Anatomy Flashcards
Which are the two main arteries for blood supply to brain?
Internal carotid and Vertebral
Where do the internal carotid arteries begin?
Bifurcation of common carotid at C4
What arteries does internal carotid give rise to?
Ophthalmic
Posterior communicating
Anterior choroidal
Anterior cerebral
What does internal carotid become?
Middle cerebral to supply lateral cerebrum
What arteries do the vertebral arteries give rise to?
Meningeal branch to supply falx cerebelli
Ant/Post spinal
PICA
What do the vertebral arteries converge to form?
Basilar
Where do the vertebral arteries arise from?
Subclavian
What is the blood brain barrier?
Selectively permeable membrane to regulate molecules passing from blood to CNS
What makes up the BBB to make it effective?
Tight junctions in endothelial cells
No fenestrations in basement membrane
Pericytes wrap around endothelial cells and regulate cap flow, immunity and permeability
Astrocyte end feet restrict molecule flow
What percentage do internal carotid and vertebral supply to brain?
IC- 80%
Vertebral- 20%
Where does anterior cerebral supply?
Anteromedial aspects of brain
Where does posterior cerebral supply?
Posterior part of brain
Where does middle cerebral supply?
Majority of lateral brain
Which arteries supply the spine?
Anterior spinal
2x posterior spinal
Purpose of dural venous sinuses?
Drain blood from brain into jugular vein
What are the unpaired DVS?
Superior and inferior sagittal
Straight
Occipital
What are the paired DVS?
Transverse
Sigmoid
Petrosals
Cavernous
Pathway of CSF flow
Choroid plexus
Lateral ventricles
3rd ventricle via interventricular foramen
4th ventricle via cerebral aqueduct
Spinal cord or subarachnoid cisterns
What lines the choroid plexus?
Ependymal cells
What are the functions of CSF?
Protection
Buoyancy
Keeps environment chemically stable
Which notch is in the superior border of the manubrium?
Jugular
What articulates with what at the sternoclavicular joint?
Manubrium and clavicle
Which ribs articulate with the sternal body?
2-7
Which rib articulates with the xiphoid process?
7
What joint articulates rib to costal cartilage?
costochondral
What joint articulates ribs to sternum?
sternocostal
Which ribs are the true ribs?
1-7
Which ribs are the false ribs?
8-10
Which ribs are the floating ribs?
11-12
What is the joint where ribs articulate posteriorly with thoracic vertebrae?
costovertebral
How are adjacent ribs connected?
intercostal muscles
Which ribs are typical?
3-9
What are the features of typical ribs?
Head
Neck
Tubercle
Body
Which ribs are atypical?
1
2
10
11
12
Which part of the rib articulates with the vertebral body?
Head
Which part of the rib articulates with the transverse process?
Tubercle
What forms the boundary of the superior thoracic aperture?
Manubrium, first ribs and first T vertebra
What is the superior thoracic aperture?
Passageway for structures between neck and thorax
What is a dermatome?
Area of skin innervated by a single spinal nerve
Which dermatome is belly button in?
T10
Which part of breast tissue extends towards axilla?
Axillary tail
Why can’t you study the breast tissue in female cadavers?
Atrophies after menopause
What does the breast contain?
Fat
Glandular/ secretory tissue
Ducts
Areola (pigmented area)
Connective tissue and ligaments
Blood vessels and lymphatics
What is the arterial supply to the breast?
Internal thoracic (gives rise to anterior intercostals) and axillary arteries
Which nerves supply the breast?
Somatic and sympathetic fibres via intercostal nerves
Where does majority of lymph from breast drain?
Axillary lymph nodes
What are the 5 groups of lymph nodes in the axilla?
Central
Pectoral
Humeral
Subscapular
Apical
What drains into the axillary lymph nodes?
Breast
Upper limb
Chest wall
Scapulary region
Abdominal wall
Which of the 5 axilla nodes receives lymph from the other 4?
Apical
What are the 3 layers of muscles in the intercostal space?
External intercostal
Internal intercostal
Innermost intercostal
Where does pectoralis major attach?
The most superficial muscle of anterior chest wall
Attaches to the upper humerus, clavicle and upper 6 ribs
Where does pectoralis minor attach and where is it found?
Deep to pec major
Attaches to scapula and ribs 3-5
Where does serratus anterior attach and where is it found?
Found around lateral aspect of T cage
Attaches to scapula and ribs 1-8
What are the accessory muscles of breathing?
Pec major and minor
Serratus anterior
How are the external intercostal muscles orientated?
Antero-inferiorly
When is ext intercostal most active?
Inspiration as pulls the ribs superiorly
When is internal intercostal most active?
Expiration as pulls the ribs inferiorly
How do internal intercostal muscles run?
Perpendicular to external
Postero-inferior
Where is the endothoracic fascia found?
Deep to innermost intercostal and superficial to parietal pleura
Where is the neurovascular bundle in each intercostal space?
Between internal and innermost intercostal
Along inferior border of the rib superior to the space in a shallow groove
In the neurovascular bundle for the intercostal spaces which arteries are present?
Anterior intercostal from internal thoracic
Posterior intercostal from descending aorta
Where do the anterior and posterior intercostal veins drain?
Anterior: internal thoracic vein
Posterior: Azygos system
What are the intercostal nerves and what do they innervate?
Somatic
Contain motor, sensory and sympathetic
Innervate intercostal muscles, skin of chest wall and parietal pleura
What does the parietal pleura line?
Inside of thorax
What does the visceral pleura cover?
Surface of lungs and extends into fissures
What are the 4 parts of the parietal pleura?
Cervical (covers apex)
Costal (adjacent to ribs)
Mediastinal (adjacent to heart)
Diaphragmatic (adjacent to diaphragm)
What are the costodiaphragmatic and costomediastinal recesses?
Potential spaces for the lungs to expand into during deep inspiration
What innervates the parietal pleura and what does its pain feel like?
Intercostal nerves
Conscious and painful
What innervates the visceral pleura and what does the pain feel like?
Autonomic sensory nerves (visceral afferents)
Doesn’t reach conscious perception
How many lobes in the right lung and what are they?
3
Superior, middle, inferior
How many lobes in the left lung and what are they?
2
Superior + lingula (over heart), inferior
What does the oblique fissure separate in the lungs?
