Visceral systems

Question 1

structural division of respiratory system

Answer 1

1) upper: nasal cavity, nose, pharynx, larynx
2) lower: trachea, bronchi, bronchioles

Question 2

functional division of respiratory system

Answer 2

1) conducting: nasal cavity, pharynx, larynx, trachea, bronchi, terminal bronchioles
2) respiratory: respiratory bronchioles, alveolar ducts, alveoli

Question 3

conducting portion features

Answer 3

• lined by respiratory mucosa
• function: filter, warm and moisten air

Question 4

respiratory mucosa

Answer 4

1) pseudostratified ciliated (motile to sweep mucus and trapped contaminants towards pharynx for swallowing or expulsion) columnar epithelium with goblet cells (produce mucus) + stem cells
2) lamina propria: loose CT with BVs to warm air + mucous glands

Question 5

respiratory portion features

Answer 5

• respiratory bronchiole branches from terminal bronchiole, then into alveolar ducts that lead into alveolar sac (made up of alveoli)
• function: where gas exchange takes place

Question 6

nasal cavity features

Answer 6

• extends anteriorly from nares (nostrils) to choanae posteriorly (continuous with nasopharynx)
• functions: conduct air, filter/warm/humidify air, sense odorants

Question 7

nasal septum

Answer 7

• divides nose into left and right parts
• formed by perpendicular plate of ethmoid and vomer

Question 8

nasal cavity subdivision

Answer 8

• superior, middle and inferior conchae separate cavity into air passages (meatuses)
• curved shape keeps air in cavity for longer (swirling around)
• sinuses also connect with nasal cavity
• everything surrounded by mucosa

Question 9

lateral wall of nasal cavity

Answer 9

• superior and middle nasal conchae (ethmoid)
• lacrimal bone
• inferior nasal concha
• maxilla
• perpendicular plate of palatine

Question 10

medial wall of nasal cavity

Answer 10

• nasal septum: perpendicular plate of ethmoid, vomer and septal cartilage (hyaline)

Question 11

roof of nasal cavity

Answer 11

• cribriform plate of ethmoid
• frontal bone
• nasal bone
• sphenoid bone

Question 12

floor of nasal cavity

Answer 12

• horizonal plate of palatine
• palatine process of maxilla

Question 13

paranasal sinuses

Answer 13

• lighten mass of skull, increase surface area of respiratory mucosa, create turbulence
• communicate with cavity via ducts

Question 14

paranasal sinus ducts

Answer 14

1) above superior meatus: sphenoidal sinus
2) into superior meatus: posterior ethmoidal air cells
3) into middle meatus: frontal sinus, maxillary sinus
4) into inferior meatus: nasolacrimal duct

Question 15

olfaction

Answer 15

• superior part of nasal cavity has olfactory epithelium
• turbulence brings odorants into contact with epithelium, where they dissolve in mucus and stimulate sensory neurons (binding to specific receptors = depolarization)

Question 16

olfactory organs

Answer 16

1) olfactory epithelium: specialized pseudostratified ciliated columnar
2) underlying lamina propria

Question 17

cells of olfactory epithelium

Answer 17

1) olfactory sensory neurons: bipolar, dendrites form knob that projects into nasal cavity
2) supporting cells: mechanical and metabolic support to receptor cells
3) basal cells: replace olfactory sensory neurons, decrease with age

Question 18

olfactory knob

Answer 18

• contains non-motile cilia with olfactory receptors on the surface

Question 19

olfactory pathway

Answer 19

two neurons:
1) from olfactory epithelium, form CN I and pass through cribriform plate
2) in olfactory bulb, travel in olfactory tract to primary olfactory cortex (temporal lobe), hypothalamus, and limbic system
*thalamus not involved! only exception out of the senses

Question 20

oral cavity function

Answer 20

• analysis of food
• mechanical processing
• lubrication (saliva)
• limited digestion

Question 21

oral cavity characteristics

Answer 21

• lined by oral mucosa: stratified squamous non-keratinized epithelium
• buccal fat pads and buccinator muscles support mucosa of cheeks

Question 22

oral cavity features

Answer 22

1) hard and soft palate
2) palatoglossal arch: extends directly from uvula
3) palatopharyngeal arch: posterior to 2)
4) palatine tonsil: between arches
5) uvula: extends from soft palate
6) superior labial, lingual, inferior labial frenulum
7) fauces: opening to pharynx
8) oral vestibule: space between cheek/lips and teeth
9) gingiva: gums

Question 23

oral cavity boundaries

Answer 23

1) roof: hard (maxilla and palatine) and soft palate
2) floor: tongue
3) anterior: teeth and lips with orbicularis orbis
4) posterior: palatoglossal arch/folds, palatine tonsil, palatopharyngeal arch/golds

Question 24

orbicularis orbis

Answer 24

• sphincter muscle continuous around the mouth

Question 25

soft palate function

Answer 25

- moves up to close off nasopharynx during swallowing

Question 26

uvula function

Answer 26

- prevents food from entering oropharynx too soon

Question 27

tongue muscles

Answer 27

1) extrinsic: pass to tongue from bony attachments (to external structures), function to position tongue for speech and swallowing 2) intrinsic: divided by left and right halves by median sagittal septum, within tongue in different orientations, function to alter shape of tongue

Question 28

extrinsic tongue muscles

Answer 28

1) hyoglossus (3): attach to hyoid bone 2) palatoglossus: palatine 3) genioglossus: chin (genu of mandible) 4) styloglossus: styloid process of temporal bone

Question 29

innervation of tongue

Answer 29

1) motor: majority by CN XII, palatoglossus by CN X 2) posterior tongue: general sensory and special (taste) by CN IX 3) anterior tongue: special by CN VII and general by CN V3

Question 30

CN XII lesion

Answer 30

- dysarthria: difficulty speaking - dysphagia: difficulty swallowing

Question 31

floor of the mouth

Answer 31

- mandible - hyoid - suprahyoid muscles - salivary glands

Question 32

suprahyoid muscles

Answer 32

- elevate hyoid and larynx when swallowing 1) digastric (anterior belly, "two bellies") 2) stylohyoid (styloid process 3) mylohyoid (mandible) 4) geniohyoid (chin)

Question 33

infrahyoid muscles

Answer 33

- below hyoid - not part of floor of mouth 1) omohyoid: scapula to hyoid 2) sternohyoid: sternum to hyoid 3) sternothyroid: sternum to thyroid cartilage 4) thyrohyoid: thyroid cartilage to hyoid

Question 34

salivary glands

Answer 34

- three pairs: parotid, sublingual, submandibular - multicellular exocrine - enclosed by dense fibrous CT - produce/secrete saliva under autonomic control

Question 35

parotid gland

Answer 35

- duct opens into oral vestibule (by second maxillary molar) - largest salivary gland

Question 36

sublingual gland

Answer 36

- below tongue - numerous ducts open into floor of oral cavity (lateral to that of submandibular gland)

Question 37

submandibular gland

Answer 37

- below mandible - ducts open into floor of oral cavity lateral to lingual frenulum

Question 38

temporomandibular joint (TMJ)

Answer 38

- synovial joint - mandibular fossa (temporal bone) articulates with head of condylar process (mandible) - articular surfaces separated by fibrocartilage disc - loose capsule = highly mobile and easily dislocated

Question 39

TMJ movements

Answer 39

1) hinge: elevation (close mouth) and depression (open mouth) 2) gliding: retraction (tuck chin), protrusion/protraction (stick chin out), lateral grinding

Question 40

lockjaw

Answer 40

- dislocated TMJ - jaw stuck open

Question 41

muscles of mastication

Answer 41

- produce TMJ movements - innervated by CN V3 1) temporalis: elevation and retraction 2) masseter: elevation 3) lateral pterygoid: protrusion, side to side movement, opening jaw (mostly by gravity) 4) medial pterygoid: elevation, side to side movement

Question 42

pterygoid muscle attachments

Answer 42

- to lateral pterygoid plate

Question 43

pharynx

Answer 43

- common space used by respiratory and digestive systems - muscular tube extending from base of skull to upper esophageal sphincter - contracts reflexively during swallowing - stratified squamous nonkeratinized

Question 44

pharynx innervation

Answer 44

- motor: CN X - sensory: CN IX

Question 45

pharynx parts

Answer 45

1) nasopharynx: pharyngeal tonsils (adenoids), opening of pharyngotympanic tubes (connection to auditory tube) 2) oropharynx: palatine and lingual tonsils, first line of defense 3) laryngopharynx: opens into larynx (air) and esophagus (food)

Question 46

cricoid caritlage

Answer 46

forms part of larynx (laryngopharynx)

Question 47

pharyngeal muscles

Answer 47

1) circular: constrict during swallowing (ordered), overlap each other - superior, middle and inferior pharyngeal constrictor 2) longitudinal: - stylopharyngeus (styloid process) - palatopharyngeus (soft palate) - salpingopharyngeus (pharyngotympanic tube)

Question 48

pharyngeal muscle innervation

Answer 48

- CN X for all except stylopharyngeus (CN IX)

Question 49

larynx features

Answer 49

- laryngopharynx opens anterior into larynx and posteriorly to esophagus - inferiorly into trachea - function: passage of air, vocalization and prevents food from entering trachea (epiglottis covers larynx)

Question 50

larynx hyoid connection

Answer 50

- suspended from hyoid bone by thyrohyoid membrane

Question 51

extrinsic muscles of larynx

Answer 51

- suprahyoid: elevate hyoid bone (and larynx) - infrahyoid: depress - during swallowing and speaking - specifically during swallowing: elevated larynx bends epiglottis over laryngeal inlet

Question 52

larynx cartilage

Answer 52

- held in place by ligaments and muscles - three unpaired frameworks: 1) thyroid cartilage: anterior laryngeal prominence ("adam's apple"), incomplete posteriorly (superior and inferior horn) 2) cricoid cartilage: complete ring, inferior to 1) 3) epiglottis - paired: 1) arytenoid cartilages: associated with corniculate and cuneiform cartilages

Question 53

larynx cartilage connecting membranes

Answer 53

1) thyrohyoid membrane: dense CT connecting larynx to hyoid 2) cricothyroid membrane: connects thyroid and cricoid cartilage

Question 54

larynx intrinsic ligaments

Answer 54

- not the same as bone-bone ligaments - extend between cartilage 1) vestibular ligament: corniculate and thyroid cartilage, along with mucosa forms vestibular folds to protect vocal folds 2) vocal ligament: arytenoid and thyroid, elastic CT, along with mucosa forms vocal folds (avascular, produce sound)

Question 55

rima glottidis

Answer 55

space between vocal folds

Question 56

epithelium in the larynx

Answer 56

- above vocal folds: stratified squamous nonkeratinized - below: respiratory epithelium

Question 57

sound production (phonation)

Answer 57

- adductor intrinsic muscles adduct arytenoid cartilages - rima glottidis decreases in size --> air passing through vibrates folds to produce sound waves

Question 58

vocal folds during respiration

Answer 58

- abductors abduct arytenoid cartilages

Question 59

tensors and relaxers

Answer 59

- tiny muscles that adjust length of vocal ligaments by tilting thyroid cartilage

Question 60

what affects sound production?

Answer 60

1) tone: approximation of vocal folds 2) pitch: anterior rocking of thyroid = more tension in vocal fold = higher pitch 3) volume: more air = more speed = louder voice 4) quality: vibration within larynx, pharynx, oral cavity, nasal cavity and nasal sinuses

Question 61

what happens in whispering?

