of cervical spinal nerve supplies back of head and neck - cervical plexus supplies front and side of neck

Answer 638

Parotid gland - serous or watery secretion Submandibular & sublingual glands - a mixture of serous and mucous fluid Small mucosal glands - mucous secretion

Answer 639

(superficial to deep) - facial nerve and branches - retromandibular vein - external carotid artery

Answer 640

Form complex with thrombin or Factor Xa with heparin from endothelial cells to inhibit thrombin and Factor Xa, thus no activity and start anti-coagulation pathway

Answer 641

Bound to thrombomodulin -> protein C activation, Factor Vac, together with S, inactivate factor VIIIa Bound to antithrombin III to form complex with heparin as well, inactivate thrombin

Answer 642

GBM LP FLAT GH Beta endorphin MSH Lipotrophin Prolactin FSH LH ACTH TSH

Answer 643

ADH | Oxytocin

Answer 644

Sella turcica, a cavity of sphenoid bone

Answer 645

Neuroectoderm. The neural component – evaginates from the floor of the diencephalon and grows caudally. becomes posterior lobe Oropharyngeal ectoderm. The oral component arises as an out-pocket from the roof of the primitive mouth, forming the Rathke’s pouch. Becomes anterior lobe

Answer 646

Anterior lobe (adenohypophysis): pars tuberalis, pars intermedia, pars distalis Posterior lobe (neurohypophysis): Extension of neuroectoderm via infundibulum; neural fibres, palely stained

Answer 647

From Internal carotid artery: 1) Right and left superior hypophyseal arteries -> forms primary capillary plexus (supply median eminence and infundibulum) -> form veins and secondary capillary plexus in adenohypophysis (**hypophyseal portal system) 2) Right and left inferior hypophyseal arteries -> supplies neurohypophysis and a small supply to infundibulum => hypophyseal veins

Answer 648

1) Oxytocin and ADH: peptides produced by aggregates of neurons in the supraoptic and paraventricular nuclei of the hypothalamus => transported along axons, accumulated at the end of axons in the neurohypophysis => release to blood capillaries 2) Releasing hormones: peptides produced by neurons of the dorsal medial, ventral medial and infundibular nuclei of hypothalamus => carried along axons ending in median eminence where they are stored and secreted => enter the capillaries of the median eminence and transported to the adenohypophysis via the hypophyseal portal system for stimulation 3) proteins and glycoproteins secreted by endocrine cells in pars distalis. They are liberated into the secondary capillary plexus of the portal system and are distributed to the general circulation

Answer 649

Location: wall of the infundibulum - the neuro-haemal region where the neurohormones pass into the capillaries - surrounded by extended perivascular connective tissue spaces where axon endings open into

Answer 650

cords of epithelial cells interspersed with capillaries - chromophobe - Chromophile (acidophil, basophil)

Answer 651

GH, Prolactin secretion

Answer 652

FSH LH ACTH TSH

Answer 653

funnel shaped region surrounding infundibulum cells of this region secrete gonadotrophins and are arranged in cords alongside with blood vessels

Answer 654

made up of cords and follicles of weakly basophilic cells containing basophilic granules developed from dorsal part of the Rathke’s pouch.

Answer 655

- Composed of unmyelinated neurons - Neurosecretions accumulate at the end of the neurons to form Herring bodies - ADH and oxytocin joined to neurophysin, a binding protein

Answer 656

- GnRH (=> LH FSH) - CRG (Corticotropin-releasing hormone) => ACTH, MSH, beta endorphin - Thyrotropin-releasing hormone (TRH) => TSH & Prolactin - GHRH => GH - Somatostatin => decrease GH, TSH, prolactin - Dopamine => decrease prolactin

Answer 657

1. Long-loop: target gland hormone or metabolite on pituitary/hypothalamus - e.g. cortisol on ACTH/CRH 2. Short-loop: pituitary hormone on hypothalamus - e.g. ACTH on CRH - GH on somatostatin, SRIF) 3. Ultra-short-loop: within pituitary or hypothalamus - GHRH increases SRIF secretion

Answer 658

1) Binds to adrenal cortex membrane receptor that activates adenylate cyclase, increase cAMP, increase PKA 2) Stimulates the synthesis & secretion of mainly cortisol from the zone fasciculate of adrenal cortex (aldosterone mainly controlled by renin-angiotensin system)

Answer 659

Long loop: direct Cortisol on ACTH; indirect cortisol on CRH Short loop: ACTH on CRH

Answer 660

glycoprotein hormones consist of α and β subunits; β sequence being different for LH and FSH.