L: superior and inferior lobes
R: superior and middle from the inferior
What does the horizontal fissure in the right lung separate?
Superior from middle lobes
What enters the lungs at the hilum?
Pulmonary artery, veins and main bronchus
Where is the main bronchus in relation to the PA at the R and L hila?
L hilum: inferior to PA
R hilum: posterior to PA
PV usually most anterior and inferior vessels
At what level does the trachea bifurcate?
Sternal angle
How does the bronchial tree divide?
Main bronchus
Lobar bronchi (2-3)
Segmental bronchi (10) supplying a bronchopulmonary segment
Bronchioles
What is in the walls of the trachea and bronchi?
Smooth muscle and cartilage
What is in the walls of bronchioles?
Smooth muscle
Which arteries supply the lungs?
Bronchial + PA
Where do bronchial veins drain?
Azygos system
What do parasympathetic nerves in the lungs stimulate?
Bronchoconstriction
Gland secretion
What do sympathetic fibres in the lungs stimulate?
Bronchodilation
Inhibit secretion from glands
Where does lymph from the lungs drain?
Venous system via thoracic duct or R lymphatic duct
Surface anatomy markings of inferior border of lungs
6th rib anteriorly
8th rib laterally
10th rib posteriorly
Surface anatomy markings of parietal pleura
8th rib anteriorly
10th rib laterally
12th rib posteriorly
Surface anatomy of the oblique fissure
4th rib posteriorly to 6th costal cartilage anteriorly
Surface anatomy of the horizontal fissure
R
4th costal cartilage
Intersects oblique
What is the diaphragm?
A broad thin domed sheet of skeletal muscle
Central tendon in middle is fibrous
Separates thoracic and abdominal cavities
Has openings for structures to pass through
Integral to breathing
What is the diaphragm attached to?
Xiphoid process
Costal margin
Lumbar vertebrae
What happens to diaphragm during inspiration?
Contracts
Domes flatten as muscles pulled to peripheral attachments
Increases intrathoracic volume
What happens to diaphragm during expiration?
Relaxes and domes
Decreases intrathoracic volume
Pushes air from lungs
What innervates the diaphragm?
Phrenic nerves from C3,4,5
Motor and sensory
What does pleural fluid do?
Increase surface tension between parietal pleura and visceral pleura
This keeps the walls together so lungs change volume with cavities
What are the accessory muscles in breathing?
Pecs
Serratus anterior
Sternocleidomastoid
What does the mediastinum contain?
All thoracic viscera except lungs
What is found in the mediastinum?
Heart and pericardium
Great vessels
Trachea and main bronchi
Oesophagus
Nerves
Lymphatics
Veins that drain chest wall
Thymus gland
Where is the anterior mediastinum?
Posterior to sternum
Anterior to pericardial sac
Contains thymus gland in kids
What does the middle mediastinum contain?
Heart inside the pericardial sac
Pulmonary trunk
Ascending aorta
Where is the posterior mediastinum?
Between posterior aspect of pericardial sac and vertebrae
What does the superior mediastinum contain?
Arch of aorta
SVC
Trachea and oesphagus
Phrenic and vagus nerves
Thoracic duct
Thymus gland
What does the ascending aorta give rise to?
Coronary arteries to supply myocardium
What are the branches of the aortic arch?
Brachiocephalic trunk bifurcates into RCC and R subclavian
LCC
L subclavian
What do the R and L common carotid supply?
Head, neck, brain
When in the aorta are aortic bodies and chemoreceptors?
Aortic arch
How do chemoreceptors in aorta bring information back to CNS?
Vagus nerve
What is ligamentum arteriosum?
Fibrous cord connection between pulmonary trunk and aortic arch
Remnants of the ductus arteriosus
In the foetus what does the ductus arteriosus do?
Diverts blood entering pulmonary trunk to aortic arch
Closes when baby uses lungs at birth
What does the SVC do?
Returns blood from head, neck and upper limbs
What forms the SVC?
R and L brachiocephalic veins
What forms the brachiocephalic veins?
Internal jugular and subclavian
Where does the trachea terminate?
Sternal angle
T4-5
How do phrenic nerves enter the thorax?
Superior thoracic aperture
Where does the L recurrent laryngeal nerve run?
Loops under aortic arch then ascends back up alongside trachea
Where does the R recurrent laryngeal nerve run?
Descends down anterior R subclavian artery
Loops under artery then ascends between trachea and oesophagus
What does the vagus nerve give parasymp fibres to?
Heart, lungs and oesophagus
Most of abdominal viscera
Where does the thoracic duct empty?
Venous system at union of L internal jugular vein and L subclavian vein
What is the pericardium?
Tough, fibrous sac that encloses the heart
Has a visceral and parietal layer, with pericardial cavity in the middle
Innervated by branches of phrenic
Which surface of the heart is the L atrium?
Posterior
Which surface of the heart is the L and part of R ventricle?
Inferior
Which surface of the heart is the R ventricle?
Anterior
Where is the left ventricle of heart?
L pulmonary surface
Where is the R atrium on the heart?
R pulmonary surface
Surface landmarks of R border of heart
R 3rd costal cortilage to 6th
Surface landmarks of the L border of heart
L 2nd to 5th intercostal space in midclavicular line
What is a tuberosity?
large rounded projection
What is a crest?
narrow ridge of bone, usually prominent
What is a trochanter?
very large, blunt, irregularly shaped process
What is a tubercle?
small rounded projection or process
What is a foramen?
round or oval opening through bone
What is a meatus?
Canal
What is a fossa?
shallow, basinlike depression in a bone
What do the coronary arteries arise from?
Ascending aorta
Where do cardiac veins return blood to?
Coronary sinus which enters R atrium
What do the RCA and its branches supply?
Parts of conducting system
R atrium and ventricle
Part of L ventricle
Part of interventricular septum
What are the main branches of the RCA?
Branches to SAN and AVN supplying conducting system
R marginal artery supplying inferior border
Posterior interventricular artery
Where does the posterior interventricular artery run and supply?
Continuation of RCA
Runs in the posterior IV sulcus on inferior diaphragmatic surface
Supplies both ventricles
What does the LCA supply?
Parts of the conducting system
L atrium
Most of L ventricle
Part of R ventricle
Part of interventricular septum
What is the part of the LCA called before it divides?
Left main stem
What are the 2 large terminal branches of the LCA?