Answer 61

- arytenoids are adducted, but not fully pulled medially - all but posterior portion of rima glottidis closed - more air passes through, vocal folds don't vibrate as much and thus quieter pitch

Question 62

thoracic cavity location

Answer 62

above diaphragm

Question 63

abdominopelvic cavity location

Answer 63

below diaphragm

Question 64

characteristics of body cavities

Answer 64

- lined by serous membranes - do not open to the exterior

Question 65

serous membrane layers

Answer 65

1) visceral layer: around organ 2) parietal layer - layers are continuous with each other - layers produce serous fluid (lubricant) that fills serous cavity between them

Question 66

thoracic cavity subdivision

Answer 66

1) mediastinum: between pleural cavities, includes pericardial cavity with heart 2) right pleural cavity: right lung 3) left pleural cavity: left lung

Question 67

mediastinum

Answer 67

- sternum anterior, thoracic vertebrae posterior - bordered laterally by lungs - further divisions: 1) posterior mediastinum: trachea, primary bronchi, esophagus, great vessels, loose areolar CT 2) middle mediastinum: contains heart 3) anterior mediastinum

Question 68

tracheal rings

Answer 68

- trachea surrounded by 15-20 tracheal rings (anterior, c-shaped) and muscle (posterior, in front of esophagus)

Question 69

annular ligaments

Answer 69

- join tracheal rings - elastic cartilage allows for flexibility

Question 70

carina of trachea

Answer 70

- bifurcation of trachea into right and left primary bronchi

Question 71

branching of bronchial tree

Answer 71

1) trachea 2) primary bronchi: enter hilus of each lung, one per lung 3) lobar (secondary) bronchi: one per lung lobe 4) segmental (tertiary) bronchi: one per bronchopulmonary segment 5) bronchioles: each tertiary branches several times to form these 6) terminal bronchioles

Question 72

trachea structure

Answer 72

- connects larynx to primary bronchi - lined with respiratory mucosa - cartilage rings anteriorly - trachealis muscle (smooth) posteriorly: relaxes with SyNS stimulation for bronchodilation

Question 73

layers of trachea epithelium

Answer 73

1) respiratory epithelium (mucosa) 2) lamina propria (mucosa) 3) seromucous glands in submucosa 4) perichondrium 5) hyaline cartilage ring

Question 74

right/left lung lobes

Answer 74

- right = superior, middle and inferior - left = superior and inferior

Question 75

bronchopulmonary segments

Answer 75

- 9-10 in each lung - each has tertiary bronchus

Question 76

benefit of lung segmentation

Answer 76

- diseased segments can be removed while preserving function of others

Question 77

bronchi histology

Answer 77

- respiratory mucosa with fewer goblet cells - amount of cartilage decreases moving through bronchi (inhibit gas exchange) - circular layer of smooth muscle appears in bronchi (can change size of tube, modulates SA) - lots of lymphocytes

Question 78

bronchiole histology

Answer 78

- epithelium becomes simple ciliated columnar/cuboidal, then simple cuboidal/low columnar (bronchiolar exocrine aka club cells) - no mucosal glands or cartilage - smaller, less circular lumen than bronchi - more smooth muscle (prominent bundles lead to distinct shape) - adjacent to blood vessels - surrounded by alveoli - lots of lymphocytes

Question 79

respiratory portion branching

Answer 79

1) respiratory bronchioles: from terminal bronchioles, decreasing smooth muscle 2) alveolar ducts: no smooth muscle 3) alveolar sac: collections of alveoli 4) alveoli

Question 80

pulmonary lobule

Answer 80

- branches of pulmonary arteries form capillary beds around alveoli for gas exchange - pulmonary artery -> pulmonary arteriole -> pulmonary venules -> pulmonary vein -> heart

Question 81

respiratory bronchiole histology

Answer 81

- lined with bronchiolar exocrine cells - surrounded by few alveoli - subdivide into alveolar ducts with simple squamous epithelium - pulmonary arteries and veins visible

Question 82

alveoli characteristics

Answer 82

- site of gas exchange, resembles a pouch (open on one side to alveolar duct/sac) - between alveoli: interalveolar septa with fibroblasts, elastic (spongy) and reticular (maintain shape) fibers + pulmonary capillaries - two types of cells (pneumocytes) and macrophages

Question 83

type I alveolar cells

Answer 83

- numerous - form simple squamous epithelium

Question 84

type II alveolar cells

Answer 84

- rounded cells, vacuolated cytoplasm - not as numerous - secrete surface-active agent (surfactant) to decrease surface tension and maintain alveolar patency (sacs remain open)

Question 85

alveolar macrophage

Answer 85

- phagocytose particulate matter - contribute to black remnants on lungs (some in healthy, lots in smoker lungs)

Question 86

blood-air barrier

Answer 86

- respiratory membrane with: 1) endothelium 2) thin basement membrane 3) alveolar epithelium - gas exchange is rapid due to thinness (~0.5 micrometer) of membrane and small, lipid-solubility of gases

Question 87

alveoli histology

Answer 87

- lots of empty space - type I cells: flat, little cytoplasm - type II: cuboidal/round - macrophages: darker spots, protrude into spaces - capillaries: contain RBCs

Question 88

emphysema

Answer 88

- damaged and permanently enlarged alveoli (destruction of elastic fibers in lungs) - breathlessness because air becomes trapped in lungs at the end of exhalation (can't push out, gas exchange inhibited as well)

Question 89

respiratory epithelium proximal to distal

Answer 89

1) trachea: pseudostratified ciliated columnar with goblet cells 2) bronchi: transition to simple columnar with cilia and few goblet cells 3) bronchioles: transition to simple cuboidal with or without cilia, exocrine cells appear as they branch 4) alveoli: type I/II alveolar cells

Question 90

respiratory lamina propria proximal to distal

Answer 90

1) trachea: loose CT 2) bronchi: loose CT 3) bronchioles: thin or indistinct 4) alveoli: none

Question 91

respiratory secretory cells proximal to distal

Answer 91

1) trachea: seromucous glands in submucosa 2) bronchi: seromucous glands in submucosa 3) bronchioles: bronchiolar exocrine cells 4) alveoli: type II alveolar cells

Question 92

respiratory cartilage rings proximal to distal

Answer 92

1) trachea: c-shaped, joined by annular ligaments 2) bronchi: incomplete, irregular plates 3) bronchioles: none 4) alveoli: none

Question 93

respiratory smooth muscle proximal to distal

Answer 93

1) trachea: trachealis (at free ends of cartilage) 2) bronchi: discontinuous layer, more prominent as bronchi branch 3) bronchioles: prominent, large layer --> thin, indistinct, small layer 4) alveoli: none

Question 94

respiratory adventitia proximal to distal

Answer 94

1) trachea: loose CT 2) bronchi: loose CT 3) bronchioles: merges with submucosa 4) alveoli: none

Question 95

pleura

Answer 95

- serous membrane lining wall of pleural cavity and lungs - mesothelium: simple squamous epithelium attached to loose areolar CT - layers: parietal pleura, pleural cavity (small, with pleural fluid), visceral pleural

Question 96

pleural cavity

Answer 96

- contains transudate (pleural fluid) for lubrication and tension between membranes

Question 97

pleural recesses

Answer 97

- spaces left behind in pleural cavity to accommodate expansion of lungs during inhalation 1) costodiaphragmatic recess: around costal edge of base of lung 2) costomediastinal recess: extension of cavity between sternum and mediastinum

Question 98

pleural effusion

Answer 98

- excess fluid in pleural space, shows up as white on x-ray instead of black (empty air) - two types: 1) transudative pleural effusion: caused by changes in hydrostatic pressure, leads to excess fluid 2) exudative pleural effusion: inflammatory conditions, infection, lung injury or tumour, leads to excess fluid, protein and immune cells --> additional spaces in endothelial cells

Question 99

lung structure

Answer 99

- cone shape with apex above clavicle and base - lobes separated by deep fissures - right lung: superior, middle, inferior lobe - left lung: superior, inferior

Question 100

lung lobe surfaces

Answer 100

1) costal: contact with ribs (anterior, lateral and posterior) 2) mediastinal: medial surface 3) diaphragmatic: base, close to diaphragm

Question 101

lung fissures

Answer 101

1) horizontal: separates superior and middle (right lung) 2) oblique: separates middle and inferior (right) or superior and inferior (left)

Question 102

root of the lung

Answer 102

- contained in the hilus - consists of primary bronchi, pulmonary arteries, veins, nerves and lymphatics enclosed in CT

Question 103

hilus arrangement in R/L lung

Answer 103

- right: veins inferior, arteries anterior to primary bronchi - left: artery most superior, primary bronchus, veins inferior to other two

Question 104

grooves and impressions in lung

Answer 104

- right: posterior esophageal impression - left: posterior groove for aorta, anterior cardiac impression and cardiac notch

Question 105

thorax bones

Answer 105

- 12 pairs of ribs (flat bones) and costal cartilages - 12 thoracic vertebrae and intervertebral disks - sternum

Question 106

sternum structure

Answer 106

1) manubrium: articulates with clavicles 2) body 3) xiphoid process

Question 107

intercostal space

Answer 107

between ribs

Question 108

costal margin

Answer 108

formed by bottom of rib cage

Question 109

types of ribs

Answer 109

1) true ribs (1-7): attach directly to sternum via a costal cartilage 2) false ribs (8-12): attach indirectly (not their own costal cartilage to sternum OR lack attachment 3) (false) floating ribs (11-12): no anterior attachment or tubercular facets

Question 110

typical rib structure

Answer 110

1) head: has two articular facets that articulate with body of thoracic vertebrae 2) neck 3) tubercle: has tubercular facet to articulate with transverse process of thoracic vertebra (corresponding) 4) angle 5) costal groove: internal aspect, protects blood vessels and nerves 5) body 6) costal cartilage (for most) *applies to ribs 3-9

Question 111

what permits movement of thoracic wall?

Answer 111

articulations of ribs and thoracic vertebrae (synovial joints)

Question 112

superior/inferior thoracic aperture

Answer 112

- superior: bordered by T1, 1st ribs and superior border of manubrium + contains trachea and blood vessels - inferior: bordered by T12, ribs 11/12, costal margins and xiphisternal joint + closed off by diaphragm

Question 113

attachments of rib cage

Answer 113

1) jugular notch 2) clavicular notch: clavicle 3) sternal angle: manubrium and body articulate, forms protrusion 4) costal notches: attachment of costal cartilage 5) xiphisternal joint: body and xiphoid process articulate, has limited movement 6) diaphragm attachment

Question 114

thoracic wall muscles

Answer 114

- occupy and support intercostal spaces - overlap each other and fibers run in different directions for added strength 1) external intercostals: do not attach to sternum, fibers run inferiorly and anteriorly, elevate ribs during inhalation 2) internal intercostals: start from sternum, fibers run inferiorly and posteriorly, depress ribs during FORCED exhalation 3) innermost intercostals

Question 115

costal groove

Answer 115

- contains VAN (vein, artery, nerve --> superior to inferior) - between inner and innermost intercostals

Question 116

arteries of thoracic wall

Answer 116

1) thoracic aorta 2) subclavian artery (branches off brachiocephalic) 3) internal thoracic arteries: anterior aspect inside thoracic wall, arises from 1) 4) anterior and posterior intercostal arteries: from 1) and 3), in costal groove, ant/pos anastomose with each other for collateral circulation 5) subcostal artery (last artery)

Question 117

veins of thoracic wall

Answer 117

1) internal thoracic vein: drains blood anteriorly into brachiocephalic vein and superior vena caba 2) anterior and posterior intercostal veins: most (posterior) drain into azygos venous system 3) subcostal vein 4) azygos and hemiazygos veins: drain back and thoracoabdominal walls and viscera, pathway between SVC and IVC

Question 118

azygos venous system

Answer 118

1) right intercostal veins drain into azygos 2) left intercostal veins drain into hemiazygos, then azygos 3) azygos drains into superior vena cava

Question 119

lymphatic drainage in thoracic wall

Answer 119

- lymphatics throughout drain thoracic wall into thoracic duct

Question 120

inhalation mechanism

Answer 120

- thoracic cavity dimensions and intrathoracic volume increases - draws air in because of pressure drop - structure of pleura and lungs enable this to occur: pleural fluid creates tension between membranes, inherent elasticity of lungs allow expansion to remain in contact with thoracic wall - diaphragm contracts (flattens)