Answer 661

1) In female: Development of Graffian follicles -> Oestrogen production (for proliferative phase of endometrium & secondary sexual characteristics) 2) male: spermatogenesis

Answer 662

1) female: causes ovulation and maintains the corpus luteum, to produce Progesterone (Secretory phase of endometrium for implantation) 2) male: stimulate Leydig cell to produce testosterone (secondary sexual characteristic)

Answer 663

glycoprotein consists of α and β chains where α chain is identical to LH & FSH

Answer 664

1) Lactation in mammary gland alveoli 2) Inhibits hypothalamus and gonads, reducing the production and activities of gonadotrophins –> Breast-feeding women cannot get pregnant –> Reason: breast-feeding elevates prolactin level, which mediate an anti-gonadotrophic effect, causing a lack of ovulation

Answer 665

Uniquely regulated by inhibition mainly - Baby suckling of nipple activate mechanoreceptor, send signal to higher centre - hypothalamic PIH release inhibited, thus stimulating prolactin production in anterior pituitary

Answer 666

A) INDIRECT ACTION 1) causes liver to produce somatomedins/ insulin like growth factors (IGF), which ↑ glucose uptake and ↓ lipolysis initially 2) somatomedin stimulate bone growth at epiphysis of long bones - increases deposition of protein by chondrocytic & osteogenic cells - increases the proliferation of chondrocytic & osteogenic cells - promotes conversion of chondrocytes into osteogenic cells B) DIRECT ACTION 3) Promotes protein synthesis, decrease proteolysis 4) Enhances fat utilization for energy (enhance lipolysis and beta oxidation) 5) Decreases carbohydrate utilization; After a few hours: insulin antagonistic effect to ↓ glucose uptake and ↑ lipolysis; increased gluconeogenesis in liver

Answer 667

1) GHRH/somatostatin (pull-push mechanism) -> depend on ratio 2) Negative feedback: - blood glucose - somatomedins (IGF-1) 3) Other factors stimulate GH secretion: - fasting or starvation - hypoglycemia - ↓ plasma FFA - Exercise - Stress, trauma, excitement

Answer 668

1) stimulates V1 receptor on vascular smooth muscle to cause vasoconstriction to ↑ blood pressure 2) stimulates V2 receptor on distal and collecting ducts to increases water reabsorption by insertion of aquaporin 2

Answer 669

↑ Plasma osmolarity ↓ Circulating blood volume ↓ blood pressure

Answer 670

Effect on milk ejection (letdown reflex) - causes contraction of the myoepithelium of the breast Effect on the uterus - causes contraction in parturition (baby delivery)

Answer 671

Cortex (mesoderm) and Medulla (neuroectoderm) CORTEX 1. Zona glomerulosa: mineralocorticoids (Aldosterone) 2. Zona fasciculata: glucocorticoids (Cortisol) 3. Zona reticularis: androgens (DHEAS) MEDULLA - chromaffin cells that release catecholamine (epinephrine & norepinephrine) under sympathetic stimulation - Innervated by cholinergic preganglionic sympathetic neurones. Acetylcholine released binds to nicotinic receptors on chromaffin cells

Answer 672

1) ↓ Urinary excre

Answer 673

1) Renin‐angiotensin‐aldosterone system - kidney JXG cells produced Renin converts liver produced angiotensinogen to angiotensin I which is converted by lungs' ACE to angiotensin II - Angiotensin II increases growth & vascularity of zona glomerulosa, increases aldosterone synthesis 2) Plasma [K+] - higher plasma K increase aldosterone secretion 3) Atrial natriuretic peptide ANP - ANP released by atria in response to high BP, inhibits aldosterone secretion & renal Na reabsorption, resulting in diuresis & ↓ BP

Answer 674

Juxtaglomerular cells release Renin when: 1) ↓ perfusion pressure (dehydration, bleeding) 2) ↑ sympathetic stimualtion 3) decreased NaCl delivered to macula densa

Answer 675

BBIIG 1) Blood pressure maintenance (up regulation of alpha adrenoceptor on arterioles) -> INCREASE BP 2) BONE RESORPTION: Inhibits osteoblasts & protein synthesis; ↓ serum [Ca2+ ] by ↓ intestine and renal reabsorption; increase PTH for bone resorption 3) Immunosuppression and anti-inflammatory 4) 5) Glucose increase by gluconeogenesis, glycogenolysis, reduced glucose uptake 6) Mobilize protein (proteolysis) from non-hepatic tissues to liver for protein genesis 7) Fat : increase lipolysis, decreased lipogenesis Hypokalemia -> weak muscle Inhibits fibroblast proliferation & collagen formation -> striae Polycaethemia READ L21

Answer 676

1. Hypothalamic‐pituitary‐adrenal axis - paraventricular nucleus releases CRF -> anterior pituitary release ACTH -> cortisol from adrenal cortex 2. Diurnal rhythm - Diurnal rhythm of CRH, and thus ACTH & cortisol - Cortisol high in the morning, low in late afternoon & at night - Under control of suprachiasmatic nucleus SCN 3. Negative feedback - Long loop: Negative feedback of plasma cortisol on hypothalamic CRF & pituitary ACTH production - Short loop: plasma ACTH on CRF secretion 4. Stress increases CRH, ACTH & cortisol