LAD (anterior interventricular artery)
Circumflex
What do the main branches of the LCA supply?
LAD: anterior interventricular sulcus towards apex supplying both Ventricles
Circumflex: onto inferior surface supplying L atrium, part of R ventricle and L ventricle
L marginal: from circumflex, supplies L ventricle
What determines dominance in the heart?
Whether the posterior interventricular artery arises from L or R coronary artery
Most R dominant
What does R dominance mean in the heart?
PIV arises from RCA
Both R and LCAs supply the L ventricle
What does L dominance in the heart mean?
PIV arises from circumflex
LCA supplies the entire L ventricle
So an occlusion of L main stem would cut off entire L ventricle
What do valves inside the heart ensure?
Unidirectional flow of blood through chambers of heart
What does the R atrium receive?
Deoxygenated blood from body via SVC/IVC
Deoxygenated blood from heart via coronary sinus
What does the interatrial septum separate?
R and L atria
In the R atrium
What is the fossa ovalis?
A depression in the interatrial septum
Remnant of foramen ovale
In the R atrium
What is the foramen ovale?
In foetus shunts oxygenated blood from the right atrium to the left, bypassing lungs
What is the crista terminalis?
A muscular ridge that separates the smooth walled posterior part of atrium from the anterior part (ridged wall)
Parts of the R atrium on either side have different embryological structures
What and where are the pectinate muscles in the heart?
parallel muscular columns that are present on the inner wall of the right and left atria
What valve separates R atrium and ventricle?
R atrioventricular
Tricuspid
What does the R ventricle do?
Pump deoxygenated blood into pulmonary trunk
Where is the pulmonary valve?
At entrance to pulmonary trunk to stop backflow of blood into R ventricle
What are some internal features of the R ventricle?
Interventricualr septum
Trabeculae carneae
Papillary muscles
Chordae tendinae
Moderator band
What does the interventricular septum separate?
The ventricles of heart
What are trabeculae carneae?
Muscular ridges on internal ventricle wall
What do the papillary muscles of the heart do?
attach to the cusps of the atrioventricular valves via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole
What are chordae tendineae?
Fibrous cords which connect tips of the papillary muscles to the AV valves in the ventricles
What does the moderator band in the ventricles do?
Connects interventricular septum to one of the papillary muscles
What does the L atrium receive?
Oxygenated blood from lungs via 4 pulmonary veins
What valve separates L atrium and ventricle?
Mitral
Where is the aortic valve?
At entrance to the aorta
Prevents backflow
How do the papillary muscles influence the AV valves?
Allow closed valves to resist pressure
Pressure in ventricles rises, valves close passively
Ventricles contract, papillary muscles also contract and tense the cords
Pull on valves and stop them from everting into atria
Which are the semilunar valves?
Aortic and pulmonary
Which valves in the heart are tricuspid?
All but mitral
What rate does the SAN generate impulses?
70 per minute
What do the left and right bundle branches give rise to?
Purkinje fibres
What supplies the SAN?
RCA in 60% of people
LCA in 40%
What supplies the AVN?
Posterior interventricular artery
What supplies the bundle of His?
LCA
Where can referred pain from the heart be felt?
Chest
L side of neck and arm
What does the posterior mediastinum contain?
Descending aorta
Azygos veins
Oesophagus
Thoracic duct
Symp trunk and splanchnic nerves
Posterior intercostal vessels and nerves
What are the branches of the descending aorta?
Posterior intercostal - supply intercostal spaces
Bronchial - supply lungs
Oesophageal - supply oesophagus
Pericardial branches - supply pericardium
Phrenic - supply diaphragm
At what level does the aorta pass through the diaphragm?
T12
At what level does the azygos system of veins arise?
L1/L2 in abdomen
What does the azygos system of veins drain?
Posterior thoracic wall to SVC
Posterior intercostals
Oesophageal
Bronchial
Where are the azygos veins?
In the body of T vertebrae
What does the azygos venous system comprise of?
Azygos vein on R side of vertebral bodies
Smaller hemiazygos vein on L side
One or more connecting veins
What is the arterial supply to the oesophagus?
Oesophageal arteries
At what level is the oesophageal hiatus in the diaphragm?
T10
Where does the thoracic duct lie?
Between azygos vein and aorta
What does the thoracic duct do?
Drains most of body’s lymph to venous system
Where does lymph from lower limbs, pelvis and abdomen go?
Cisterna chyli which gives rise to thoracic duct
Where does the thoracic duct terminate?
Empties into the venous system at junction between internal jugular and subclavian
What does the thoracic duct drain upper body?
Intercostal spaces and lymph nodes
L head and neck
L upper limb
What is a ganglion?
Collection of cell bodies outside the CNS
What are the abdominopelvic splanchnic nerves?
Greater and lesser splanchnic
Least splanchnic
Lumbar splanchnic
Where does the greater splanchnic nerve originate from?
T5-9
Where does the lesser splanchnic nerve originate from?
T10-T11
Where does the least splanchnic nerve originate from?
T12
Where do the lumbar splanchnic nerves originate from?
L1-2
Where are the greater, lesser and least splanchnic nerves formed?
Posterior mediastinum
What does the posterior intercostal space contain?
Intercostal muscles
A posterior intercostal artery, vein and nerve
Vein drains into azygos
What innervates the thoracic viscera?
Cardiopulmonary splanchnic convey postganglionic sympathetic fibres to the thoracic viscera
Vagus conveys parasymp
Together these form autonomic plexuses
What autonomic plexuses are found in the thorax?
Cardiac plexus
Pulmonary plexus
Oesophageal plexus
What does the cardiac plexus innervate?
SAN
Does heart rate
What does the pulmonary plexus innervate?
Bronchi
What does the oesophageal plexus innervate
Overlies the anterior surface of oesophagus
Symp inhibit peristalsis
Parasymp stimulate peristalsis
How do visceral afferents relay sensory information from viscera back to CNS?
Along vagus and thoracic splanchnic
How does cardiac referred pain work?
Visceral sensory and autonomic from heart enters at T1-T5
Somatic sensory from skin of chest wall, neck and arm enter T1-5
Brain interprets cardiac pain as coming from these regions
What is platysma?
Very thin subcutaneous muscle deep to skin of neck
How many cervical vertebrae are there?
7
Articulate with each other at facet joints
What is the hyoid bone?