Question 121

exhalation mechanism

Answer 121

- typically passive process: recoil of lungs and relaxation of muscles - intrathoracic volume decreases, expelling air out

Question 122

movements of thoracic wall during inhalation

Answer 122

- diaphragm (flattens) and external intercostals (elevates ribs and sternum) contract - vertical changes: diaphragm flattens - lateral changes: ribs elevated, thoracic cavity widens - anterior/posterior changes: inferior portion of sternum moves anteriorly

Question 123

movements of thoracic wall during exhalation

Answer 123

- passive process - vertical changes: diaphragm relaxes, moves up, thoracic cavity narrows - lateral changes: ribs depressed, thoracic cavity narrows - anterior-posterior changes: inferior portion of sternum moves posteriorly

Question 124

diaphragm structure

Answer 124

- forms floor of thoracic cavity - muscle fibers arranged radially and insert into central tendon - space for inferior vena cava, esophagus and aorta (posterior) - crura: attach diaphragm to lumbar vertebrae

Question 125

diaphragm action and innervation

Answer 125

- contraction increases vertical dimension of thoracic cavity - innervated by phrenic nerves (C3-C5)

Question 126

structures that pass through diaphragm

Answer 126

1) internal vena cava: between right dome and pericardial sac 2) esophagus: behind pericardial sac, in front of thoracic vertebra 3) aorta: between thoracic vertebra and left dome

Question 127

accessory muscles of respiration

Answer 127

- attached to thoracic wall and could be involved in breathing

Question 128

neural control of respiration

Answer 128

- rate/depth of breathing matched with tissue oxygen and CO2 removal demands - controlled by brainstem nuclei (pons and medulla) 1) posterior respiratory group (medulla): efferent fibers control inspiration 2) anterior respiratory group (medulla): efferent fibers coordinate innervation of both inspiratory and expiratory muscles 3) CN IX/X (to medulla): modulate feedback based on input from baroreceptors and chemoreceptors 4) pontine respiratory group: receives higher level input (cerebral cortex, limbic system, hypothalamus), outputs to medulla to adjust respiratory pace --> some voluntary control

Question 129

heart as a double pump

Answer 129

- right side: conveys blood through pulmonary circuit - left side: conveys blood through systemic circuit - both sides at the same time

Question 130

arteries vs veins

Answer 130

arteries carry blood away from heart, veins towards heart

Question 131

heart chambers

Answer 131

two atria superior to two ventricles

Question 132

heart position

Answer 132

- left of midline in middle mediastinum - oblique angle to longitudinal axis of body (slightly rotated to left)

Question 133

heart shape

Answer 133

- base of heart = posterior surface - apex located in 5th intercostal space

Question 134

pericardium

Answer 134

- surrounds heart and roots of the great vessels - two parts: outer fibrous pericardium and inner serous pericardium (two layers) - function: stabilize position of heart and prevents overfilling (bc attached to other structures, ex. fibrous attached to diaphragm)

Question 135

serous pericardium

Answer 135

1) visceral layer: attaches to heart - potential space (pericardial cavity) containing pericardial fluid (lubrication) between layers 2) parietal layer: attaches to fibrous pericardium

Question 136

components of heart wall

Answer 136

superficial to deep: (parietal layer of serous pericardium: mesothelium, areolar CT and pericardial cavity) 1) epicardium (visceral layer of serous pericardium): mesothelium and areolar CT 2) myocardium: cardiac muscle tissue 3) endocardium: unique endothelium and areolar CT

Question 137

heart surfaces

Answer 137

1) right pulmonary surface: formed by right atrium 2) anterior surface: majority right ventricle 3) left pulmonary surface: left ventricle 4) diaphragmatic surface

Question 138

external heart sulci

Answer 138

1) coronary sulcus: between atria and ventricles, location of fibrous skeleton 2) anterior/posterior interventricular sulci: between ventricles, overlie interventricular septum

Question 139

anterior external heart

Answer 139

1) right atrium 2) right auricle (flap) 3) right ventricle 4) left ventricle 5) left auricle * cannot see left atrium

Question 140

posterior external heart

Answer 140

1) left atrium 2) right atrium 3) left ventricle 4) right ventricle

Question 141

right heart input/output

Answer 141

input: deoxygenated blood to right atrium 1) superior vena cava: drains head and upper limbs 2) inferior vena cava: below diaphragm 3) coronary sinus: heart wall output: from right ventricle 1) pulmonary trunk 2) continues to right and left pulmonary arteries --> lungs

Question 142

left heart input/output

Answer 142

input: oxygenated blood to left atrium 1) right and left pulmonary veins (two on each side) output: from left ventricle 1) ascending aorta 2) aortic arch 3) descending aorta

Question 143

heart borders

Answer 143

1) right border: right atrium 2) left border: left ventricle 3) inferior border: mostly right ventricle, a little left ventricle

Question 144

internal right atrium

Answer 144

1) input vessels: SVC, IVC, coronary sinus 2) interatrial septum 3) fossa ovalis: remnant of embryonic foramen ovale 4) pectinate muscles: create rough wall 5) crista terminalis: line dividing smooth and rough parts of atrium

Question 145

embryonic foramen ovale

Answer 145

- direct connection between right and left atrium - no need for pulmonary circulation as an embryo

Question 146

internal right ventricle

Answer 146

1) right atrioventricular valve (tricuspid) cusps (3) 2) septomarginal trabecula: extend from septum, attach to papillary muscles and trabeculae carnea 3) pulmonary semilunar valve cusps 4) conus arteriosus

Question 147

atrioventricular valve structures

Answer 147

1) cusps attach to chordae tendineae 2) attach to papillary muscles 3) trabeculae carneae: rough inner wall (no smooth parts in ventricle)

Question 148

atrioventricular valve cusp function

Answer 148

- like a parachute: chordae tendinae are strings attached to the papillary muscle (person) --> prevent cusps from everting - cusp pulled taut in a curved shape

Question 149

semilunar valve cusp function

Answer 149

- curved shape causes blood to pool in the closed cusps

Question 150

internal left atrium

Answer 150

1) left atrioventricular valve (bicuspid or mitral) cusps (two) 2) interatrial septum: smooth wall 3) left auricle: lined with pectinate muscles (rough)

Question 151

internal left ventricle

Answer 151

1) aortic semilunar valve cusps

Question 152

aorta vs pulmonary trunk

Answer 152

aorta has openings of coronary arteries early on (oxygenated blood goes to heart first)

Question 153

why is LV wall thicker than RV?

Answer 153

- higher force needed to pump to entire body, not just lungs

Question 154

valve primary function

Answer 154

- ensure unidirectional flow of blood

Question 155

fibrous skeleton of heart

Answer 155

- structural foundation for heart valves - attachment for myocardium - electrical insulation of atrial myocardium from ventricular (precise coordination of contraction)

Question 156

fibrous skeleton components

Answer 156

1) pulmonary fibrous ring (anterior): pulmonary semilunar valve 2) aortic fibrous ring (posterior): aortic semilunar valves 3) left atrioventricular fibrous ring 4) right atrioventricular fibrous ring

Question 157

coronary vessels (arteries)

Answer 157

two major branches: 1) left coronary artery bifurcates almost immediately into circumflex artery and anterior interventricular artery - circumflex: LA/LV - anterior interventricular: 2/3 IV septum of LV, anterior wall of LV/RV, connects with posterior interventricular artery at apex 2) right coronary artery gives rise to right marginal artery and posterior interventricular artery, supplies RA/RV - right marginal: RV - posterior interventricular artery: posterior 1/3 of IV septum, posterior RV/LV

Question 158

coronary vessels (veins)

Answer 158

1) great cardiac vein: drains areas supplied by anterior interventricular artery --> drain into coronary sinus 2) small and middle cardia veins: drains RCA area --> drain into coronary sinus 3) anterior cardiac vein: anterior RV --> drain directly into RA

Question 159

recognizing coronary vessels

Answer 159

- thick wall = aorta - thinner wall = pulmonary vein - big, dilated vessel near left side = coronary sinus

Question 160

conducting system of heart

Answer 160

1) sinoatrial node (pacemaker): automatically depolarize, impulses travel through internodal pathways to... 2) atriovenricular node: impulse slows, atria contract (superior to inferior), fibrous skeleton insulates ventricles from atrial depolarization 3) atrioventricular bundle branches into... 4) L/R bundle branches: conduct impulse through interventricular septum, right bundle transmits to septomarginal trabecula 5) subendocardial plexus: impulse goes upwards from apex, distributed to ventricular myocardium

Question 161

heart innervation

Answer 161

- autonomic nervous system innervates both SA/AV nodes and myocardium via cardiac plexus - SNS: increase HR through NE release - PNS: decrease HR through Ach release (vagus nerve) - cardiac centers in medulla control based on input from baroreceptors and chemoreceptors

Question 162

cardiac cycle

Answer 162

1) atrial systole: AV valves open, blood enters ventricles (relaxed) 2) atrial diastole: continues until start of next cycle 3) ventricular systole 1st phase: contraction closes AV valves ("lub") 4) ventricular systole 2nd phase: ventricular BP rises, SL valves open 5) early ventricular diastole: ventricular BP drops until reverse blood flow closes SL valve ("dub"), passive atrial filling 6) late ventricular diastole: passive ventricular filling, all chambers relaxed

Question 163

aortic valve regurgitation

Answer 163

- aortic valve that does not fully close - blood leaks back through during ventricular diastole - enlarged LV wall to cope with increased afterload

Question 164

pelvis structure

Answer 164

1) right and left hip bones (os coxae) joined anteriorly by pubic symphysis 2) sacrum (joins to hips by sacro-iliac joints) 3) coccyx

Question 165

pelvis function

Answer 165

1) support visceral organs 2) attachment point for muscles 3) transfer upper body weight to lower limb 4) attach lower limb to axial skeleton

Question 166

pelvic girdle

Answer 166

- consists of left and right hip bones

Question 167

hip bone structure

Answer 167

- three separate bones: 1) ilium (most superior) 2) ischium 3) pubis/pubic bone (anterior to ischium) - acetabulum: where bones fuse together around mid 20s, before separated by hyaline cartilage - obturator foramen: formed by 2/3, covered with fascia and muscle

Question 168

ilium features

Answer 168

lateral surface: 1) iliac crest 2) ala medial surface: 3) iliac fossa 4) arcuate line for muscle attachment: 5) anterior superior iliac spine 6) anterior inferior iliac spine 7) posterior superior iliac spine 8) posterior inferior iliac spine other: 9) greater sciatic notch: sciatic (largest nerve) passes through

Question 169

ischium features

Answer 169

1) ischial tuberosity: "big bump" that are "sit" bones, hamstrings attach here --> lateral view 2) ischial spine: muscle attachment 3) lesser sciatic notch 4) ischial ramus

Question 170

pubis features

Answer 170

1) pectineal line: medial view, continuous with arcuate line 2) superior pubic ramus 3) pubic tubercle: ligament attachment 4) body of pubis: between rami, forms pubic symphysis 5) inferior pubic ramus

Question 171

ischiopubic ramus

Answer 171

inferior pubic ramus + ischial ramus

Question 172

pelvic brim

Answer 172

- formed by: 1) sacral ala and promontory 2) arcuate line 3) pectineal line 4) superior pubic ramus 5) pubic symphysis - shaped differently in males and females (to accommodate childbirth

Question 173

pelvic inlet

Answer 173

space enclosed by pelvic brim

Question 174

pelvic outlet

Answer 174

space bordered by: 1) coccyx 2) ischial tuberosities 3) inferior border of pubic symphysis