Answer 677

- Adrenal androgen begins to appear after birth at about 5 years of age - DHEAS become detectable in the circulation at about 6 years of age (adrenarche) - contributes to the appearance of axillary & pubic hair at about 8 years old - Levels continue to increase, peak during mid‐twenties, and then progressively decline with age

Answer 678

In men, contribution of adrenal androgens to active androgens is negligible In female, adrenal contributes 50% of circulating active androgens, required for growth of axillary & pubic hair and for libido

Answer 679

1) BONE: 99% of calcium is found in the bone: - Most of it in the form of hydroxyapatite crystal, Ca10(PO4)6(OH)2, in large stable calcium pool that is slowly exchangeable by bone remodeling - surface of newly formed bones (amorphous calcium phosphate, CaHPO4); Readily exchangeable reservoir that is in equilibrium with ECF 2) MUSCLE: 0.3% of calcium is located in muscle 3) 0.1% of calcium is found in extracellular fluid: - ionized calcium (Ca2+); 50% - protein-bound (albumin & globulins); 40%; non-diffusible - complexed with anions e.g. citrate or phosphate; 10%

Answer 680

- Most of it in the form of hydroxyapatite crystal, Ca10(PO4)6(OH)2, in large stable calcium pool that is slowly exchangeable by bone remodeling - surface of newly formed bones (amorphous calcium phosphate, CaHPO4); Readily exchangeable reservoir that is in equilibrium with ECF

Answer 681

1) important component of intracellular pH buffering and various metabolic intermediates. 2) Bone component 3) DNA, RNA and phosphoproteins

Answer 682

86% in the bone, 14% in cells, and 0.08% in extracellular fluid - Most of the plasma phosphate is diffusible as inorganic orthophosphate (PO4)3- e.g. (HPO4)2- (80%) and (H2PO4)- (20%). - Non-diffusible phosphate is bound with protein (13%)

Answer 683

1) Nonhormonal regulation - Protein-bound calcium (buffer) - Exchangeable pool in bone (amorphous calcium phosphate) 2) Hormonal regulation - PTH - 1, 25 DOH Vit D - calcitonin - others like cortisol (bone resorption) TH (bone growth) GH (bone growth) Estrogen (prevent osteoporosis)

Answer 684

inferior thyroid arteries from thyrocervical trunk

Answer 685

- PTH is translated as a pre-prohormone - Cleavage of leader and pro-sequences in liver and kidneys - The C-terminal fragment (PTH-C) is an inactive peptide

Answer 686

(MAJOR) Decrease serum Ca++ or Mg++ will increase PTH Active vitamin D inhibits PTH gene expression, providing another level of feedback control of PTH.

Answer 687

A unique calcium receptor (CaSR) on the plasma membrane of parathyroid cells senses changes in extracellular [Ca2+]. The receptor coupled to both phospholipase C (activate) and adenylate cyclase (inhibit). Binding of Ca2+ to the receptor results in increased intracellular [Ca2+] and decreased in cAMP which prevents exocytosis of PTH from secretory granules.

Answer 688

increase plasma Ca2+ and decrease plasma phosphate: 1) increase distal tubule Ca reabsorption 2) increase phosphate excretion in proximal tubules 3) promotes the formation of 1,25-(OH)2 vitamin D in kidney to enhance GI Ca2+ absorption 4*) Increase bone resorption: i) fast phase on osteoblast and osteocyte: PTH promotes Ca2+ pump activity in the osteocytic membrane system (overlying the bone matrix with a thin layer of bone fluid), osteocytes take up Ca2+ from the bone fluid and transport it to ECF through the osteoblasts ii) indirect slow phase on osteoclasts (since no PTH receptor): activate osteosteoclastic activity, and promotes the proliferation of osteoclasts

Answer 689

1) In skin keratinocyte, 7-dehydrocholesterol is photo converted under UV to previtamin D, then spontaneously converts to vitamin D3. 2) Liver vitamin D 25-hydroxylase hydroxylate vitamin D3 yielding 25- (OH) vitamin D (calcidiol) - rate limiting step 3) Kidney VD3 1α-hydroxylase hydroxylate calcidiol yielding active 1,25- (OH)2 vitamin D (calcitriol) [stimulated by PTH and low Ca)

Answer 690

1) promotes the effect of PTH on bone resorption by increasing the activity of osteoclasts 2) stimulate absorption of Ca2+ from intestine epithelium by: - induces the production of calcium binding proteins (CaBP or calbindins) which sequester Ca2+, buffer high [Ca2+] that arise during initial absorption and allow Ca2+ to be absorbed against a high Ca2+ gradient - stimulates the production/activity of Ca2+ channel and transporter (TRPV6 & Na/ Ca exchanger) in intestinal epithelium. 3) also stimulates Ca2+ & PO43- reabsorption in kidney tubules (minor effect)

Answer 691

by the thyroid (parafollicular cells or “C” cells).