Slender bone anteriorly in upper neck
Inferior to mandible
Helps keep pharynx open
What is the larynx?
Skeleton of small cartilages connected by membranes and small joints
Protects airway
Muscles attach to laryngeal cartilages and move them
Voice box
What separates the anterior and posterior triangles in the neck?
Sternocleidomastoid
What does the sternocleidomastoid attach to?
Sternum, clavicle, mastoid process of temporal bone
What innervates the sternocleidomastoid muscle?
Accessory (CN 11)
What are the boundaries of the anterior triangle?
Anterior: midline of neck
Posteriorly: anterior border of sternocleidomastoid
Superiorly: lower border of mandible
What does the anterior triangle contain?
Trachea
Larynx
Thyroid and Parathyroid glands
Submandibular salivary gland
Suprahyoid muscles
Infrahyoid muscles
Common carotid artery
Branches of external carotid artery
Internal jugular vein
Branches of CN VII, IX,X, XI, XII nerves
Ansa cervicalis
What is the ansa cervicalis?
Fibres from C1-C3 which innervate infrahyoid muscles
What do the suprahyoid muscles do?
Connect hyoid to skull
Form floor of mouth
Move hyoid and larynx superiorly in speech and swallowing
What do the infrahyoid muscles do?
Connect hyoid to sternum and scapula
Move hyoid and larynx inferiorly in speech and swallowing
What are the boundaries of the posterior triangle?
Anteriorly: posterior border of sternoCM
Posteriorly anterior border of trapezius
Inferiorly: clavicle
Superior apex formed by SCM and trapezius
What does the posterior triangle contain?
Muscles that move head
Part of subclavian artery and vein
External jugular vein
Accessory nerve
Roots of brachial plexus
Cervical plexus (C1-4)
Phrenic nerve
What are the 4 suprahyoid muscles?
All paired
Mylohyoid
Geniohyoid
Stylohyoid
Digastric
What are the 4 infrahyoid muscles?
All paired
Sternohyoid and omohyoid superficial
Sternothyroid and thyrohyoid depp
Where is the thyroid gland?
Composed of R and L lobes lateral to lower larynx
Lobes deep to sternothyroid muscle
Lobes joined by isthmus
What is the blood supply to the thyroid gland?
L and R superior thyroid arteries from ext carotid
L and R inferior thyroid from subclavian branches
Drained by thyroid veins
Where are the parathyroid glands and what do they do?
4: R and L superior and inferior
Posterior to thyroid
Produce PTH
Supplied by inferior thyroid
What do the common carotid bifurcate into?
Internal and external carotid
What does external carotid supply?
Gives rise to branches that supply neck, head, pharynx, scalp, thyroid gland, tongue and face
Where is the carotid sinus?
Point of bifurcation of common carotid
What is in the carotid sinus?
Baroreceptors which monitor arterial blood pressure
Relayed back to CNS via CN IX
What gives rise to the inferior thyroid artery?
Thyrocervical trunk
What forms the brachiocephalic vein?
Internal jugular and subclavian veins
What drains face and scalp?
External jugular vein
What nerve supplies platysma?
Facial nerve
What does glossopharyngeal nerve supply in the neck?
Pharynx for sensory info
Carotid sinus
What does vagus nerve supply in the neck?
Muscles of pharynx
Larynx (motor and sensory)
Where does the vagus nerve run in the neck?
Between internal jugular vein and internal carotid artery (above bifurcation)
Between internal jugular vein and common carotid artery (below bifurcation)
3 structures run together in fascial sleeve (carotid sheath)
What does accessory nerve supply in the neck?
SternoCM
Trapezius
What does hypoglossal nerve supply in the face and where does it run?
Motor muscles of tongue
Travels through neck but doesn’t supply it
Lateral to internal carotid
Deep to external jugular vein
What is the pharynx?
A muscular tube that forms part of the resp and GI systems
What makes up the walls of the pharynx?
Outer layer of circular muscle
Inner layer of longitudinal muscle
What muscles are in the external circular layer of the pharynx wall?
3 constrictor muscles: superior, middle and inferior
Contract so that swallowed food moves down
How does swallowing work?
Food in oral cavity pushed into oropharynx by tongue
Soft palate rises and closes off naso
Food enters laryngopharynx
Constriction of muscles in wall move food down oesophagus
Epiglottis closes off laryngeal inlet
What is the sensory innervation to the pharynx?
Glossopharyngeal
What is the motor innervation to the pharynx?
Vagus
What nerves lie close to the posterior pharyngeal wall?
Cervical sympathetic trunk
Superior laryngeal
Hypoglossal nerve
Glossopharyngeal
What is the function of the larynx?
Protects airway
Contributes to phonation and speech
How many cartilages make up the laryngeal skeleton? And what connects them?
9
3 paired and 3 unpaired
Membranes and very small joints connect the cartilages to each other
What are the 3 unpaired cartilages of the larynx?
epiglottis
thyroid
cricoid
What are the 3 paired cartilages of the larynx?
Arytenoids
Cuneiforms
Corniculates
All much smaller than the unpaired
What forms the laryngeal prominence?
Two flat cartilages of the thyroid cartilages meet anteriorly to form adams apple
What are the superior and inferior horns of the laryngeal skeleton?
Posterior projections of laminae from thyroid cartilage
Superior horns attach to hyoid bone
Inferior horns articulate with cricoid
What does the cricothyroid membrane connect?
Inferior border of thyroid and superior border of the cricoid
This is what is pierced for emergency airway
Where is the epiglottis attached and what does it do?
Attached to superior aspect of thyroid cartilage where laminae meet
Covers entrance to larynx during swallowing to protect airway
Where are the arytenoid cartilages?
Superior surface of cricoid cartilage
Articulate with cricoid at small joints
What do the arytenoid cartilages do?
Movement of vocal cords which attach to them
Vital for phonation
What are the extrinsic muscles acting on the larynx?
Suprahyoid and infrahyoid
Move the larynx as one, not individual cartilages
What do the intrinsic cartilages acting on the larynx move?
Individual cartilages
Move the vocal cords altering the quality of speech
What are tonsils?
Collections of lymphoid tissue in upper parts of the pharynx
What tonsils are found in the nasopharynx?
Pharyngeal in roof of nasopharynx
Tubal surrounds opening of auditory tube
Which tonsils are found in the oropharynx?