Question 175

true vs false pelvis

Answer 175

- true = below pelvic brim, protects and contains pelvic viscera - false = above pelvic brim, encloses and protects lower abdominal viscera

Question 176

pelvic diaphragm

Answer 176

- aka pelvic floor - funnel-shaped sheet of muscle within pelvic outlet - formed by two major muscles and their fascia: 1) coccygeus 2) levator ani - muscles loop around urethra, vagina (if present) and anus --> controls urination and defecation - other functions: partitions true pelvis from perineum (contains external genitalia) and supports abdominopelvic viscera

Question 177

levator ani

Answer 177

- consists of three separate muscles 1) puborectalis: 'sling' around rectum 2) pubococcygeus: pubic bone to coccyx 3) iliococcygeus: ilium to coccyx - elevate anus - torn/stretched in childbirth

Question 178

coccygeus

Answer 178

- attaches to coccyx

Question 179

anterolateral abdominal wall

Answer 179

- no bony reinforcements - consist of fascia, muscles and their aponeuroses (thickening of CT) - muscle fibers run at right and oblique angles to one another + overlap = increase strength

Question 180

anterolateral abdominal wall muscles

Answer 180

(listed superficial to deep): 1) external oblique: fibers run inferomedially, same direction as external intercostals 2) rectus abdominis: vertical and enclosed by rectus sheath 3) internal oblique: fibers run superomedially 4) transversus abdominis: fibers run anteromedially 1-3 = flat, muscular laterally + aponeurotic medially

Question 181

linea alba

Answer 181

- collagen fibers of anterolateral abdominal wall muscle aponeuroses interlace here

Question 182

anterolateral abdominal wall muscles actions

Answer 182

1) stabilize vertebral column 2) compress abdominal contents 3) flexion of vertebral column (ex. sit-up motion) 4) rotation of vertebral column 5) lateral flexion of vertebral column

Question 183

inguinal ligament

Answer 183

- runs from anterior superior iliac spine to pubic tubercle - formed by lower border of external oblique - creates space where blood vessels and nerves pass through

Question 184

rectus abdominis structure

Answer 184

- extends from pubis to thoracic cage - segmented by three tendinous intersections: these sometimes don't line up because walls develop independently and later fuse together - enclosed by rectus sheath

Question 185

linea semilunaris

Answer 185

- where tendons of the lateral abdominal muscles meet the sheath surrounding the rectus abdominis muscle

Question 186

rectus abdominis action

Answer 186

1) flexion of vertebral column 2) compress abdominal viscera

Question 187

rectus sheath

Answer 187

- surrounds rectus abdominis - anterior layer formed by external oblique and some internal oblique aponeuroses - posterior layer formed by transversus abdominis and some internal oblique aponeuroses

Question 188

arcuate line in anterolateral abdominal wall

Answer 188

- posterior to rectus abdominis - marks transition on rectus sheath where all aponeurotic layers pass anteriorly - below line: fascia is thinner

Question 189

posterior abdominal wall structures

Answer 189

1) some bones: lumbar vertebrae, sacrum, ilia, ribs 11/12 2) posterior abdominal wall muscles: attach to vertebrae 3) portion of diaphragm 4) kidneys, suprarenal glands and fascia: lie on top of the wall 5) fat, nerves, blood vessels

Question 190

posterior abdominal wall muscles

Answer 190

1) diaphragm 2) transversus abdominis: forms belt around abdomen 3) quadratus lumborum: 4 sided, attached to lumbar vertebrae and 12th rib 4) iliacus: fills iliac fossa, continues to lower limbs 5) psoas major: attaches to lumbar vertebrae, continues to lower limbs (in front of 3)) *4/5 pass under the inguinal ligament

Question 191

abdominal wall layers

Answer 191

1) skin 2) superficial fascia 3) muscles/vertebra 4) transversalis fascia: lines inside of abdominal wall, called renal fascia around kidneys 5) extraperitoneal (visceral) fat 6) peritoneum 7) peritoneal cavity

Question 192

peritoneum

Answer 192

- continuous serous membrane in peritoneal cavity that invests some viscera - two layers of mesothelium that secrete fluid: 1) visceral 2) peritoneal cavity: doesn't actually contain organs! 3) parietal

Question 193

intraperitoneal organs

Answer 193

- surrounded by visceral peritoneum - suspended by mesenteries to posterior abdominal wall - ex. stomach, spleen

Question 194

retroperitoneal organs

Answer 194

- develop posterior to peritoneal cavity - only partially covered by peritoneum - ex. kidneys, aorta, IVC, pancreas

Question 195

arteries of posterior abdominal wall

Answer 195

- branch from aorta - unpaired visceral branches: 1) celiac trunk 2) superior mesenteric artery 3) inferior mesenteric artery - paired: 4) suprarenal arteries 5) renal arteries 6) gonadal arteries 7) lumbar arteries

Question 196

veins of posterior abdominal wall

Answer 196

- drain into inferior vena cava - unpaired: 1) hepatic veins: drain liver (all digestive system blood goes to liver) - paired: 2) suprarenal veins 3) renal veins 4) gonadal veins: left drains into left renal vein, right drains directly into IVC 5) lumbar veins

Question 197

digestive system function

Answer 197

- mechanically and chemically break down food for absorption

Question 198

digestive system organ groups

Answer 198

1) gastrointestinal tract: form continuous tube = mouth, pharynx, esophagus, stomach, small intestine, large intestine 2) accessory digestive organs: connected to GI tract = teeth, tongue, salivary glands, liver, gallbladder, pancreas

Question 199

secondarily retroperitoneal organs

Answer 199

- initially intraperitoneal - become attached to posterior body wall through development (part of peritoneum disintegrates) - ex. ascending and descending colon

Question 200

mesenteries

Answer 200

- double layer of peritoneum with intervening areolar CT - blood, lymph vessels, nerves sandwiched between - several types/names - function: support and stabilize intraperitoneal organs

Question 201

mesentery examples

Answer 201

1) transverse mesocolon 2) mesentery proper: largest 3) sigmoid mesocolon: helps suspend part of colon

Question 202

GI tract general layers

Answer 202

1) mucosa: protection, absorption, secretion 2) submucosa 3) muscularis externa 4) serosa or adventitia

Question 203

GI mucosa

Answer 203

1) epithelium: varies based on tube function 2) lamina propria: areolar CT with mucosal glands, blood vessels, nerves, lymphatics 3) muscularis mucosae: smooth muscle, alters shape of lumen

Question 204

GI submucosa

Answer 204

- dense irregular or areolar CT - blood, lymphatics, submucosal plexus - some regions: lymphatic tissue and submucosal glands

Question 205

GI muscularis externa

Answer 205

- two layers of smooth muscle (except in esophagus and stomach): inner circular and external longitudinal - myenteric plexus located between layers - contraction of layers = segmentation and peristalsis - circular = compression, mixing, constricting diameter - longitudinal = shortens length of tube

Question 206

GI adventitia/serosa

Answer 206

- areolar CT - intraperitoneal organs = serosa - others = adventitia

Question 207

peristalsis

Answer 207

1) contraction of circular muscles behind bolus 2) contraction of longitudinal muscles ahead of bolus 3) wave of contraction in circular muscle layer forces bolus forward

Question 208

segmentation

Answer 208

- primarily circular muscle layers - churn and mix contents in digestive tract - no net movement in particular direction

Question 209

esophagus

Answer 209

- muscular tube running through neck and posterior mediastinum - passes through muscular part of diaphragm via esophageal hiatus - 25cm x 2cm - secretes mucus (lubrication - transports swallowed materials from pharynx to stomach

Question 210

esophagus layers

Answer 210

1) mucosa: - stratified squamous nonkeratinized epithelium - lamina propria: lymphatic nodules and esophageal cardiac glands - thick muscularis mucosae 2) submucosa: - dense irregular CT - blood and lymphatics - lots of elastic fibers (collapsed lumen), assist in closing tube - submucosal glands 3) muscular layer: - circular and longitudinal - proximal to distal: 1/3 skeletal muscle, 1/3 both, 1/3 smooth 4) adventitia: adheres to posterior body wall

Question 211

esophagus bolus path

Answer 211

- passes through esophageal hiatus to portion located in peritoneal cavity - pass through lower esophageal sphincter (cardiac sphincter): thickening of circular layer - goes to stomach

Question 212

gastroesophageal reflux disease (GERD)

Answer 212

- lower esophageal sphincter fails to close adequately - HCl from stomach irritates esophageal wall - long-term: epithelium changes to simple columnar and scar tissues build up, changing function and narrowing lumen

Question 213

stomach regions

Answer 213

1) fundus: dome shaped 2) cardia: transition zone between esophagus and stomach 3) body: majority 4) pyloric antrum: funnel-shaped

Question 214

stomach structure

Answer 214

- J-shaped, with four regions - lesser curvature: lesser omentum (mesentery) attachment - greater curvature: greater omentum - rugae (semipermanent folds) formed by mucosa and submucosa, accommodate expansion and filling of stomach

Question 215

stomach muscularis externa

Answer 215

- three layers: 1) longitudinal 2) circular 3) oblique: additional layer to allow more effective mixing

Question 216

stomach function

Answer 216

- food (chyme) storage - mechanical/chemical digestion - hormone secretion - little absorption

Question 217

pyloric sphincter

Answer 217

- thickening of circular layer - regulates chyme movement from stomach to duodenum

Question 218

stomach layers

Answer 218

1) mucosa: - simple columnar epithelium - mucous cells invaginate into lamina propria = gastric pits - muscularis mucosae 2) submucosa: - loose areolar CT with BVs, lymphatics - no glands! 3) muscularis externa: 3 layers 4) serosa: loose areolar CT

Question 219

gastric secretions

Answer 219

1) surface mucous and mucous neck cells: mucins, protects mucosa from acid and maintains acidic conditions 2) parietal cells: intrinsic factor (B12 absorption), HCl (denatures proteins, antibacterial, breaks down cell walls) 3) chief cells: pepsinogen (proenzyme --> pepsin with HCl), gastric lipase 4) G cells (enteroendocrine): gastrin into blood stream, stimulates parietal/chief cells and contractions

Question 220

stomach secretory cell distribution

Answer 220

- gastric pit: mucous cells - gastric gland: parietal, G, chief - chief cells more predominant at bottom of gland - G cells at bottom, not seen on H&E

Question 221

parietal vs chief cells histology

Answer 221

- parietal = large, central nucleus, eosinophilic - chief = small, basophilic (proteins)

Question 222

small intestine function

Answer 222

most digestion and absorption

Question 223

small intestine regions

Answer 223

1) duodenum (~25cm, shortest): mix chyme with exocrine secretions, proximally intraperitoneal (mobile) and rest secondarily retroperitoneal (anchored) 2) jejunum (2.5m): chemical digestion, nutrient absorption, intraperitoneal 3) ileum (3.6m): controls movement of intestinal contents into cecum, intraperitoneal

Question 224

mesenteries of small intestine

Answer 224

- duodenum: no mesentery - jejunum and ileum: fan-shaped mesentery proper (anchor to posterior wall)

Question 225

small intestine structures

Answer 225

1) circular folds (plicae circulares): permanent, transverse folds of mucosa and submucosa = increase SA and slow chyme 2) intestinal villi: finger-like extensions of mucosa, covered by simple columnar cells, also increase SA 3) microvilli: projections from intestinal villi (brush border), increase SA

Question 226

small intestine layers

Answer 226

1) mucosa: - villi, intestinal glands, lymphoid nodules - muscularis mucosae - simple columnar with goblet cells - lamina propria: capillary networks (nutrient-rich blood to liver), lacteals (lipid-protein complexes to venous system), nerves and smooth muscle 2) submucosa: lymphatics, vessels, submucosal neural plexus 3) muscular layer: - circular and longitudinal - myenteric neural plexus 4) serosa

Question 227

small intestine plexuses

Answer 227

- control movement of chyme and secretions

Question 228

intestinal glands (crypts)