Answer 692

High PTH and low Ca++ stimulate Kidney VD3 1α-hydroxylase to produce active Vit D

Answer 693

decrease plasma Ca2+ and phosphate by: 1) Decreases bone resorption by inhibiting osteoclastic activity and inhibiting the proliferation of osteoclasts 2) Decreases renal Ca2+ reabsorption & promotes phosphate excretion.

Answer 694

Increased serum calcium leads to secretion

Answer 695

Endocrine: chemical substances that are secreted by living cells, and upon delivery by the circulation to a specific site, act to regulate reactions that elicit a typical response (e.g. insulin) Paracrine: acting on adjacent cells (e.g. somatostatin) Neurocrine: secreted at nerve endings (e.g. oxytocin) Autocrine: acting on the cell (or cell of the same type) that secretes it (e.g. T4) Neuroendocrine: neuocrine and endocrine e.g. somatostatin on GH secretion

Answer 696

Protein: prolactin Peptide: Insulin, glucagon Steroid: aldosterone, cortisol Amines: thyroxine, adrenaline from tyrosine Prostaglandins & cytokines (local hormones e.g. TNF alpha)

Answer 697

volume of plasma completely cleared of a hormone per unit time

Answer 698

1) Episodic secretion: secreted in pulses but not continuously e.g. GnRH 2) Diurnal rhythem: e.g. cortisol secretion highest in morning and lowest in evening 3) Cyclic secretion: complicated cycles e.g. LH, FSH, estrogen

Answer 699

1) Mobile receptor model (intracellular cytosolic or nuclear receptors) - steroid hormones => response by genome activation/ inactivation 2) Fixed receptor model (extracellular on plasma membrane) - peptides - catecholamine (cAMP, AC, calmodulin, DAG, IP3, JAK, TK) => response by protein phosphorylation 3) Multiple receptor model - e.g. TH; receptor both intracellular and extracellular

Answer 700

Vasopressin/ADH V1 receptor (via IP3) on vessels -> vasoconstriction V2 receptor (via cAMP) on distal tubule -> insertion of aquaporin 2

Answer 701

Sign: Objectively measurable, as perceived by doctors e.g. tachycardia Symptoms: Subjective, perceived by patient e.g. palpitation

Answer 702

Hypokalemia in hyperaldosteronism Hypercalcemia in hyperparathyroidism Proteolysis in hyperthyroidism Proteolysis of limb muscles in Cushing's Decrease release of Ach at NMJ in hypocortisolaemia

Answer 703

Association constant = [HR complex] / ( [free H] * [free R] )

Answer 704

X axis: value of bound hormone [HR] Y axis: ratio of bound to free hormone [HR]/[H] When H -> infinity, then Y axis is 0, and [HR] will reach highest level (i.e. maximum binding Bmax) ``` X-intercept = Bmax Slope = - Ka (association constant) ```

Answer 705

Thyroxine and insulin Fast action: act on existing molecule e.g. enzymes or transporter Slow action: increase number of molecule by protein synthesis

Answer 706

- level of RNA synthesis (steroid, GH, insulin) - level of ribosome (GH, insulin, thyroxine) - cAMP -> transcription (glucagon) or ribosome (ACTH)

Answer 707

Presented to allow other hormones to work (e.g. T4 up regulate beta adernoceptors; cortisol inhibits phosphodiesterase)

Answer 708

e. g. Cortisol direct: increase glycogenesis Permissive: increase glycogenolytic effect by glucagon and adrenaline (direct during feeding where high blood glucose inhibit glucagon; permissive during fasting as glucose produced in liver is released and not converted to glycogen)

Answer 709

1) change enzyme activity (insulin) (T4 stimulate mitochondrial enzyme for oxidative phosphrylation) 2) Change in substrate level (insulin increases glucose for glycolysis) (T4 increase ADP level by increasing transport into mitochondria and stimulating Na/K ATPase) 3) Change in product level (insulin stimulates glycolysis removing Acetyl CoA, the first step of FFA synthesis) (T4 increase transport of ATP out of mitochondria)

Answer 710

1) Redundancy (same physiological effect of different hormones -> ensure critical process will take place) - adrenaline and glucagon on glycogenolysis - adrenaline and GH in lipolysis 2) Reinforcement (different way, same end) - cortisol -> increase muscle proteolysis and increase liver enzyme for gluconeogenesis 3) Push-pull mechanism (dual control for precise regulation via negative feedback) - GH by GHRH and SRIF - glucose level by insulin and glucagon 4) Modulation of responding system - receptor: e.g. T4 downregulate TRH receptor; estrogen up-regulate LH receptor - post-receptor: inhibition of cAMP destruction? (i.e. permissive action)