Palatine and lingual
What are the 2 folds in the larynx?
Vestibular superiorly
Vocal folds inferiorly
What forms the true vocal cords?
Vocal folds and vocal ligaments
Space between cords is the rima glottidis
What opens and closes the rima glottidis?
Adduction of true vocal cords closes it
Abductions opens
What does phonation require?
Adduction of cords and closure of the rima glottidis
When is the rima glottidis open?
Small degree in whispering
Partially in breathing
Fully in forced breathing
What are some of the intrinsic muscles of the larynx?
Cricothyroid
Posterior cricoarytenoids (abduct vocal cords and open rima glottidis)
Transverse arytenoids (adduct vocal folds and close RG)
What innervates the cricothyroid muscle?
Superior laryngeal from vagus
Also provides sensory to larynx above vocal folds
What innervates the intrinsic muscles of larynx (except cricothyroid)?
Recurrent laryngeal from vagus
Also provides sensory to larynx below the vocal folds
What salivary glands secrete saliva into oral cavity?
Parotid
Submandibular
Sublingual
All paired
Where does the parotid gland open?
Adjacent to upper second molar
What stimulates secretion from parotid?
Parasympathetic fibres in glossopharyngeal
What is close to the parotid gland?
Facial nerve enters deep into parotid and divides into 5 branches
Close to external carotid
Where does the submandibular duct open?
Into floor of the mouth under the tongue
Stimulated by facial nerve
Where do the sublingual glands open?
Via several small ducts into the floor of the mouth
Stimulated by facial nerve
What does the abdominal cavity contain?
GI tract
Hepatobiliary system
Urinary system
Endocrine system
Spleen
Great vessels
What are the walls of the abdomen composed of?
Skin
Subcutaneous tissue
Muscles and associated aponeuroses
What are the functions of the abdo wall?
Protect viscera
Increase intra-abdominal pressure (defecation, childbirth)
Maintain pressure and move trunk
What lines the internal aspect of the abdominal wall?
Parietal peritoneum
What are the 4 quadrants?
R and L upper
R and L lower
What are the 9 regions?
R hypochondrium
Epigastrium
L hypochondrium
R lumbar region
Umbilical region
L lumbar region
R iliac fossa
Hypogastric region
L iliac fossa
What lines divide the abdomen into regions?
Midclavicular
Subcostal
Intertubercular
Where is the transpyloric plane?
A horizontal line that passes through the tips of the R and L 9th costal cartilages
Halfway between superior manubrium and pubic symphysis
Transects pylorus of stomach, gallbladder, pancreas and hila of kidneys
Where is the transumbilical plane?
Approx at L3 but varies depending on amount of subcutaneous fat
Unreliable
Where is the intercristal plane?
Horizontal line drawn between highest points of R and L iliac crests
Not palpable anteriorly
Used for lumbar puncture guidance
Where is McBurney’s point?
2/3 along line from umbilicus to R ASIS
What are the 4 pairs of muscles that comprise anterolateral abdominal wall?
External oblique
Internal oblique
Transversus abdominis
Rectus abdominis
What is rectus abdominis attached to?
Sternum and costal margin superiorly
Pubis inferiorly
Surrounded by rectus sheath
How are ext ob, int oblique and transversus abdominis layered?
External oblique most superficical
Internal oblique deep to EO
TA deep to IO
What is an aponeurosis?
Flat tendon
What do the aponeuroses of EO, IO and TA form?
Linea alba and the rectus sheath
What forms the rectus sheath?
Aponeuroses of EO and anterior IO form anterior wall
Aponeuroses of TA and posterior IO form posterior wall of rectus sheath
What lies deep to transversus abdominis?
Transversalis fascia
Deep to that is parietal peritoneum
What is the blood supply to the anterolateral abdo wall?
Musculophrenic artery from internal thoracic
Superior epigastric (continuation of internal thoracic)
Inferior epigastric from external iliac, anastomoses with sup epig
What is the innervation to the anterior abdo wall?
Thoraco-abdominal nerves (T7-T11), motor and sensory
Subcostal (T12)
Iliohypogastric and ilioinguinal from L1
What is peritoneum?
A serous membrane that line abdo wall and covers viscera
What is pain from parietal peritoneum like?
Sharp, well localised, severe
What is pain from the visceral peritoneum like?
Usually dull and diffuse so can’t be pinpointed to a specific location
Often perceived as nausea or distension
Can be severe
Where is the peritoneal cavity and what is its purpose?
Between parietal and visceral peritoneum
Filled with peritoneal fluid
Allows viscera to slide freely alongside each other
What does intraperitoneal mean?
Almost completely covered by peritoneum
What does retroperitoneal mean?
Posterior to peritoneum, only covered on anterior surface
What are mesenteries?
Folds of peritoneum that contain fat
suspend small intestine and parts of large from posterior abdo wall
Arteries for intestine and veins from gut embedded in mesenteries
What are the omenta?
Folds of peritoneum that are usually fatty
Connect stomach to other organs
Where is the greater omentum?
Hangs from greater curvature of stomach and lies superficial to SI
Where is the lesser omentum?
Connects stomach and duodenum to liver
Hepatic artery, hep portal vein and bile duct in its free edge
What are abdo ligaments?
Folds of peritoneum that connect organs to each other or the abdo wall
Where is the median umbilical fold and what is it the remnant of?
In the midline and represents remnant of the urachus
Where are the medial umbilical folds and what are they the remnants of?
Lateral to median umbilical fold
Remnant of paired umbilical arteries which return venous blood to placenta in foetal life
Where are the lateral umbilical folds?
Lateral to medial umbilical folds
superficial to inf epig arteries
Where is the smaller lesser sac?
Space posterior to stomach and anterior to pancreas
Where is the greater sac?
all of peritoneal cavity that isn’t lesser sac
How do the greater and lesser sacs communicate with each other?
Epiploic foramen
What do the muscles around the oesophageal hiatus function as?
A sphincter to prevent reflux of stomach contents into oesophagus
What supplies the distal oesophagus?
Branches from left gastric
What is the venous drainage of the oesophagus?
oesophageal veins that drain into azygos
left gastric veins that drain into portal venous system
What is the distal oesophagus a site of?
Portosystemic anastomoses
What is food broken down into?
Chyme
What does the oesophagus continue into in the stomach?