Answer 228

- extend into lamina propria - enteroendocrine cells: hormone production, ex. CCK - paneth cells: innate immunity - stem cells: replenish epithelial cells lost in lumen and MALT

Question 229

small intestine regional specializations

Answer 229

1) duodenum: mucous secretion and goblet cells, with submucosal (Brunner's) glands 2) jejunum: nutrient absorption, well developed circular folds 3) ileum: lymphoid nodules (Peyer's patches, target bacteria from large intestine), goblet cells (lubrication after lots of absorption)

Question 230

large intestine structure

Answer 230

- from ileocecal valve to anus (1.5m long, 6.5cm wide) - large = wider (shorter than small) - three regions 1) cecum: blind ended sac (contents can only go up) 2) colon: ascending, transverse, descending, sigmoid 3) rectum

Question 231

large intestine function

Answer 231

- reabsorption of water and salts - absorption of vitamins - storage of feces

Question 232

large intestine feactures

Answer 232

1) right colic (hepatic) flexure 2) left colic (splenic) flexure 3) haustra: permit expansion, created by... 4) teniae coli (3 strips): reorganization of external longitudinal layer 5) epiploic (omental) appendages: fatty appendages along teniae coli, function unknown

Question 233

appendix

Answer 233

- filled with lymphoid nodules and involved in immune function - attached to cecum

Question 234

retroperitoneal and intraperitoneal parts of large intestine

Answer 234

1) ascending colon = secondarily retroperitoneal 2) transverse colon = intra 3) descending colon = secondarily retro 4) sigmoid colon = intra 5) rectum = retro

Question 235

greater omentum connections

Answer 235

- connects stomach to transverse colon

Question 236

rectum characteristics

Answer 236

- expandable, filling = urge to defecate - ends as anal canal, opens to outside at the anus - epithelium changes: 1) simple columnar 2) stratified squamous nonkeratinized 3) keratinized

Question 237

rectum features

Answer 237

1) anal canal: circular folds hold feces 2) internal anal sphincter: smooth muscle, thickening of inner circular muscular layer = reflex control 3) external anal sphincter: skeletal muscle = voluntary control

Question 238

large intestine layers

Answer 238

1) mucosa: - changing epithelium - no villi or circular folds - goblet cells, deep intestinal glands - muscularis mucosae 2) submucosa 3) muscular layer: - circular layer - longitudinal layer = teniae coli 4) serosa

Question 239

large intestine control

Answer 239

- regulated by local reflexes in ANS - proximally: fecal material moves slowly by peristalsis, segmentation by haustral churning - mass movements: powerful, peristaltic-like contraction involving teniae coli (infrequently, ~2-3x/day) - rectal distension consciously sensed = sphincter relaxation

Question 240

arterial supply of digestive system

Answer 240

1) celiac trunk = foregut: - left gastric artery: lesser omentum - splenic artery: greater omentum, spleen, pancreas - common hepatic artery: liver, gall bladder, proximal duodenum, connects to left gastric artery 2) superior mesenteric artery = midgut: distal duodenum to left colic flexure 3) inferior mesenteric artery = hindgut: descending colon to upper rectum (also, esophageal arteries, visceral branches of thoracic aorta)

Question 241

hepatic portal system

Answer 241

1) hepatic portal vein: carries nutrient rich and O2 poor blood from digestive system (all other veins) to liver 2) left gastric vein 3) splenic vein 4) inferior mesenteric vein 5) superior mesenteric vein 6) hepatic veins: drain blood from liver to IVC *no common hepatic or celiac vein!

Question 242

portal vein definition

Answer 242

- connects two capillary beds

Question 243

liver capsule

Answer 243

- covered by fibrous CT capsule and visceral peritoneum, except at bare area - peritoneum reflects to make ligaments

Question 244

liver lobes

Answer 244

two major: 1) right 2) left two smaller (only visible posteriorly) 3) caudate: next to IVC 4) quadrate: next to gall bladder

Question 245

liver ligaments

Answer 245

1) coronary ligament: attaches to diaphragm 2) falciform ligament: attachment to anterior body wall 3) round ligament: free edge of falciform, remnant of fetal umbilical vein

Question 246

liver bare area

Answer 246

- close proximity to diaphragm - coronary ligament around attaches to diaphragm

Question 247

porta hepatis

Answer 247

- structure in liver containing: BVs, lymph, bile ducts and nerves - lateral to medial: common hepatic duct, hepatic artery proper, hepatic portal vein (more posterior) - housed under lesser omentum

Question 248

liver functions

Answer 248

1) digestive: produce and secrete bile, facilitate fat digestion, buffer acidity in chyme 2) metabolic: regulate circulating levels of nutrients, store fat-soluble vitamins, remove metabolic wastes and toxins 3) hematological: synthesize plasma proteins, phagocytize debris in blood, blood reservoir

Question 249

lesser omentum attachments

Answer 249

- attaches stomach to liver

Question 250

liver functional units

Answer 250

- divided by CT (interlobular septum, containing interlobular veins and arteries) into lobules - commonly hexagonal shaped - portal triads at periphery: include branches of hepatic portal vein, hepatic artery proper and bile duct - central vein in the middle

Question 251

blood flow through liver

Answer 251

1) blood from hepatic portal vein and hepatic artery proper drain into hepatic sinusoids (sinusoidal vessel) 2) drain into central vein 3) central veins merge to form hepatic veins 4) empty into IVC

Question 252

blood processing in liver

Answer 252

- as blood passes through, it is processed by: 1) hepatocytes: nutrient packaging, metabolism, bile production, blood processing 2) stellate macrophages: vit A and fat storage

Question 253

liver perisinusoidal space

Answer 253

- separates hepatocytes from endothelial cells - where functions of the liver take place

Question 254

bile flow in liver

Answer 254

1) produced by hepatocytes 2) secreted into bile canaliculi 3) bile ductules 4) bile ducts 5) hepatic ducts: one for each lobe, collects all bile ducts 6) common hepatic duct 7) cystic duct to store in gall bladder 8) OR common bile duct: common hepatic + cystic duct --> major duodenal papilla

Question 255

bile function

Answer 255

- digestion of lipids in duodenum

Question 256

hepatopancreatic ampulla

Answer 256

- collects from common bile duct and pancreatic duct - flow controlled by hepatopancreatic sphincter: formed by part of duodenum wall - lipid/protein-containing chyme stimulates enteroendocrine cell release of CCK - CCK stimulates gallbladder contraction and hepatopancreatic sphincter relaxation

Question 257

pancreas characteristics

Answer 257

- posterior to stomach, incurve of duodenum - secondarily retroperitoneal - ~15cm long - head, body and tail (tail near spleen) - surrounded by thin fibrous CT capsule - divided into lobules by CT septa - endocrine and exocrine functions

Question 258

pancreatic blood supply

Answer 258

1) celiac trunk 2) superior mesenteric artery

Question 259

pancreas histology

Answer 259

1) pancreatic islets: endocrine = lighter staining 2) acinar cells: make up acini, exocrine = darker staining, eosinophilic lumen

Question 260

pancreatic cell types and functions

Answer 260

1) pancreatic islets (contain many diff cells): endocrine products, ex. insulin/glucagon --> BVs 2) acinar cells: mucin, digestive enzymes 3) intercalated duct cells: bicarbonate ions, mix with digestive enzymes to go towards small intestine via pancreatic duct

Question 261

urinary system component

Answer 261

kidneys, ureters, bladder, urethra

Question 262

urinary tract components and function

Answer 262

- ureters, bladder, urethra - store and eliminate urine

Question 263

kidney function

Answer 263

- maintenance of water and electrolyte homeostasis - elimination of by-products of metabolism: urine production

Question 264

filtration/reabsorption in kidney

Answer 264

- blood filtered, most reabsorbed - rest is filtrate converted to urine

Question 265

urinary system function

Answer 265

- elimination of organic wastes, toxins and some drugs - conservation of nutrients - storage/excretion of urine - regulation of blood volume and pressure - regulation of erythrocyte production - regulation of blood electrolyte concentration and pH

Question 266

kidney location

Answer 266

- either side of VC between T12-L3 - right: posterior to liver, right colic flexure, duodenum - left: medial to spleen, posterior to stomach, pancreas, left colic flexure, small intestine

Question 267

kidney structure

Answer 267

1) superior pole: adrenal glands 2) hilium: renal BVs (vein anterior to artery), lymphatics, nerves, renal pelvis 3) ureter 4) inferior pole

Question 268

renal pelvis

Answer 268

- connection to ureter in kidney

Question 269

kidney coverings

Answer 269

deep to superficial: 1) fibrous capsule: thin dense irregular CT, maintains shape and protects 2) perinephric fat: cushioning and support 3) renal fascia: dense irregular CT, anchors kidney to surrounding structures and posterior abdominal wall 4) paranephric fat

Question 270

L/R renal vein and artery differences

Answer 270

- L vein longer bc IVC closer to L - L artery shorter bc aorta closer to R

Question 271

internal features of kidneys

Answer 271

1) renal pyramid: renal medulla, has apex and base (abuts renal cortex) 2) renal papilla: formed by apex of renal pyramid, extends into minor calyx 3) renal columns: cortical tissue between pyramids 4) renal lobe: location of renal functional units, includes pyramid and adjacent cortex/columns 5) minor calyx: drains medulla into... 6) major calyx: formed by merging minor 7) renal pelvis: drains major calyxes 8) renal sinus: contains fat

Question 272

blood supply to kidney

Answer 272

1) R/L renal arteries 2a) accessory artery 2b) segmental artery, divides further 3) interlobar arteries 4) arcuate arteries 5) cortical radiate arteries: branch into afferent arterioles and supply nephrons *all are end arteries: do not anastamose with others

Question 273

blood drainage from kidney

Answer 273

- all arteries typically associated with veins - efferent arterioles drain nephrons (functional unit of kidney)

Question 274

nephron components

Answer 274

1) renal corpuscle: spherical, contains glomerulus (bundle of BVs) and glomerular capsule 2) renal tubule: PCT, nephron loop, DCT

Question 275

renal corpuscle function

Answer 275

- filter blood - produce glomerular filtrate (enters capsular space)

Question 276

renal tubule function

Answer 276

- modifies glomerular filtrate through reabsorption/secretion

Question 277

types of nephrons

Answer 277

1) cortical (85%): primarily in cortex, produce glomerular filtrate 2) juxtamedullary nephrons (15%): close to junction between cortex and medulla, extend into medulla, produce filtrate and ALSO create/maintain osmotic gradient in renal interstitium

Question 278

importance of renal interstitium osmotic gradient

Answer 278

- concentration of urine - modification of filtrate as it passes through

Question 279

nephron blood supply

Answer 279

1) renal artery 2) segmental 3) interlobar 4) arcuate 5) cortical radiate 6) afferent arterioles in nephron: 7) glomerulus 8) efferent arteriole 9) peritubular capillaries or vasa recta 10) venules 11) same veins, except no segmental veins

Question 280

peritubular capillaries

Answer 280

- around PCT/DCT - gas, nutrient, waste exchange

Question 281

vasa recta

Answer 281

- around nephron loop - gas, nutrient, waste, exchange

Question 282

afferent vs efferent arteriole

Answer 282

- afferent wider - creates increased hydrostatic pressure that drives H2O and low MW molecules through filter to form filtrate

Question 283

urine formation

Answer 283

renal corpuscle: 1) glomerular filtration: movement of substances from blood within glomerulus to capsular space renal tubule and collecting duct: 2) tubular reabsorption: movement of substances back to blood from tubular fluid (most) 3) tubular secretion: movement of substances from blood to tubular fluid

Question 284

glomerular capsule layers

Answer 284

1) parietal layer: simple squamous cells 2) capsular space: contains glomerular filtrate 3) visceral layer: specialized cells (podocytes) with bulging nuclei and interlaced digits