Answer 711

Adrenaline (alpha beta); Noradrenaline (alpha): 1) CVS - increase cardiac output (beta 1, heart rate and stroke volume) - Blood pressure (alpha vasoconstriction, beta 2 vasodilation) 2) Metabolism (alpha and beta) - increase glycogenolysis, lipolysis, gluconeogenesis 3) Smooth muscle contraction - muscle contraction (alpha) - muscle relaxation (beta 2) (Same direction for GI tract)

Answer 712

close loop Negative feedback: to keep hormonal level more or less constant Positive feedback: to make level deviate more from norm -> amplification of level for action

Answer 713

LH surge for ovulation Oxytocin for uterine contraction during labour

Answer 714

Loss of 1 litre of blood => decrease BP => negative feedback via baroreceptor and volume retention => increase BP to normal Loss of 2 litres of blood => decrease BP => positive feedback from decreased venous return, decreased coronary perfusion => further vicious decrease in BP

Answer 715

Hypothalamus control Via kisspeptin - Negative feedback at arcuate nucleus - Positive feedback at anteroventral periventricular nucleus (puberty, preovulatory LH surge)

Answer 716

e.g. glucose in stress Higher glucose level in stress due to insulin decrease, glucagon increase, cortisol and adrenaline increase e.g. ACTH in stress Higher ACTH level in stress -> to further increase Cortisol

Answer 717

Anticipatory response to improve homeostasis e. g. increase of glucose in GI tract => increase GI hormone => increase insulin secretion e. g. Cephalic phase of eating => parasympathetics to increase insulin secretion RELEASE of insulin in anticipation of blood glucose increase