The cardia of the stomach
What is the most superior part of the stomach?
The fundus, usually filled with gas
What is the largest part of the stomach called?
Body
What makes up the pyloric part of the stomach?
Pyloric antrum
Pyloric canal
Pyloric sphincter
What does the pyloric sphincter regulate?
Regulates passage of chyme into duodenum
Where are the curvatures of the stomach?
Lesser curvature on R border
Greater curvature on L border
What quadrant is the stomach in?
Left upper
What covers the stomach?
Visceral peritoneum
What is the anterior surface of the stomach related to?
Anterior abdominal wall
Diaphragm
L lobe of liver
What does the posterior surface of the stomach form?
Anterior wall of the lesser sac
What connects the lesser curvature to the liver?
Lesser omentum
What does the free edge of the lesser omentum contain?
Hepatic artery
Hepatic portal vein
Bile duct
Where does the greater omentum hang from?
Greater curvature
What is the coeliac trunk?
Large unpaired vessel that leaves the anterior aspect of abdominal aorta to supply abdominal viscera
What is the coeliac trunk derived form?
Foregut
What comprises the foregut?
Stomach
First half of the duodenum
Liver
Gallbladder
Pancreas
What is the spleen from?
Mesoderm
What does the coeliac trunk divide into?
L gastric artery
Common hepatic artery
Splenic artery
Where do the L and R gastric arteries run along?
Lesser curvature of stomach
Anastamose with each other
Where does the L gastric artery arise from?
Coeliac trunk
Where does the R gastric artery arise from?
Common hepatic
Where do the gastro-omental arteries arise from and run?
L arises from splenic
R arises from gastrodudenal artery
What do the gastric and gastro-omental veins drain into?
Hepatic portal vein
What does the hepatic portal vein do?
Carries nutrient-rich venous blood from GI tract to liver
What innervates the stomach?
Vagus- parasymp promoting peristalsis and gastric secretion
Greater splanchnic- symp, T5-9, inhibit peristalsis
What are the 3 parts of the small intestine?
Duodenum
Jejunum
Ileum
What is the major duodenal papilla?
The opening of the bile duct and main pancreatic duct into the duodenum
Halfway along the internal wall of the duodenum
What is the duodenum derived from?
first half from foregut
second half from midgut
Which parts of the small intestine are intraperitoneal and what are they derived from?
Jejunum and ilieum
Midgut
Where are the jejunum and ileum?
Suspended from the posterior abdo wall by the mesentery of the small intestine
Jejunum in left upper region
Ileum in right upper region
What is the histology of the jejunum and ileum?
Sites of nutrient absorption
Vast surface area
Mucosa folded: plicae circulares (more pronounced in jejunum)
Villi and microvilli on epithelia
What is meckel’s diverticulum?
Embryological remnant of connection between midgut loop and yolk sac
Blind-ended diverticulum in ileum
What makes up the large intestine?
Caecum
Appendix
Ascending, transverse, descending and sigmoid colon
Rectum
Anal canal
What are some features of the large intestine?
Have taeniae coli running longitudinally (3 muscle bands)
Inner muscular layer forms haustra (bulges)
Bears fatty tags callled epiploic appendages
What do epiploic appendages mark?
The point at which blood vessels penetrate the intestinal wall
What is the caecum?
The first part of the large intestine
Covered by peritoneum
No mesentery
Appendix arises from caecum
What connects the appendix to the caecum?
Small mesentery called mesoappendix
What is the ascending colon continuous with and where does it run?
Continuous with caecum
Runs vertically on R side of posterior abdo wall in R paracolic gutter
Retroperitoneal
What is the hepatic flexure?
The bend in the colon where ascending becomes continuous with transverse
Where does the transverse colon run?
horizontally in the upper abdomen
often hangs inferiorly
Intrapritoneal
Suspended from the posterior abdo wall by transverse mesocolon
What is the splenic flexure?
Bend in colon where transverse becomes descending
Tethered to diaphragm by phrenicocolic ligament
Where is the transition between the midgut and hindgut?
Proximal 2/3 of the transverse colon midgut
Final 1/3 hindgut
Means transverse parts are supplied by different vessels
Where does the descending colon run?
Vertically on the left side of the posterior abdo wall
In left paracolic gutter
Retroperitoneal
What is the rectosigmoid junction?
sigmoid colon makes 90 degree bend into pelvis
Where is the sigmoid colon?
Sinuous shape
Continuous with desc colon and rectum
Intraperitoneal as it has sigmoid mesocolon
Where is the rectum?
Descends inferiorly into pelvis from rectosigmoid junction
Retroperitoneal
What are the 3 main arteries supplying the GI tract?
All unpaired
Coeliac trunk
Superior mesenteric artery
Inferior mesenteric artery
What supplies the foregut?
Branches from coeliac trunk
What supplies the midgut?
Superior mesenteric artery
Where does superior mesenteric leave the aorta and what does it supply?
L1
Midgut structures
Parts of the pancreas
What does the inferior mesenteric artery supply and where does it leave aorta?
Hindgut
L3
What are the major branches of superior mesenteric?
Jejunal to jejunum
Ileal to ileum
Ileocolic to caecum, appendix and asc colon
R colic to asc colon
Middle colic to trans colon
What do the ileal and jejunal branches of SMA form?
Embedded in the SI mesentery
Anastamose with each other
Form loops of arteries called arcades
From the arcades run the vasa recta
What are the vasa recta?
Supply the intestinal wall
Long straight arteries
From arcades
What are the major branches of the inferior mesenteric artery?
L colic to trans colon and desc colon
Sigmoid branches to sigmoid colon
Superior rectal (terminal branch) to upper rectum
What forms the marginal artery in the GI tract?
Branches of middle colic and left colic anastamose along distal 1/3 of trans colon and splenic flexure
How is blood drained from the gut?
Inferior mesenteric vein (drains hindgut) runs up left and drains into splenic
Superior mesenteric vein (drains midgut) and unites with splenic vein to form hepatic portal vein
Hepatic portal vein enters the liver
Nutrients removed, blood enters small hepatic veins which unite to form hepatic veins
IVC
What is the parasympathetic innervation to the midgut and foregut?
Vagus
What is the parasympathetic innervation to the hindgut?