Question 285

glomerulus structure

Answer 285

1) vascular pole: where afferent arteriole and efferent arteriole enter 2) tubular pole: PCT 3) DCT closely associated with arterioles

Question 286

filtration membrane in kidney

Answer 286

- negatively charged - three layers: 1) fenestration of glomerular endothelial cells: prevents blood cells, but all other plasma components can flow through 2) basal lamina of glomerulus: blocks larger proteins 3) slit membrane between podocytes (pedicels): blocks medium-sized proteins

Question 287

PCT characteristics

Answer 287

- located in cortex - simple cuboidal with very dense microvilli: most absorption in PCT

Question 288

PCT functions

Answer 288

- active reabsorption of ions, nutrients, vitamins, plasma proteins from filtrate to peritubular fluid (H2O follows passively), peritubular capillaries return these to general circulation - active secretion of organic acids/bases, metabolites, drugs into PCT lumen

Question 289

nephron loop characteristics

Answer 289

- descending limb - ascending limb: impermeable to water, actively pumps Na/Cl out of tubular fluid to concentrate interstitial fluid, drawing water with it (reabsorption), vasa recta returns to circulation - each has thick (simple cuboidal) and thin (simple squamous) segment - most water and NaCl reclaimed at this point

Question 290

DCT characteristics

Answer 290

- in cortex, passes vascular pole in renal corpuscle between afferent/efferent arterioles - simple cuboidal with FEW, BLUNT microvilli - smaller diameter than PCT - shorter than PCT

Question 291

DCT function

Answer 291

- active secretion of K/H into tubular fluid - reabsorption of NaCl, H2O when aldosterone and ADH present

Question 292

PCT vs DCT on H&E stain

Answer 292

- PCT: bigger cells, not every cell has nucleus, fuzzy lumen - DCT: smaller cells all with nuclei, empty lumen

Question 293

juxtaglomerular complex function

Answer 293

- regulate glomerular filtration rate (GFR) and blood pressure - ex. BP drop = lower Na in filtrate = SyNS input and release of renin

Question 294

juxtaglomerular complex components

Answer 294

1) macula densa: modified epithelial cells in DCT, monitor [Na] in fluid 2) juxtaglomerular cells: modified (contractile to secretory) smooth muscle cells of afferent arteriole, monitor BP and innervated by SyNS for renin secretion (increases BP) 3) extraglomerular mesangial cells: surround and support vascular pole, FN not well understood

Question 295

juxtaglomerular complex histology

Answer 295

1) macula densa: cells more columnar, contact afferent arteriole 2) juxtaglomerular cells: hard to see, but near afferent arteriole 3) extraglomerular mesangial cells: in space between afferent and efferent arterioles

Question 296

collecting system function

Answer 296

- transport fluid from DCT to minor calyx - make final adjustments to osmotic concentrations and volume - ADH controls permeability ex. dehydration = more ADH = more H2O reabsorption = more concentrated urine

Question 297

collecting system comonents

Answer 297

1) collecting tubules 2) collecting ducts 3) papillary ducts

Question 298

collecting system histology

Answer 298

- tubules = simple cuboidal - ducts = simple columnar - collecting ducts have pale staining principal cells with few organelles and DISTINCT cell borders

Question 299

ureter location

Answer 299

- retroperitoneal - extend from renal pelvis to posterolateral wall of bladder (oblique angle)

Question 300

ureter layers

Answer 300

1) mucosa: transitional epithelium and lamina propria 2) smooth muscular layer: longitudinal inner, circular outer 3) adventitia (CT)

Question 301

bladder location

Answer 301

- posterior to pubic symphysis - retroperitoneal (superior surface covered with peritoneum) - shape and location differ in M/F

Question 302

urethra location

Answer 302

- from urinary bladder to exterior - longer in males - shorter in females, UTIs more common

Question 303

bladder features

Answer 303

1) rugae: formed by mucosal folds, allow for greater distension 2) trigone region: smooth, funnels urine from ureters to urethra 3) internal urethral sphincter: only in males, organized smooth muscle 4) detrusor muscle: 3 layers, contract to expel urine

Question 304

urethra structure in males

Answer 304

1) prostatic urethra: goes through prostate 2) membranous urethra: passes through external urethral sphincter 3) spongy: penis

Question 305

bladder layers

Answer 305

1) mucosa: transitional epithelium and lamina propria 2) submucosa 3) thick detrusor muscle 4) adventitia

Question 306

urethra histology

Answer 306

- large longitudinal folds around lumen - surrounded by bundles of smooth muscle - females: stratified squamous - males: changes from transitional --> stratified columnar/pseudostratified columnar --> stratified squamous

Question 307

micturation control

Answer 307

1) bladder not full: SyNS (T11-L2) inhibit detrusor contraction, stimulate internal urethral sphincter 2) bladder full: baroreceptors and sensory axons (T11-L2) relay info to brain, PSyNS stimulate detrusor contraction and relax internal sphincter, somatic motor (S2-S4) relax external urethral sphincter

Question 308

exocrine gland

Answer 308

- duct connects gland to external environment - secretory cells release chemical products onto epithelial surface via duct - ex. eccrine sweat glands

Question 309

endocrine glands

Answer 309

- no connection to epithelial layer = ductless - secrete chemical products (hormones) into surrounding tissue --> blood stream - ex. endocrine pancreas

Question 310

endocrine organs

Answer 310

1) CNS: hypothalamus, pituitary gland 2) thoracic cavity: thyroid, parathyroid 3) abdominal cavity: adrenal/suprarenal, pancreas

Question 311

endocrine system functions

Answer 311

- secrete hormones that act on receptors that modulate the biochemistry of target cells - maintain homeostasis through endocrine reflexes and feedback loops

Question 312

characteristics of endocrine organs

Answer 312

- clusters or cords of secretory cells - surrounded by supportive dense irregular CT - highly vascularized with fenestrated (most) or sinusoidal capillaries

Question 313

neural vs endocrine signaling

Answer 313

1) same function = regulate body functions to maintain homeostasis 2) mechanism: electrical signaling and chemical neurotransmitters through nervous system ("wired") vs chemical hormones distributed through CV system ("wireless"), BOTH act on specific receptors 3) speed: relatively fast vs slow 4) effect duration: short vs long-term 5) recovery: fast vs slow, BOTH regulated by feedback loops 6) location: localized/specific vs widespread/diffuse

Question 314

types of hormones

Answer 314

1) amino acid derivatives 2) peptide hormones: largest class 3) steroid hormones

Question 315

endocrine reflex

Answer 315

1) stimulus 2) integrating center 3) hormone 1 4) integrating center 5) hormone 2 6) target tissue 7) response *feedback can be negative or positive

Question 316

types of endocrine stimuli

Answer 316

1) humoral: changes in extracellular fluid composition 2) hormonal: changes in hormonal levels 3) neural: presence of neurotransmitter at neuroglandular junction

Question 317

hypothalamus mechanisms

Answer 317

- coordination center, regulates nervous and endocrine system by: 1) secreting regulatory hormones 2) functioning as an endocrine organ 3) direct neural control (endocrine cells of adrenal gland)

Question 318

hypothalamus regulatory hormones

Answer 318

- control endocrine cells in anterior pituitary gland - two classes: 1) releasing: stimulate synthesis and secretion of hormones 2) inhibiting: prevent

Question 319

hypothalamus endocrine organ function

Answer 319

- neurons directly synthesizing hormones, transport to posterior pituitary - released at posterior pituitary - ex. ADH, oxytocin

Question 320

hypothalamus direct neural control

Answer 320

- ANS centers control autonomic output - SyNS activation = suprarenal medulla release of hormones into circulation

Question 321

pituitary gland functions

Answer 321

1) tropic functions: modulate other endocrine glands 2) non-tropic functions: act directly on non-endocrine systems

Question 322

pituitary structure

Answer 322

1) infundibulum: stalk portion connecting hypothalamus and pituitary glands 2) anterior pituitary (adenohypophysis) 3) posterior pituitary (neurohypophysis, pars nervosa) 4) sella turcica: hypophyseal fossa of spehnoid, houses glands

Question 323

anterior pituitary divisions

Answer 323

1) pars distalis: most distal 2) pars intermedia: separates anterior/posterior 3) pars tuberalis: forms part of infundibulum

Question 324

anterior pituitary control

Answer 324

- regulatory hormones from hypothalamus via hypophyseal portal system

Question 325

hypophyseal portal system

Answer 325

1) superior hypophyseal artery: branch from internal carotid 2) primary capillary plexus: hypothalamic neurons release hormones here 3) hypothalamic portal veins: carry hormones to AP 4) secondary capillary plexus: regulatory hormones modulate AP activity, AP release hormones here 5) hypophyseal veins: drain blood into general circulation via cavernous sinus

Question 326

anterior pituitary cell types

Answer 326

1) chromophils i) acidophils: prolactin, growth hormones ii) basophils: FSH, LH, ACTH, TSH (FLAT) 2) chromophobes: don't stain well

Question 327

anterior pituitary histology

Answer 327

- acidophils = eosinophilic - basophils = basophilic - chromophobes = don't stain - more basophilic (darker) than posterior pituitary

Question 328

posterior pituitary control

Answer 328

- axons from paraventricular and supraoptic nuclei of hypothalamus travel through infundibulum to PP - hormones produced by PVN/SON travel along axon to synaptic terminals of PP --> released into interstitium, taken up by capillaries - SON = ADH - PVN = oxytocin

Question 329

posterior pituitary blood supply

Answer 329

1) inferior hypophyseal artery: branch from meningohypophyseal trunk of internal carotid 2) hypohpyseal veins: drain released ADH and oxytocin to general circulation

Question 330

posterior pituitary histology

Answer 330

1) herring bodies: intense staining clusters = terminal end of axons where hormones are stored 2) blood vessels 3) pituicytes: glial cells *very eosinophilic

Question 331

ADH function

Answer 331

- act on kidneys and circulatory system for water reabsorption and increasing BV/BP

Question 332

oxytocin function

Answer 332

- female reproductive system - uterine contractions (positive feedback loop)

Question 333

FSH/LH function

Answer 333

- hypothalamic hormone = GnRH - follicular cells in ovary, nurse/interstitial cells of testes - FSH = estrogen secretion, sperm maturation - LH = testosterone secretion, ovulation

Question 334

TSH function

Answer 334

- hypothalamic hormone = TRH - thyroid gland hormone production

Question 335

prolactin function

Answer 335

- hypothalamic hormone = PRH - mammary gland milk production

Question 336

growth hormone function

Answer 336

- hypothalamic hormone = GHRH - liver, bone, muscle - growth, protein synthesis, lipid metabolism

Question 337

ACTH function

Answer 337

- hypothalamic hormone = CRH - adrenal gland glucocorticoid production

Question 338

thyroid gland characteristics

Answer 338

- two lobes connected by isthmus, created by surrounding DICT capsule - butterfly-shaped - anterior surface of trachea: cartilage ring 2-3 - easily palpable with fingers, especially when enlarged (goiter) - highly vascularized

Question 339

thyroid arterial supply

Answer 339

1) external carotid artery --> superior thyroid artery 2) subclavian artery --> thyrocervical trunk, inferior thyroid artery

Question 340

thyroid venous drainage

Answer 340

1) internal jugular veins --> superior thyroid and middle thyroid veins 2) brachiocephalic vein --> inferior thyroid vein

Question 341

thyroid gland structure

Answer 341

- enclosed in fibrous capsule that sends trabeculae deep into the gland = irregular lobules - functional unit = thyroid follicle (spherical) - follicular cells = thyrocytes - parafollicular (C) cells between thyroid follicles

Question 342

thyroid follicle

Answer 342

- simple cuboidal epithelium (can change to columnar if more active) - cavity filled with colloid (viscous fluid)

