CVS anatomy pre-practical

Question 1

where does the mediastinum lie

Answer 1

between the right and left pleurae it extends from the sternum in front to the vertebral column behind

Question 2

which thoracic organs does

Answer 2

all except the lungs

Question 3

into how many parts is the mediastinum divided

Answer 3

2 - inferior and superior

Question 4

into how many parts is the inferior mediastinum divided into and what are these relative to

Answer 4

3 - anterior, middle, posterior the pericardium middle contains the pericardium and its contents

Question 5

what are the main contents of the superior mediastinum

Answer 5

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

Question 6

what is the vena cava formed from

Answer 6

the union of the 2 brachiocephalic veins

Question 7

what does the anterior mediastinum contain

Answer 7

thymus lymph nodes fat

Question 8

what are the main contents of the posterior mediastinum

Answer 8

oesophagus and vagus nerve azygos vein sympathetic trunk thoracic duct descending aorta splanchnic nerve

Question 9

what are the 2 types of pericardia

Answer 9

fibrous and serous

Question 10

describe the layers of the serous pericardium

Answer 10

outer parietal layer inner visceral layer = epicardium

Question 11

what is the pericardial cavity

Answer 11

between parietal and visceral layers filled with fluid

Question 12

what is the epicardium composed of

Answer 12

endothelial cells and a thin layer of fat and connective tissue

Question 13

main identification features of the right atrium

Answer 13

openings for: IVC, SVC, coronary sinus interatrial septum fossa ovalis in septum musculi pectinati tricuspid valve

Question 14

what is the fossa ovalis known as before birth and what is its function

Answer 14

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

Question 15

main identification features of right ventricle

Answer 15

tricuspid valve (3 cusps, chordae tendineae, 3x papillary muscles) trabeculae carneae moderator band (septomarginal trabeculum) opening for the pulmonary trunk IV septum

Question 16

what are trabeculae carneae

Answer 16

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

Question 17

what is the moderator band (septomarginal trabeculum)

Answer 17

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)

Question 18

main identification features of the left atrium

Answer 18

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

Question 19

main identification features of the left ventricle

Answer 19

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

Question 20

which vertebrae does the heart lie opposite in the recumbent position

Answer 20

T5-8

Question 21

where is the apex of the heart located

Answer 21

5th left intercostal space, mid-clavicular line left ventricle

Question 22

where is the base of the heart

Answer 22

wholly posterior left atrium

Question 23

where is the R border of the heart

Answer 23

SVC and right atrium

Question 24

where is the left border of the heart

Answer 24

aortic arch and left ventricle

Question 25

what forms the anterior surface of the heart

Answer 25

R atrium (1/4) R ventricle (1/2) L ventricle (1/4)

Question 26

what are the main arteries, veins and lymphatics of the trunk and chest wall

Answer 26

internal thoracic artery - gives of anterior IC arteries internal thoracic vein - recieves anterior thoracic veins descending aorta inferior vena cava azygos vein thoracic duct

Question 27

where do the IVC and SVC lie in relation to the aorta

Answer 27

to the R of it

Question 28

main arteries of the upper limb

Answer 28

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

Question 29

superficial veins of the upper limb

Answer 29

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

Question 30

main arteries of the lower limb

Answer 30

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

Question 31

superficial veins of lower limb

Answer 31

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

Question 32

superficial arterial pulse points of the body

Answer 32

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

Question 33

coronary arterial supply of the heart

Answer 33

right coronary artery left coronary artery anastamoses - anterior and posterior descending, circumflex and RCA

Question 34

right coronary artery

Answer 34

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

Question 35

LCA

Answer 35

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

Question 36

coronary artery anastamoses

Answer 36

anterior and posterior descending circumflex and RCA occur on posterior surface of the heart

Question 37

which 2 major sulci contain the branches of the coronary arteries

Answer 37

coronary (atrioventricular) sulcur - between atria and ventricles interventricular sulcus - between L and R ventricles

Question 38

which coronary artery is known as the artery of death

Answer 38

anterior interventricular artery

Question 39

venous drainage of the heart

Answer 39

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

Question 40

what sets the rate of contraction of the heartthe

Answer 40

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

Question 41

what nerves innervate the heart

Answer 41

phrenic nerve vagus nerve sympathetic fibres

Question 42

how does the phrenic nerve innervate the heart

Answer 42

innervates the fibrous pericardium and parietal layer of serous pericardium carries pain sensation

Question 43

how does the vagus nerve innervate the heart

Answer 43

innervates heart and visceral layer of serous pericardium decreases heart rate

Question 44

how do sympathetic fibres innervate the heart

Answer 44

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

Question 45

internal innervation of the heart (conduction)

Answer 45

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