Pelvic splanchnic nerves
The cell bodies of preganglionic PS lie in S2-S4
Synapse with a second neuron in ganglion very close to viscera
What do the splanchnic supply and do?
Greater: symp to foregut
Lesser: symp to midgut
Least: symp to hindgut
Inhibit peristalsi and secretions
Where does visceral sensory info from the gut enter spinal cord?
Foregut: T5-T9
Midgut: T10-T11
Hindgut: T12
Where is the liver?
Right upper quadrant
Epigastrium
Where is the diaphragmatic surface of the liver?
Anterosuperior
Related to inferior surface of diaphragm
Where is the visceral surface of the liver?
Poasteroinferior
Related to other organs
Which parts of the liver are not covered by visceral peritoneum?
Bare area
Where gallbladder is in contact with liver
Porta hepatis
What separates the 2 anatomical lobes of the liver?
Falciform ligament
This connects anterior surface of the liver to internal anterior abdo wall
What are the 2 accessory lobes of the liver?
Caudate and quadrate lobes on the posteroinferior surface
What is the liver organised into internally?
8 functional segments
All served by their own branch of hep artery, portal vein and hep duct
How does blood get from coeliac trunk to liver?
Coeliac trunk
Common hepatic arteries
Gastroduodenal branches off and CHA becomes hepatic artery proper
HAP bifurcates into R and L hepatic arteries
Enter at porta hepatis
How does venous blood leave the liver?
2 or 3 large hepatic veins that lie within liver
Unite with IVC posteriorly
What goes throught the hepatic portal vein?
Nutrient rich venous blood from gut into liver
Where does liver referred pain go?
Epigastrium
What is the nervous supply to the liver?
Hepatic plexus which has PS from vagus and symp
What connects the liver to the diaphragm?
Coronary and triangular ligaments
What connects the liver to the anterior abdo wall?
Falciform ligament
What connects the liver to the stomach and duodenum?
Lesser omentum
What makes up the portal triad and where does it run?
Hepatic artery
Hepatic portal vein
Bile duct
Run in free edge of lesser omentum
What forms the anterior border of epiploic foramen?
Portal triad and free edge of lesser omentum
What are the 2 recesses related to the liver?
Hepatorenal: between R kidney and posterior R liver
L and R subphrenic recesses: either side of falciform ligament
What does the liver develop from?
Foregut
What is the round ligament of the liver?
Remnant of umbilical vein
In free edge of falciform ligament
What is the ligamentum venosum a remnant of?
Ductus venosus
What does the gallbladder do?
Stores and concentrates bile
Lies posteroinferior surface of liver
What are the 3 parts of the gallbladder?
Fundus
Body
Neck
What is the surface marking of the gallbladder fundus?
Tip of 9th costal cartilage where midclavicular line intersects R costal margin
What is the path of bile?
Hepatocytes
Excreted into bile canaliculi
Drain into bile ducts eventually R and L hepatic ducts
Exit at porta hepatis
Converge to form common hepatic duct
Receives from cystic
Forms common bile duct which enters duodenum
Where does bile from the liver go if its not needed for digestion?
Gallbladder via cystic duct
Where is the spiral fold?
Junction between gallbladder neck and cystic duct
What supplies and drains the gallbladder?
Cystic artery
Cystic veins directly into liver or via HPV
What innervates the gallbladder?
Parasympathetic and symp
Visceral pain enters spinal cord at T5-T9
Where is gallbladder referred pain felt?
Epigastrium
R shoulder if irritates diaphragm
R hypochondrium if irritates parietal peritoneum
Why can gallbladder pain be felt in R shoulder?
Irritates the diaphragm
C3,4,5 segments of spinal cord receive sensory info from skin over shoulder too
At what level does the coeliac trunk leave the aorta?
T12
What does the L gastric artery supply?
Distal oesophagus
Lesser curvature of stomach
What does the common hepatic artery supply?
Liver
Stomach
Duodenum
What does the splenic artery supply?
Stomach
Pancreas
Spleen
What are the 4 parts of the duodenum?
Superior (first)
Descending (second)
Inferior (third)
Ascending (fourth)
What is the posterior to the superior part of the duodenum?
Bile duct
Gastroduodenal aratery
Hepatic portal vein
What is anterior to the inferior (third) part of duodenum?
Superior mesenteric artery
What is it called where the ascending duodenum and jejunum meet?
Duodenaljejunal flexure
What supplies the first part of the duodenum?
Branches of coeliac trunk: gastroduodenal artery
Why does the duodenum have different blood supplies?
First half is foregut
Second half is midgut
What supplies the second half of the duodenum?
Branches of SMA: inferior pancreaticoduodenal
What level does the pancreas lie at?
L1
Retroperitoneal
What are the 4 parts of the pancreas?
Head (cupped by duodenum)
Neck
Body
Tail (extends to hilum of spleen)
What is the ucinate process on the pancreas?
Hook-like projection on head
Where in the pancreas is the splenic artery?
Embedded in upper border
Where does the splenic vein lie?
Posterior to pancreas
What is the function of the pancreas?
Endocrine: synthesises and secrets insulin and glucagon
Exocrine: produces pancreatic juice that contains digestive enzymes
What ducts are in the pancreas that can transport pancreatic juice into duodenum?
Main pancreatic duct
Accessory pancreatic duct
What merges at the hepatopancreatic ampulla?
Bile duct and main pancreatic duct
What surrounds the hepatopancreatic ampulla?
Smooth muscle called the sphincter of Oddi
What does contraction of the sphincter of Oddi do?
Prevents reflux of duodenal contents into bile and main pancreatic ducts
Where does the accessory duct empty pancreatic juice into duodenum?
Minor duodenal papilla
Proximal to major
Where does the hepatopancreatic ampulla open into?
Major duodenal papilla in descending duodenum
What is teh blood supply to the pancreas?
Splenic from coeliac trunk
Superior pancreaticoduodenal from gastroduodenal
Inferior pancreaticoduodenal from SMA
Where is the spleen?
L upper quadrant
Protected by ribs 9-11
What does the spleen do?
Breaksdown old RBCs
Stores RBCs and platelts
Immune response_ production of IgG
What are the 2 surfaces and 4 borders of the spleen?
Diaphragmatic surface
Visceral surface in contact with stomach, L kidney and colon, where hilum is
Anterior and superior notched borders
Posterior and inferior smooth borders
Is the spleen palpable?