Question 343

thyrocyte functions

Answer 343

1) synthesize thyroglobulin (prohormone) 2) secrete colloid --> become iodinated 3) breakdown to form thyroid hormones: thyroxine (T4, storage) and triiodothyronine (T3, active form)

Question 344

parafollicular (C) cell function

Answer 344

- secrete calcitonin, which decreases [Ca]: 1) inhibits osteoclast activity 2) stimulates Ca excretion at kidneys

Question 345

hypothalamus-pituitary-thyroid (HPT) axis

Answer 345

1) low body temperature 2) hypothalamus: releases TRH 3) anterior pituitary: releases TSH 4) thyroid: produces thyroid hormones 5) increase metabolic rate, increase body temperature 6) negative feedback to hypothalamus and anterior pituitary through homeostasis restoration

Question 346

parathyroid glands location

Answer 346

- 4 pea-sized, located on posterior aspect of thyroid gland - two superior, two inferior

Question 347

parathyroid blood supply

Answer 347

- superior = superior thyroid arteries - inferior = inferior thyroid arteries - venous drainage same as thyroid gland

Question 348

parathyroid characteristics

Answer 348

- surrounded by CT capsule that forms irregular lobules - two specialized cell types: 1) parathyroid cells (chief/principal): produce parathyroid hormone 2) oxyphil cells: immature/inactive parathyroid cells

Question 349

parathyroid gland control

Answer 349

- humoral stimulus = [Ca] in circulation - decrease in Ca stimulates PTH secretion

Question 350

PTH function

Answer 350

1) stimulate osteoclasts and osteoblasts (needed to activate osteoclasts) 2) reduce urinary Ca excretion 3) stimulate calcitriol production (kidney, increases intestinal absorption of Ca)

Question 351

parathyroid gland histology

Answer 351

- very cellular - oxyphil cells: more cytoplasm

Question 352

adrenal (suprarenal) gland characteristics

Answer 352

- pyramid-shaped - one on each superior pole of kidney (retroperitoneal) - CT capsule - highly vascularized - two regions: cortex (superficial) and medulla (deep)

Question 353

adrenal arterial supply

Answer 353

1) abdominal aorta --> superior and middle adrenal arteries 2) renal artery --> inferior adrenal arteries

Question 354

adrenal cortex characteristics

Answer 354

- cells with high lipid content that secrete 24 types of steroid hormones (adrenocortical steroids) - three layers (superficial to deep): 1) zona glomerulosa: cells in densely packed clusters ("glomeruli), produce mineralocorticoids ex. aldosterone 2) zona fasciculata: cells in radiating cords, separated by fenestrated capillaries, produce glucocorticoids ex. cortisol 3) zona reticularis: reticular network of small cells, produce androgens

Question 355

adrenal medulla characteristics

Answer 355

- primarily chromaffin cells: large, rounded, resemble sympathetic ganglia neuron (modified postganglionic sympathetic neuron) - two types of endocrine cells that secrete catecholamines: 80% epinephrine, 20% NE

Question 356

adrenal medulla innervation

Answer 356

- by sympathetic preganglionic neurons --> splenic nerve --> target cells

Question 357

adrenal medulla function

Answer 357

- trigger utilization of cellular energy to increase muscle strength and endurance

Question 358

hypothalamus-pituitary-adrenal (HPA) axis

Answer 358

1) stress 2) hypothalamus releases corticotropin releasing hormone 3) anterior pituitary releases ACTH 4) adrenal cortex releases cortisol 5) stress response *4/5 act as negative feedback on hypothalamus and anterior pituitary

Question 359

pancreas characteristics

Answer 359

- retroperitoneal - head, body, tail - mixed gland: acini/ducts are exocrine (99%), pancreatic islets are endocrine

Question 360

pancreas blood supply

Answer 360

- pancreatic branches of: 1) splenic artery 2) pancreaticoduodenal arteries

Question 361

pancreatic islets characteristics

Answer 361

- aka islet of langerhans - surrounded by CT - fenestrated capillaries - ANS input through celiac plexus

Question 362

pancreatic islet cell types

Answer 362

1) alpha cells: glucagon 2) beta cells: insulin 3) delta cells: somatostatin, inhibits alpha/beta cell production 4) F cells (least common): pancreatic polypeptide, inhibits gallbladder contraction, regulates enzyme production (overall slows digestion) *cannot be distinguished on H&E stain

Question 363

low blood glucose reflex

Answer 363

1) alpha cells release glucagon 2) increased glycogen breakdown in liver 3) increase blood glucose

Question 364

high blood glucose reflex

Answer 364

1) beta cells release insulin 2) stimulates glucose uptake 3) more glycogen formation in liver 4) decrease blood glucose

Question 365

reproductive system components

Answer 365

1) primary sex organs = gonads = testes and ovaries 2) accessory organs

Question 366

gonads function

Answer 366

- produce haploid gametes and sex hormones - ovary = oocytes, estrogen, progesterone - testes = sperm, androgens - gametes fuse to form diploid zygote

Question 367

activation of reproductive systems

Answer 367

- primarily non-functional until puberty, when hypothalamus releases GnRH - acts on ant. pituitary = FSH/LH release - at puberty: external sex characteristics develop, gametes mature and gonads start to secrete sex hormones

Question 368

components of male reproductive system

Answer 368

1) genital ducts: ductus (vas) deferens, ejaculatory duct, urethra, epididymis 2) external genitalia: penis, scrotum, testes 3) accessory glands: seminal, prostate, bulbourethral

Question 369

testes descent purpose

Answer 369

- for temperature regulation: sperm must be below body temp to be viable

Question 370

testes descent time

Answer 370

- between 3rd month of gestation and birth

Question 371

testes descent

Answer 371

- go from retroperitoneal position to external - descent from posterior abdominal wall into scrotum

Question 372

gubernaculum testes

Answer 372

- cord of CT and muscle fibers anchored to scrotum - does not elongate, eventually shortens - pulls testes through layers of abdominal wall (via inguinal canal)

Question 373

testes descent steps

Answer 373

1) testes anchored by gubernaculum to developing scrotum 2) pulled through abdominal wall during growth: deep inguinal ring formed passing through transversalis fascia 3) peritoneum evaginates at deep inguinal ring = processus vaginalis (does not pass through! only guides) 4) evagination continues through inguinal canal: superficial inguinal ring formed passing through external oblique aponeurosis 5) descent complete by birth: processes vaginalis closes off and forms tunica vaginalis

Question 374

inguinal canal

Answer 374

- between deep and superficial inguinal rings

Question 375

testes descent: layers of abdominal wall

Answer 375

1) does NOT pass through peritoneum 2) transversalis fascia 3) does NOT pass through transversus abdominis 4) internal oblique muscle 5) external oblique muscle/aponeurosis

Question 376

spermatic cord

Answer 376

- structures passing between abdominopelvic cavities and the testes and fascial coverings

Question 377

spermatic cord wall

Answer 377

1) external spermatic fascia 2) cremaster muscle (smooth) and fascia 3) internal spermatic fascia

Question 378

cremaster muscle function

Answer 378

- temperature control - contracts to bring testes closer when cold

Question 379

dartos muscle

Answer 379

- in superficial fascia under scrotum - temperature control: contracts to bring testes closer

Question 380

scrotum

Answer 380

- homologous to labia majora - covers testes

Question 381

spermatic cord contents

Answer 381

1) ductus deferens and artery to ductus deferens 2) testicular artery and pampiniform plexus 3) branch of genitofemoral nerve and autonomic nerves 4) lymphatics

Question 382

pampiniform plexus

Answer 382

- extensive vein network - cools blood entering into testes

Question 383

abdominal wall --> coverings of spermatic cord

Answer 383

1) peritoneum = tunica vaginalis 2) transversalis fascia = internal spermatic fascia 3) transversus abdominis muscle = nothing, not passed through 4) internal oblique muscle/fascia = cremasteric muscle/fascia 5) external oblique aponeurosis = external spermatic fascia 6) subcutaneous tissue = dartos fascia/muscle 7) skin = skin

Question 384

inguinal hernias

Answer 384

- weakened parts of abdominal wall result in protrusion of peritoneal sac - with or without abdominal contents ex. intestine

Question 385

indirect inguinal hernia

Answer 385

- peritoneal sac enters inguinal canal VIA deep inguinal ring - passes LATERAL to inferior epigastric vessels - cause: embryonic processus vaginalis remains open - commonly congenital

Question 386

direct inguinal hernias

Answer 386

- peritoneal sac enters inguinal canal DIRECTLY - passes MEDIAL to inferior epigastric vessels - cause: weakening in abdominal wall - commonly acquired

Question 387

cryptorchidism

Answer 387

- one or both testes fail to descend - higher proportion of inviable sperm produced

Question 388

testes structures

Answer 388

1) tunica vaginalis: serous membrane, parietal and visceral layers line scrotal cavity (containing serous fluid) 2) tunica albuginea: fibrous CT capsule, forms septa lobules 3) septa: subdivide internal space into lobules containing... 4) seminiferous tubules: blind end or loop, contain sustentacular and dividing germ cells 5) ducts: straight tubules --> rete testis --> efferent ductule, which goes to epididymis 6) raphe: ridge of tissue extending from anus to scrotum

Question 389

testes histology

Answer 389

1) outer tunica albuginea 2) seminiferous tubules 3) interstitial cells between = hormone production

Question 390

seminiferous tubules

Answer 390

- site of spermatogenesis - complex stratified epithelium containing sustentacular and spermatogenic cells

Question 391

sustentacular cells

Answer 391

- protection and nourishment for sperm cells - produce inhibit when sperm count is high (inhibits FSH secretion) - secured together by tight junctions = blood-testes barrier

Question 392

blood-testis barrier

Answer 392

- protects sperm from immune system

Question 393

interstitial cells

Answer 393

- produce androgens ex. testosterone - located between seminiferous tubules in loose CT along with BVs, nerves, lymphatics

Question 394

myoid cells

Answer 394

- unique contractile cells - expel contents of seminiferous tubules

Question 395

seminiferous tubule histology

Answer 395

1) myoid cells = outer edge, flattened nuclei 2) interstitial cells = outside 3) sustentacular cell = lighter stain, extend entire tubular wall 4) outer to inner (least to most mature): a) spermatogonium = dark nucleus b) primary spermatocyte = speckled c) secondary spermatocyte d) spermatid = smaller, not speckled e) spermatozoon = tails

Question 396

testes duct system function

Answer 396

- store sperm - transport sperm as they mature and pass out of the body (or die) - facilitate transport through smooth muscle stimulated by oxytocin

Question 397

testes duct system components

Answer 397

1) rete testes 2) efferent ductules 3) epididymis: head, body, tail 4) ductus deferens

Question 398

rete testis

Answer 398

- complex anastomotic network - simple cuboidal with microvilli - receive from straight tubule

Question 399

efferent ductules

Answer 399

- ciliated and non-ciliated columnar - absorb excess fluid secreted by seminiferous tubules

Question 400

epididymis function

Answer 400

- accumulation, storage and maturation (learn to swim) of sperm - uptake and digestion of luminal fluid and degenerated sperm

Question 401

epididymis structure

Answer 401

- highly coiled tube - pseudostratified columnar epithelium with LONG microvilli ("sterocilia") - principal cells = tall, columnar - basal cells = small, round - circular layer of smooth muscle

Question 402

ductus deferens structure

Answer 402

- thick-walled tube within spermatic cord - connects epididymis to prostatic urethra - ends at large ampulla (posterior to bladder) - unites with proximal seminal vesicle to form ejaculatory duct - empties into prostatic urethra (common with urine)

Question 403

ductus deferens layers

Answer 403

1) mucosa: pseudostratified columnar with few stereocilia + lamina propria 2) muscularis: inner longitudinal, middle circular, outer longitudinal 3) adventitia

Question 404

accessory gland general functions

Answer 404

- produce/secrete ~95% of seminal fluid to support sperm survival - smooth muscle contraction with SyNS during emission