Answer 718

``` EXTERNAL FACTOR (open loop where output does not affect input) e.g. lighting, stress, cold ``` ``` INTERNAL FACTOR (close loop where output affect input) e.g. negative feedback by metabolites, BP ``` [external factor with feedback -> suckling on oxytocin positive feedback]

Answer 719

Usually caused by decrease in receptor in target tissue or antagonistic action, will lead to hypersecretion of hormone to compensate to normal physiological state by: 1) Negative feedback & receptor control e. g. decrease T4 receptor leads to decrease in T4 action; negative feedback increase in TRH receptor, thus increase T4 secretion for compensation

Answer 720

Peptide hormone binds to transcellular cell surface receptor, cell receptor activate coupling protein, which activates an effector protein for intracellular signal production -> hormonal effect

Answer 721

Cleaves Phosphatidylinositol 4,5- bisphosphate into DAG and IP3 (inositol 1,4,5 triphosphate); DAG activates PKC IP3 increases intracellular Ca++ from endoplasmic reticulum

Answer 722

By formation: ATP to cAMP by adenylyl cyclase By degradation: cAMP to AMP by phosphodiesterase

Answer 723

1) Peptide bind to receptor 2) Receptor Interacts with a G-protein 3) Dissociation of G-protein into the α and βγ-subunits 4) The α-subunit (From GDP to GTP-bound) activates effector proteins: adenylyl cyclase produces cAMP, phospholipase-C produces IP3 and DAG, and so on 5) In some cases, the βγ-subunits also activates phospholipase-C. 6) Hydrolysis of GTP to GDP by the intrinsic GTPase of the α-subunit disables the functional activity of the α-subunit 7) G protein reforms

Answer 724

1) Peptide binds to receptor 2) Receptor dimerisation 3) The tyrosine kinase of the cytosolic domain will self phosphorylate each other's cytosolic domain, as well as other proteins in the cytosol 4) Adaptor proteins connect added phosphate group with PLC, and other effector molecules like protein kinase and monomeric G-protein 5) Changes in activities of proteins in the cytosol, as well as expression of new genes in the nucleus bring about changes in cellular activities

Answer 725

1) GPCR are self limiting as internal GTPase activity of alpha subunit will dephosphorylate GTP to GDP, thus inactivating alpha subunit's stimulatory effect 2) Secondary signalling molecules are degraded e.g. cAMP to AMP by phosphodiesterase 3) By Dephosphorylation of phosphoproteins

Answer 726

cAMP activates cAPK; βγ subunits activate βARK cAPK and βARK phosphylate the peptide receptor to desensitise it, thus preventing further cAMP production and G protein activation cAPK: cAMP-dependent protein kinase βARK: a G-protein coupled receptor kinase (GRK)

Answer 727

By: 1) Receptor desensitisation by phosphorylation by cAPK and βARK 2) Receptor down-regulation by GRK-arrestin pathway 3) Receptor endocytosis

Answer 728

G-protein coupled receptor kinase (GRK) phosphorylate the GPCR β arrestin bind to phosphorylated GPCR internalisation of receptor by endocytosis (clathrin coated vesicle) to form endosome Receptors on endosome may be recycled

Answer 729

- Ecdysone, an insect steroid hormone, leads to puffing (decondensation) of bands of large polytene chromosome in insect salivary gland - Newly synthesized RNAs labelled by 3H-uridine localized to puffs => conclusion: DNA transcription is induced by steroid hormones

Answer 730

HRE for glucocorticoid receptor, alsosterone receptor, androgen receptor and progesterone receptor are the same HRE for Estrogen receptor is different

Answer 731

Steroid hormone pass through plasma membrane into cytoplasm some binds to cytoplasmic receptors -> conformational change to allow entry into nucleus some enter nucleus and bind to nuclear receptor -> Conformational change Receptor-ligand complex binds to HRE of the DNA, which controls transcription of the downstream sequence transcription of DNA, produce new proteins and give new physiological function

Answer 732

1) Variable region (N-terminal: vary in length, have unique sequences, and may contain one or more activation domains.) 2) DNA binding domain (central part; considerable sequence homology among different receptors) 3) Ligand binding domain (C-terminal; less homology)

Answer 733

Requires only the ligand-binding domain of the receptor and its extranuclear localization hormone bind to cytoplasmic receptor, activate protein kinase that will translocates into nucleus -> Control by direct phosphorylation (e.g. inactivating Bad) or activating transcription of some target genes via Elk-1/CREB

Answer 734

Cell growth (cell mass increase) -> mTOR mammalian target of rapamycin, a conserved kinas Cell proliferation (cell number increase) -> Cyclin-dependent kinase

Answer 735

For cell growth (cell mass increase) - transcription - translation - RNA processing - Protein stability - autophagy

Answer 736

Exercise increases AMPK level via ATP depletion -> help with growth regulation

Answer 737

- To counter cell production and maintain an appropriate number of cells in the tissues - eliminates unwanted structures during the development of the male and female inner reproductive organs - Remove interdigital mesoderm, initially formed between fingers - form intestinal lumen and other tissues

Answer 738

1) Protein synthesis regulated by the genes affected by the activated transcription factors => alteration of the relative abundance of pro-apoptotic and anti-apoptotic proteins 2) Release of apoptosis-inducing factor to change mitochondrial activity 3) Activation of the caspase cascade to breakdown DNA

Answer 739

- Contact inhibition

Answer 740

1) Human placenta prolactin 2) Peptide Growth factors: - Insulin, ILGF-1, ILGF-2 - Fibroblast growth factor FGF - Epidermal growth factor EGF - Transforming growth factor b (TGF beta) - platelet derived growth factor (PDGF)

Answer 741

Infancy: - Insulin, Insulin like GF-1, TH Childhoof: GH Puberty: Sex steroids

Answer 742

growth plate of bone

Answer 743

Outer to downwards - articular cartilage - secondary ossification centre - reserve cartilage (resting zone) - proliferating cartilage - hypertrophic cartilage - calcified cartilage

Answer 744

1) Stem cell giving rise to mesenchymal cell condensation, mesenchymal cell turning into osteochondro progenitor (sox 9), and then to chondrocyte (Sox 5, 6, 9) 2) Chondrocyte proliferation 3) Formation of pre-hypertrophic chondrocytes 4) Cessation of hypertrophic chondrocyte growth

Answer 745

- Ihh (indian hedgehog) - PTHrP - Fibroblast growth factor (FGF) - Vascular endothelial growth factor (VEGF) - Runx2 - transforming growth factor b (TGFb)

Answer 746

perichondrial cells and chondrocytes at the ends of long bones

Answer 747

acts on receptors on proliferating chondrocytes to keep the chondrocytes proliferating and, impair hypertrophic differentiation -> retard bone growth in endochondral ossification -> less prehypertrophic chondrocyte, thus decrease IHH productioin

Answer 748

1) acts on its receptor on chondrocytes to increase the rate of proliferation 2) stimulates the production of PTHrP at the ends of bones 3) perichondrial cells to convert these cells into osteoblasts of the bone collar