No
If it is then it is badly enlarged
What is the blood supply to the spleen?
Splenic artery
Drained by splenic vein
What separates the L and R nasal cavities?
Midline septum
What separates nasal and oral cavities?
Hard palate
What forms the posterior septum in nose?
Superior post: ethmoid bone
Inferior post: vomer
What are the 3 projections of bone in the lateral wall of nasal cavity?
Turbinates (superior, middle, inferior)
What separates the nasal cavity from the brain?
Cribriform plate
Olfactory neurons pass through
Where in the nasal cavity are olfactory receptors located?
Spheno-ethmoial recess in upper nasal cavity
What are the 4 paranasal sinuses?
Frontal in frontal bone
Ethmoid in ethmoid bone (superior to nasal cavity, medial to orbits)
Sphenoid in sphenoid bone (near pituitary)
Maxillary in maxillae of facial skeleton
Where does the frontal sinus drain?
Middle meatus
Where does the sphenoid sinus drain?
Spheno-ethmoidal recess
Where do the ethmoid air cells drain?
Superior and middle meatuses
Where does the maxillary sinus drain?
Middle meatus
Why can’t maxillary sinus drain when upright?
Opening of sinus into middle meatus lies superomedially
What does the nasolacrimal duct drain?
Fluid that lubricate the anterior surface of eye
Drains into nasal cavity
Why do you get a runny nose when you cry?
Excess fluid runs down nasolacrimal duct into inferior meatus in nasal cavity
What does the eustachian tube connect?
Middle ear to nasopharynx
Allos air to pass into middle ear so pressure on either side of eardrum is equal
What is the blood supply to the nasal cavity?
Maxillary artery from external carotid
Anastomotic network supply nasal septum which is often where bleeding from nosebleeds comes from
What is the sensory innervation of the nose?
Trigeminal
What 2 bones composes the hard palate?
Palatine bone of maxilla
Horizontal plate of palatine bone
What does the hard palate do?
Prevents food or fluid entering nasal cavity
Forces food backwards when tongue pushes against it
Articulate certain sounds
Where does the uvula hang?
Midline of soft palate
What do the muscles of the soft palate do?
Contract during swallowing to elevate soft palate
Innervated by vagus
What are the boundaries of the oral cavity?
Superior: palates
Inferior: soft tissues and muscles
Laterally: cheeks containing buccinator muscle
What does the oral cavity contain?
Tongue
Teeth
Gums
Openings of salivary glands
How many teeth do adults have and where are they?
32
16 in maxilla
16 in mandible
What are the different types of teeth?
in upper and lower jaw:
4 incisors
2 canines
4 premolars
6 molars
What are teeth composed of?
An inner pulp surrounding blood vessels and nerves
Dentin surrounding pulp
Outer hard enamel coat
What can happen to enamel and dentin?
Eroded by bacteria or food
Leading to decay, inflammation and infection of pulp
May spread to bone causing abscess
Where is the tongue?
Anteriorly in oral cavitiy
Posteriorly in oropharynx
What is the space between the posterior tongue and epiglottis called?
Vallecula
What is on the superior surface of the tongue?
Papillae
Some detect taste
Where are the intrinsic muscles of the tongue and what do they do?
Within tongue
Paired bilaterally
Fuse in midline
Change shape of tongue
Where are the extrinsic muscles of the tongue and what do they do?
Originate from outside the tongue but attach to it
Move the tongue
What innervates the tongue muscles?
Hypoglossal (CN 12)
What is the sensory innervation to the tongue?
Taste in front 2/3: facial
General sensation in front 2/3: trigeminal
Taste and general sensation in back 1/3: glossopharyngeal
What is the blood supply to the oral cavitiy?
Lingual, maxillary, facial arteries from external carotid
What innervates the muscles of the soft palate?
Vagus
What 4 CN innervate the tongue?
V, VII, IX, XII
(trigeminal, facial, hypoglossal, glossopharyngeal)
Where are the pharyngeal tonsils?
In roof and posterior wall of nasopharynx
Where are the tubal tonsils?
Surround the opening of the auditory tube on lateral wall of nasopharynx
Where are the palatine tonsils?
Lateral wall of oropharynx
Where are the lingual tonsils?
A collection of lymphoid tissue in posterior tongue
Differences between jejunum and ileum
Jejunum in upper left quadrant, ileum lower R
Jejunum has a thicker wall and longer vasa recta
Jejunum has less arcardes
Jejunum is red in colour, ileum is pink
ileum has peyers patches
What are the 3 histological types of joints?
Synovial
Fibrous
Cartilagnious
What is the structure of synovial joints?
Narrow synovial cavity separates articular surfaces
Synovial fluid in cavity
Joint capsule: outer fibrous and inner synovial membrane
Hyaline cartilage
Allow great deal of movement
Examples of synovial joints?
Shoulder
Knee
Wrist
Sturcture of fibrous joints
2 bones connected by strong fibrous tissue
No cavity
No fluid
Very little movement
E.g. skull sutures
What are primary cartilaginous joints?
Hyaline cartilage connects joints
Allows some flexibility
E.g. where ribs meet sternum
What are secondary cartilaginous joints?
Connected to each other by fibrocartilage
Hyaline cartilage covers articular surfaces of bones
Flexible but strong
E.g. intervertebral discs in spine
What are the 6 types of synovial joints?
Ball and socket
Hinge
Pivot
Saddle
Condyloid
Plane
Example of ball and socket joints
Hip
Shoulder
Example of hinge joint
Elbow
Knee
Example of pivot joint
Between C1 and C2
Example of saddle joint
Carpometacarpal in thumb
Example of a condyloid joint
Wrist
Metacarpophalangeal
Example of plane joint
Joints between small wrist bones
Acromioclavicular joint
What makes up grey matter?
Neuron cell bodies
What makes up white matter?
Axons
At what level does the spinal cord end?
L1-L2
Features of the sympathetic nervous system neurons
First neuron cell body in T or L spine
Short preganglionic axon
Second neuron cell body in ganglion close to CNS
Long postganglionic axon
Features of PS neurons
1st neuron cell body in brainstem or sacral spinal cord
Long preganglionic axon
Second neuron cell body in ganglion close to target organ
Short postganglionic axon
How many spinal nerves are there and how are they distributed?
31
8 C
12 T
5 L
5 S
1 Co
