CVS anatomy pre-practical Flashcards
where does the mediastinum lie
between the right and left pleurae it extends from the sternum in front to the vertebral column behind
which thoracic organs does
all except the lungs
into how many parts is the mediastinum divided
2 - inferior and superior
into how many parts is the inferior mediastinum divided into and what are these relative to
3 - anterior, middle, posterior the pericardium middle contains the pericardium and its contents
what are the main contents of the superior mediastinum
glandular plane - thymus venous plane - brachiocephalic vein, SVC arterial - nervous plane - branch of aortic arch, vagus and phrenic nerve visceral plane - trachea, oesophagus lyphatic plane - thoracic duct
what is the vena cava formed from
the union of the 2 brachiocephalic veins
what does the anterior mediastinum contain
thymus lymph nodes fat
what are the main contents of the posterior mediastinum
oesophagus and vagus nerve azygos vein sympathetic trunk thoracic duct descending aorta splanchnic nerve
what are the 2 types of pericardia
fibrous and serous
describe the layers of the serous pericardium
outer parietal layer inner visceral layer = epicardium
what is the pericardial cavity
between parietal and visceral layers filled with fluid
what is the epicardium composed of
endothelial cells and a thin layer of fat and connective tissue
main identification features of the right atrium
openings for: IVC, SVC, coronary sinus interatrial septum fossa ovalis in septum musculi pectinati tricuspid valve
what is the fossa ovalis known as before birth and what is its function
foramen ovali allows blood to travel between the L and RA as the blood doesnt need to travel to the lungs hole closes up when the baby is born
main identification features of right ventricle
tricuspid valve (3 cusps, chordae tendineae, 3x papillary muscles) trabeculae carneae moderator band (septomarginal trabeculum) opening for the pulmonary trunk IV septum
what are trabeculae carneae
contractile fleshy struts surfactant for the ventricle allows the ventricle to re-expand following contraction prevents suction that would occur with flat surface and thus impair the heart’s ability to pump efficiently the papillary muscles are a specialised form of trabeculae carneae
what is the moderator band (septomarginal trabeculum)
one of the fleshy trabeculae that attaches to the anterior wall of the right ventricle and holds it together (wall is 3x thinner than the LV wall)
main identification features of the left atrium
openings for L+R sup pulmonary veins, L+R inf pulmonary veins bicuspid (mitral) valve smooth walled, small chamber, lies wholly posterio-superiorly against the oesophagus forms base of heat
main identification features of the left ventricle
bicuspid (mitral) valve ( 2 valve cusps, chordae tendinae, 2x papillary muscles) trabeculae carneae opening for aorta Interventricular septum wall 3x as thick as RV wall no need for moderator band forms apex of heart
which vertebrae does the heart lie opposite in the recumbent position
T5-8
where is the apex of the heart located
5th left intercostal space, mid-clavicular line left ventricle
where is the base of the heart
wholly posterior left atrium
where is the R border of the heart
SVC and right atrium
where is the left border of the heart
aortic arch and left ventricle
what forms the anterior surface of the heart
R atrium (1/4) R ventricle (1/2) L ventricle (1/4)
what are the main arteries, veins and lymphatics of the trunk and chest wall
internal thoracic artery - gives of anterior IC arteries internal thoracic vein - recieves anterior thoracic veins descending aorta inferior vena cava azygos vein thoracic duct
where do the IVC and SVC lie in relation to the aorta
to the R of it
main arteries of the upper limb
subclavian arises from aortic arch subclavian becomes axillary at lateral border of 1st rib axillary becomes brachial at inferior border of teres major muscle brachial divides into radial and ulnar in cubital fossa radial and ulnar form palmar arches in the palm of the hand which give off digital arteries
superficial veins of the upper limb
arise from the dorsal and venous arch on the back of the hand
cephalic travels up the limb on the lateral side, drains into axillary vein below clavicle
basilic travels up limb on medial side, becomes continuous with brachial veins (deep veins accompanying brachial artery)
median cubital connects cephalic and basilic across cubital fossa
main arteries of the lower limb
external iliac becomes common femoral in anterior thigh
common femoral gives off superficial and deep femoral arteries
superficial becomes popliteal in popliteal fossa
popliteal gives of anterior and posterior tibial in leg
posterior tibial gives of fibular (peroneal) and continues medially down to plantar surface of foot (medial and latral arteries)
anterior tibial continues down anteriorly to dorsum of foot where it becomes dorsalis pedis between 1st and 2nd toes
superficial veins of lower limb
superficial veins arise from dorsal arch of foot
long saphenous travels up the limb medially to drain into femoral
short saphenous travels up the limb posteriorly to drain into popliteal
popliteal becomes femoral proximally
femoral becomes external iliac proximally
superficial veins drain inot deep veins
superficial arterial pulse points of the body
superficial tempora and facial - branches of external carotid
common carotid - branch of aortic arch
brachial - continuation of axillary
radial - lateral branch of brachial
femoral - continuation of external iliac
popliteal - continuation of femoral
posterior tibial - branch of popliteal
dorsalis pedis - continuation of anterior tibial
coronary arterial supply of the heart
right coronary artery
left coronary artery
anastamoses - anterior and posterior descending, circumflex and RCA
right coronary artery
arises from R aortic sinus of ascending aorta
runs in coronary (AV sulcus)
at inferior margin of heart it gives off right marginal artery
on posterior surface of heart RCA gives of posterior descending aorta
LCA
arises from left aortic sinus of ascending aorta
runs in coronary sulcus
divides almost immediately into L anterior descening attery (in interventricular sulcus) and circumflex artery
coronary artery anastamoses
anterior and posterior descending
circumflex and RCA
occur on posterior surface of the heart
which 2 major sulci contain the branches of the coronary arteries
coronary (atrioventricular) sulcur - between atria and ventricles
interventricular sulcus - between L and R ventricles
which coronary artery is known as the artery of death
anterior interventricular artery
venous drainage of the heart
great cardiac vein lies alongside anterior interventricular artery
middle cardiac vein lies alongside posterior interventricular artery
small cardiac vein lies alongside right marginal artery
all above drain into the coronary sinus lying alongside the circumflex artery
the coronary sinus drains into the right atrium
anterior cardiac veins draind directly into the right atrium
what sets the rate of contraction of the heartthe
the inherent rate of contraction is set by a small group of specialised cardiac cells found in the SAN
this rate can be altered by the autonomic nervous system
what nerves innervate the heart
phrenic nerve
vagus nerve
sympathetic fibres
how does the phrenic nerve innervate the heart
innervates the fibrous pericardium and parietal layer of serous pericardium
carries pain sensation
how does the vagus nerve innervate the heart
innervates heart and visceral layer of serous pericardium
decreases heart rate
how do sympathetic fibres innervate the heart
from the cervical and upper thoracic sympathetic ganglia
innervate the the heart and visceral layer of serous pericardium
increase heart rate and force of contraction
internal innervation of the heart (conduction)
signals arising in the SAN stimulate the atria to contract and travel to the AVN
after a delay, the stimulus is conducted thorugh the bundle of his to L and R branches and Purkinje fibres to the endocarium at the apex of the heart then finally to the ventricular epicardium