Answer 749

PTHrP secreted by perichondrial cells and chodrocyte at ends of long bone, prevent proliferating chondrocytes from entering hypertrophic differentiation (and decrease IHH here) As proliferating chodrocyte migrate further from bone end, PTHrP inhibition lifted, enters prehypertrophic differentiation and produce IHH; IHH increase proliferation rate, stimulate PTHrP production tan ends, and convert cells into osteoblasts -> the feedback loop regulates the relative proportion of proliferating and hypertrophic chodrocyte in growth plate

Answer 750

Prehypertrophic chondrocyte

Answer 751

FGFR1 - prehypertrophic and hypertrophic chondrocytes and perichondrium FGFR2 - perichondrium, periosteum and the primary spongiosa FGFR3 - proliferating chodrocyte

Answer 752

expressed in the perichondrium, actions are: FGFR3 - decrease chondrocyte proliferation FGFR1 - delay terminal differentiation of hypertrophic chondrocyte FGFR2 - delay osteoblast development and Decrease IHH expression

Answer 753

FGF 7, 8, 17, 18

Answer 754

- Increase chondrocyte proliferation - Accelerate terminal differentiation of hypertrophic chondrocyte - accelerate osteoblast development - Increase IHH expression

Answer 755

1) GH -> resting zone proliferation 2) IGF-1 -> resting and proliferative zone proliferation 3) Glucocorticoids -> inhibit proliferation, induce apoptosis 4) TH -> bone growth and proliferation 5) Estrogen -> inhibit proliferation 6) Androgen ->Stimulates proliferation 7) Vitamin D -> Permissive of hypertrophic zone normal physiology 8) Leptin -> proliferation

Answer 756

Hypothatlamus: Push-pull between GHRH, somatostatin Pituitary: GH Liver: IGF/ somatomedin Target: Growth

Answer 757

1) ↑ glucose uptake and ↓ lipolysis initially 2) somatomedin stimulate bone growth at epiphysis of long bones - increases deposition of protein by chondrocytic & osteogenic cells - increases the proliferation of chondrocytic & osteogenic cells - promotes conversion of chondrocytes into osteogenic cell

Answer 758

- Dimer VS monomer - Postnatal VS Foetal - mediates anabolic actions of both IGF-I and IGF-II VS bifunctional, serving both to target lysosomal enzymes and to enhance IGF-II turnover

Answer 759

GH -> transcription Estrogen -> mRNA expression T4

Answer 760

** Ultrasound ** Radionuclide scans (Plain XR) (CT - require iodine contrast) (MRI)

Answer 761

- Does not give extent of compression or displacement of trachea - Cannot evaluate other mediastinal structures

Answer 762

PROS: - No radiation and very convenient - Excellent for evaluating superficial structures such as the thyroid gland - excellent spatial resolution (Sensitive in detecting tiny nodule) - can identify calcification CONS: Unable to differentiate accurately between benign and malignancy; SENSITIVE BUT NOT SPECIFIC

Answer 763

SENSITIVE BUT UNSPECIFIC, always use US guided FNAC or fine needle biopsy 1) Solid VS cystic, size, number 2) vascularity using colour doppler US (e.g. increased in Grave's or papillary adenoma) 3) Microcalcifications (psammoma bodies) commonly in papillary carcinoma (or follicular or anaplastic) 4) Coarse calcification (medullary carcinoma) 5) Hypoechoic (darker -> more likely malignant) 6) Margin/Contour - Ill-defined/Irregular margin

Answer 764

Fine needle aspirate cytology Major drawback: cannot distinguish follicular adenoma or carcinoma -> need biopsy for histology (Rely on capsular or venous invasion)

Answer 765

FUNCTIONAL INFORMATION: 99m-Tc pertechnetate VS Iodide scan Trapped by thyroid VS trapped by thyroid Not organified VS Organified (incorporated into thyroglobulin)

Answer 766

Use I-123 or I-131, both trapped and organised

Answer 767

Assess metabolic function - Hot (increased intake) - Cold (no intake) Shows position of ectopic thyroid gland

Answer 768

HOT - excludes cancer - primary hyperthyroidism e.g. Multinodular goitre - iodine deficiency COLD - majority benign lesion (colloid nodule, thyroiditis, adenoma) - all cancers are cold (CA thyroid, lymphoma) => always of needle biopsy

Answer 769

- Cross-sectional anatomy, to evaluate local and distal extent of disease - When there's an Intrathoracic extension of goitre - Post surgical or radioactive treatment surveillance for recurrence

Answer 770

regulated at the level of synthesis rather than secretion - > steroidogenic cells don't store steroids - > freely diffuse out of membrane due to lipophilic nature; no exocytosis

Answer 771

drugs and carcinogens or endogenous compounds like steroid hormones, bile acids, prostaglandins

Answer 772

Cyto -> in mitochrondria and microsomes (endoplasmic reticulum)

Answer 773

Monooxygenases or hydroxylases: RH + O2 + NADPH + [H+] => ROH + H2O + [NADP+]

Answer 774

Cholesterol to pregnenolone by CYP11A (stimulated by ACTH)

Answer 775

Mitochondrial, in all primary steroidogenic tissues (adrenal cortex, ovary, placenta, Leydig cells) - required for aldosterone, cortisol and androgen production RATE LIMITING and stimulated by ACTH

Answer 776

Microsomal, in all primary steroidogenic tissues (adrenal cortex, ovary, placenta, Leydig cells) and skin, liver, prostate, breast - required for aldosterone, cortisol and androgen production

Answer 777

Microsomal, adrenal cortex's zona fasciculata and reticularis - required for androgen and cortisol production (NOT aldosterone)

Answer 778

Microsomal, in adrenal cortex - required for aldosterone and cortisol production

Answer 779

Mitochondrial, in adrenal cortex (11B1 in fasciculata; 11B2 in glomerulosa) - 11B1 for cortisol production; 11B2 for aldosterone production

Answer 780

Directly by by ACTH (increased in stress or morning) Aldosterone: 1) Renin‐angiotensin‐aldosterone system 2) [K+] (more K increase production) 3) ANP (decrease production) 4) Minimally from ACTH

Answer 781

1) deliberate actions eg needle threading is guided in real time by moment to moment correction via sensory feedback 2) ballistic movements are too fast for sensory guidance and are orchestrated by cerebellum based on previous experience eg golf swing

Answer 782

Zygomatic process of maxilla Zygomatic bone Zygomatic process of temporal bone

Answer 783

Superior: anterior mandible, posteriorly base of cranium Inferior: sternum, clavicle, acromion, C7 spinous process

Answer 784

1) Superficial fascia - subcutaneous connecting skin to deep fascia - contains platysma, superficial veins DEEP FASCIA 2) deep investing layer - covers sternocleidomastoid and trapezius 3) pretracheal layer - visceral compartment - larynx, pharynx, trachea, esophagus, thyroid thymus parathyroid 4) Prevertebral layer - vertebral compartment - cervical spine and spine muscles 5) carotid sheath - vascular compartment - common carotid artery, IJV, CN X

Answer 785

Upper: lower border of mandible Lower: SCM anterior border Medial: midline Content: trachea, esophagus Muscles connected to hyoid ie Omohyoid geniohyoid thyrohyoid sternohyoid sternothyroid Thyroid and parathyroids

Answer 786