Question 405

accessory glands specific functions

Answer 405

1) seminal vesicle/gland: secretions with fructose for energy 2) prostate gland: multiple ducts that secrete milky, nutrient rich fluid 3) bulbourethral glands: clear, viscous mucin for lubrication

Question 406

accessory gland locations

Answer 406

1) seminal: lateral to vas deferens, empty into ejaculatory duct 2) prostate gland: around prostatic urethra 3) bulbourethral: embedded in urogenital diaphragm, empty into membranous/spongy urethra

Question 407

perineum

Answer 407

- diamond-shaped area between thighs - inferior to pelvic diaphragm - consists of: 1) urogenital triangle: pubis symphysis, ischiopubic rami to ischial tuberosities 2) anal triangle: ischial tuberosities and coccyx

Question 408

urogenital triangle components

Answer 408

1) base of penis and scrotum OR clitoris 2) urethral and/or vaginal orifices 3) perineal membrane 4) skeletal muscles around external genitalia

Question 409

anal triangle components

Answer 409

1) anus

Question 410

penis function

Answer 410

- conduct urine and semen

Question 411

penis structure

Answer 411

1) bulb connects to body 2) crus of penis: attaches to perineum 3) root: fixed portion in urogenital triangle 4) body: suspended from pubic symphysis 5) glans: expanded, cap-like end of corpus spongiosum (covered by prepuce in uncircumcised person) 6) three parallel erectile columns: homologous to clitoris

Question 412

penis erectile columns

Answer 412

1) bilateral corpora cavernosa: dorsal (anatomical position = erect), surrounded by tunica albuginea 2) corpus spongiosum: ventral, containing spongy urethra * all encased in fascia and skin

Question 413

corpus cavernosa relative anatomy

Answer 413

- diverge as crura of penis - fuse to ischiopubic rami - covered by ischiocavernosus

Question 414

corpus spongiosum relative anatomy

Answer 414

- expands as bulb of penis - fuses to underside of perineal membrane - covered by bulbospongiosus

Question 415

perineal muscles in male

Answer 415

- skeletal - ischiocavernosus and bulbospongiosus

Question 416

penis blood supply

Answer 416

1) internal iliac artery 2) branches to dorsal and deep arteries 3) deep arteries branch and open into cavernous spaces of erectile tissue 4) arteriovenous anastomoses between deep artery branches and deep dorsal vein

Question 417

erectile tissue structure

Answer 417

- vascular spaces with smooth muscle and elastic CT trabeculae

Question 418

erection

Answer 418

- PSyNS relaxes trabecular and vascular smooth muscles - tunica albuginea limits filling of cavernous spaces = compression of dorsal veins traps blood

Question 419

emission

Answer 419

- SyNS input = peristalsis in ductus deferens and accessory glands

Question 420

ejaculation

Answer 420

- reflexive somatic input = rhythmic contraction of striated muscle surrounding bulb and crura of penis

Question 421

female reproductive system components

Answer 421

1) two ovaries 2) uterine tube 3) uterus 4) peritoneum creates recesses: vesicouterine and rectouterine pouches 5) external genitalia: mons pubis, clitoris, labia minora/majora 6) vagina 7) vestibule

Question 422

descent of ovaries

Answer 422

1) ovaries anchored by gubernaculum 2) growth causes ovaries to descend to pelvic brim (stays internal) 3) portion of gubernaculum attaches to uterus, splits to form: ovarian and round ligaments

Question 423

ovary/uterus ligaments

Answer 423

1) ovarian: ovary to uterus 2) round: uterus to labia majora, travels through inguinal canal 3) broad: drape of peritoneum where anterior and posterior layers connect, connects to ovary at hilum 4) suspensory: ovarian to pelvic wall, contains ovarian BVs, nerves and lymphatics

Question 424

ovaries

Answer 424

- paired, oval - anchored by specific cords and sheets of CT - no peritoneum, in peritoneal cavity

Question 425

ovary and uterine tube connection

Answer 425

- not directly connected - space between

Question 426

broad ligament contents

Answer 426

- subdivisions contain VANs, lymphatics

Question 427

ovary histology

Answer 427

outer to inner: 1) germinal (surface) epithelium: simple cuboidal (mesothelium) 2) tunica albuginea: dense irregular CT 3) cortex: contains ovarian follicles 4) medulla: areolar CT, BVs, Ls, Ns

Question 428

oogenesis

Answer 428

- production of primordial germ cells begins before birth (halted in prophase I = primary oocyte)

Question 429

atresia

Answer 429

- primordial germ cells degenerating throughout childhood (programmed cell death)

Question 430

ovarian cycle

Answer 430

- post puberty - monthly sequence of follicular development regulated by GnRH (affects FSH and LH levels) - follicular (1-14) and luteal phase (15-28)

Question 431

follicular pahse

Answer 431

- stimulated by increasing FSH - primordial follicles (many) --> primary --> secondary --> mature (primary oocyte differentiates into secondary and polar body)

Question 432

primordial follicle

Answer 432

- primary oocyte - simple squamous follicle cells - outer surface has thin basal lamina

Question 433

primary follicle

Answer 433

- simple cuboidal cells that undergo stratification to form granulosa layer (uni to multilaminar) - surrounding stroma (CT + smooth muscle) forms thecal layers (interna and externa) - zona pellucida around primary oocyte

Question 434

zona pellucida

Answer 434

- protective acellular layer around oocyte - contains sperm receptors - "clear"

Question 435

which cells secrete estrogen precursors?

Answer 435

- granulosa - theca interna

Question 436

secondary follicle

Answer 436

- primary oocyte - many granulosa cell layers - follicular fluid accumulates = become one continuous space = antrum - granulosa cells form cumulus oophorus: attaches oocyte to follicular wall - corona radiata: cells of CO that immediately surround oocyte

Question 437

mature follicle

Answer 437

- one predominant follicle - extends thickness of cortex - antrum increases in size - stratum granulosa thins - oocyte and cumulus cells loosen from surrounding granulosum = prep for ovulation - thecal cells become more prominent - secondary oocyte halted in meiosis II until fertilized

Question 438

fate of immature follicles

Answer 438

- atresia (majority)

Question 439

luteal phase

Answer 439

- remaining granulosa cells + theca interna of ruptured follicle = corpus luteum, secretes progesterone and estrogens to prepare uterine lining for implantation

Question 440

ovulation

Answer 440

- surge of LH causes release of secondary oocyte into peritoneal cavity

Question 441

corpus luteum vs granulosa/theca interna cells

Answer 441

- increase in size, fill with lipids

Question 442

end of luteal phase if no sperm

Answer 442

- corpus albicans = dense CT scar from degenerating corpus luteum - estrogen and progesterone decrease = uterine lining shed

Question 443

end of luteal phase if there is sperm

Answer 443

- secondary oocyte fertilized, may implant in uterine wall - pre-embryo produces human chorionic gonadotropic (hCG) hormone - hCG maintains corpus luteum, which continues to secrete progesterone - after 3 months: placenta takes over, corpus luteum degenerates

Question 444

polycystic ovary disease

Answer 444

- multiple follicular cysts - thickness of tunica albuginea prevents ovulation of mature follicle

Question 445

uterine tube structure

Answer 445

1) uterine part 2) isthmus 3) ampulla: expanded region where fertilization typically occurs 4) infundibulum: funnel-like area with fimbriae that sweep secondary oocyte into tube

Question 446

uterine tube histology

Answer 446

1) columnar (ciliated and non-ciliated) epithelium 2) lamina propria 3) smooth muscle: inner circular, outer longitudinal 4) serosa

Question 447

uterus support

Answer 447

- thick, muscular wall - pelvic floor (inferior) - ligaments: cardinal (transverse cervical), uterosacral, round

Question 448

uterus epithelium

Answer 448

- simple columnar - transitions to stratified squamous nonkeratinized passing through cervix and vagina

Question 449

uterus structure

Answer 449

1) fundus 2) body with uterine cavity 3) isthmus: narrowing 4) cervical canal

Question 450

internal/external os

Answer 450

1) internal = cervical opening from uterus (simple columnar to simple cuboidal) 2) external = cervical opening to vagina (simple cuboidal to stratified squamous nonkeratinized)

Question 451

cardinal (transverse cervical) ligaments

Answer 451

- under broad ligament - cervix to pelvic wall - prevents inferior movement of uterus

Question 452

uterosacral ligament

Answer 452

- attaches to sacrum (posterior side of uterus) - restricts inferior and anterior movement of uterus

Question 453

round ligament of uterus

Answer 453

- anterior side - attaches to external genitalia - prevents inferior and posterior movement of uterus

Question 454

prolapse

Answer 454

- weakness of pelvic floor and/or ligaments causes uterus to fall through into vagina - varying degrees

Question 455

uterine wall layers

Answer 455

1) perimetrium: outer, mostly serosa, continuous with broad ligament 2) myometrium: middle, 3 concentric layers of smooth muscle 3) endometrium: innermost mucosa = simple columnar (some ciliated, others secretory) + lamina propria (with uterine glands)

Question 456

uterine wall blood supply

Answer 456

1) branch from internal iliac artery (from aorta --> 2x common iliac --> internal) 2) uterine artery 3) arcuate artery = myometrium 4) radial artery = myometrium 5) straight artery = basal layer of endometrium 6) spiral artery = functional layer of endometrium

Question 457

endometrium layers

Answer 457

1) basal: highly cellular lamina propria, uterine glands 2) functional: sparser (spongier) lamina propria, more ground substance, includes most of length of glands and superficial epithelium --> lost during menstruation

Question 458

menstruation mechanism

Answer 458

- spiral arteries retract - functional endometrium loses blood supply

Question 459

uterine cycle

Answer 459

- cyclical changes to endometrial lining under influence of estrogens and progesterone 1-7 = menstrual phase ~10 = proliferative ~14 = secretory

Question 460

inhibin in females

Answer 460

produced by granulosa cells, inhibits FSH production

Question 461

menstrual phase

Answer 461

- triggered by decreasing progesterone and estrogen - spiral arteries contract, superficial becomes ischemic - degeneration and sloughing of functional layer

Question 462

proliferative phase

Answer 462

- increasing estrogen from developing follicles - cellular proliferation to regenerate functional layer (uterine epithelium, glands and spiral arteries) - glands secrete glycogen and rich mucus

Question 463

secretory phase

Answer 463

- begins after ovulation, persists as long as corpus luteum is intact - stimulated by progesterone and estrogen from corpus luteum - glands enlarge and accelerate secretion rate

Question 464

vagina structure

Answer 464

- fibromuscular tube with three layers: 1) mucosa: stratified squamous nonkeratinized + lamina propria 2) muscular layer (thinner than uterus) 3) adventitia - greater vestibular glands around vestibule: area between labia minora

Question 465

vagina acidic environment

Answer 465

- discourages bacterial growth - necessitates buffering capacity of seminal fluid

Question 466

vagina connections

Answer 466

- vaginal canal connects cervix to external environment

Question 467

urogenital triangle in females

Answer 467

- covered by perineal membrane - provides attachment for erectile tissue of external genitalia (vulva)

Question 468

female external genitalia arrangement

Answer 468

1) mons pubis = skin and adipose tissue 2) labia majora = paired thickened folds of skin, homologous to scrotum 3) labia minora = paired folds, no hair, more medial than majora 4) vestibule: contains urethral (anterior) and vaginal openings

Question 469

female erectile tissue

Answer 469

1) clitoris: crura, body, glans = homologous to penis 2) bulbs of vestibule: bilateral, deep to vestibule, connected to clitoris, homologous to bulb of penis

Question 470

perineal muscles in female

Answer 470

- bulbospongiosus over bulbs of vestibule - ischiocavernosus over crura of clitoris - propel blood into body and glans of clitoris - skeletal muscle