``` Apex: back of skull Anterior: SCM posterior border Posterior: Trapezius anterior border Base: middle of clavicle Roof: deep investing fascia Floor: flexor and extensor of cervical spine ``` ``` Contents: Omohyoid Subclavian artery (suprascapular, dorsal scapular, occipital) EJV CN XI Branchial plexus ```

Answer 787

Upper: mandible lower border Lower: anterior and posterior belly of digastric Floor: mylohyoid and hyoglossus Content: Submandibular gland Submandibular lymph nodes Deep cervical lymph nodes External and internal carotid artery IJV CN X, XII

Answer 788

Boundary: anterior belly of digastric, midline, hyoid bone Floor: mylohyoid Contents: Submental nodes Anterior jugular vein

Answer 789

Boundary: anterior border SCM, posterior belly of digastric, stylohyoid, upper belly of omohyoid Floor: thyrohyoid, hyoglossus, pharynx Contents: common carotid artery dividing IJV CN X, XI, XII Deep cervical lymph nodes

Answer 790

Boundary: midline, hyoid, upper belly of Omohyoid, SCM floor: sternothyroid, sternohyoid Contents: - trachea, esophagus, larynx - thyroid gland

Answer 791

Superficial part in submandibular fossa Deep part in floor of mouth Submandibular from anterior deep part run between genioglossus and sublingual gland to sublingual papilla - > associated with facial artery, common facial vein and facial nerve's mandibular branch - > supply by chorda tympani from submandibular ganglion

Answer 792

Between mylohyoid and genioglossus Supplied by chorda tympani from submandibular ganglion

Answer 793

``` Superficial: SHLS submandibular duct Hypoglossal nerve CN XII Stylohyoid muscle Lingual nerve (V3) ``` Deep: Glossopharyngeal nerve CN IX Stylohyoid ligament Lingual artery

Answer 794

Wedged between mandibular ramus and mastoid process of temporal bone

Answer 795

Parotid papilla which is opposite to upper second molar

Answer 796

Memory | Emotion and behaviours

Answer 797

- defence and attack, fear, rage | - influence hypothalamus' endocrine

Answer 798

EXPLICIT MEMORY - events (episodic) and facts (semantic): hippocampus, nucleus basalis, medial temporal lobe IMPLICIT MEMORY: - skills and habits: striatum, cerebellum, cortex motor area - emotional: amygdala, insula - conditioned reflex: cerebellum WORKING MEMORY: Spatial: dorsolateral prefrontal cortex Non-spatial: ventrolateral prefrontal cortex

Answer 799

Fear, anxiety Stimulates affective aggression (medial hypothalamus) Inhibits predatory aggression (lateral hypothalamus)

Answer 800

1) hypothalamus for sympathetic activation of flight or fight 2) reticular formation for arousal 3) brain stem nuclei for emotional behaviours like facial expression

Answer 801

Learning, recent memory (lesion lead to anterograde amnesia) Memory

Answer 802

Membrane permeability Nuclear regulation Protein synthesis control Enzyme activation