[USMLE] Heart Summary

Question 1

The base of the heart is formed by the

Answer 1

atria that lie behind the ventricles

Question 2

The apex of the heart lies in the

Answer 2

left fifth intercostal space slightly medial to the midclavicular (or nipple) line

Question 3

location is for auscultating the mitral valve

Answer 3

left fifth intercostal space

Question 4

crista terminalis

Answer 4

is a vertical muscular ridge running anteriorly along the right atrial wall from the opening of the SVC to the opening of the IVC, providing the origin of the pectinate muscles.

Question 5

crista terminalis presents the junction between the

Answer 5

primitive sinus venarum and the right atrium proper

Question 6

crista terminalis is indicated externally by the

Answer 6

sulcus terminalis

Question 7

left vs right atrium

Answer 7

The left atrium is smaller and has thicker walls than the right atrium

Question 8

left atrium

Answer 8

the most posterior of the four chambers

Question 9

The left ventricle forms the

Answer 9

heart’s apex

Question 10

left vs right ventricle

Answer 10

performs harder work, has a thicker wall, and is more conical-shaped than the right ventricle.

Question 11

The papillary muscles contract to tighten the

Answer 11

chordae tendineae

Question 12

an isolated band of trabeculae carneae that forms a bridge between the interventricular septum and the base of the anterior papillary muscle of the right ventricle

Answer 12

septomarginal trabecula (moderator band)

Question 13

septomarginal trabecula (moderator band) carries the

Answer 13

right limb (Purkinje fibers) of the AV bundle

Question 14

the first heart sound is caused by the

Answer 14

closure of the tricuspid and mitral valves at the

onset of ventricular systole

Question 15

the second heart sound is caused by the

Answer 15

closure of the aortic and pulmonary valves and vibration of walls of the heart and major vessels at the onset of
ventricular diastole

Question 16

most audible over the right lower part of the body of the sternum

Answer 16

tricuspid (right AV) valve

Question 17

most audible over the apical region of the heart

in the left fifth intercostal space at the midclavicular line

Answer 17

bicuspid or mitral (left AV) valve

Question 18

most audible over the left second intercostal space just lateral to the sternum

Answer 18

pulmonary valve

Question 19

most audible over the right second intercostal space just lateral to the sternum

Answer 19

aortic valve

Question 20

the pacemaker

Answer 20

SA node

Question 21

The SA node (pacemaker) lies in the

Answer 21

myocardium at the upper end of the crista terminalis and initiates the heartbeat

Question 22

Impulse travels from the

Answer 22

SA node through the atrial myocardium to the AV node that lies in the interatrial septum and then to the AV bundle (of His) that runs along the membranous part of the IV septum, right and left bundle branches that descend into the muscular part of the IV septum, terminal conducting fibers (Purkinje fibers), and the ventricular musculature.

Question 23

These arteries arise from the ascending aorta

Answer 23

coronary arteries

Question 24

coronary arteries have maximal blood flow during diastole and

Answer 24

diastole

Question 25

coronary arteries have minimal blood flow during

Answer 25

systole (because of compression of the arterial branches in the myocardium during systole)

Question 26

The right coronary artery gives off the

Answer 26

sinuatrial nodal, marginal, posterior IV, and AV nodal

arteries

Question 27

The left coronary artery is shorter than the right one and divides into the

Answer 27

anterior IV and circumflex arteries

Question 28

All cardiac veins , including the great, middle, small, and oblique cardiac veins, drain into the

Answer 28

coronary sinus except the anterior cardiac vein

Question 29

the anterior cardiac vein drains into the

Answer 29

right atrium

Question 30

formed by the union of the right ascending lumbar and right subcostal veins. Its lower end is connected to the IVC.

Answer 30

azygos vein

Question 31

the azygos vein arches over the

Answer 31

root of the right lung

Question 32

the azygos vein empties into the

Answer 32

SVC

Question 33

thoracic duct begins in the

Answer 33

abdomen at the cisterna chyli , which is the dilated junction of the intestinal, lumbar, and descending intercostal trunks

Question 34

thoracic duct drains all parts of the body except the

Answer 34

right head, neck, upper limb, and thorax

Question 35

the right head, neck, upper limb, and thorax are drained by the

Answer 35

right lymphatic duct

Question 36

the thoracic duct passes through the

Answer 36

aortic opening of the diaphragm, ascends between the aorta and the azygos vein

Question 37

the thoracic duct empties into the

Answer 37

junction of the left internal jugular and subclavian veins

Question 38

greater splanchnic nerve arises from the

Answer 38

fifth through ninth thoracic sympathetic ganglia and

Question 39

greater splanchnic nerve ends in the

Answer 39

celiac ganglion

Question 40

lesser splanchnic nerve arises from the

Answer 40

tenth and eleventh thoracic sympathetic ganglia

Question 41

lesser splanchnic nerve ends in the

Answer 41

aorticorenal ganglion

Question 42

least splanchnic nerve arises from the

Answer 42

twelfth thoracic sympathetic ganglia

Question 43

least splanchnic nerve in the

Answer 43

renal plexus

Question 44

All of these splanchnic nerves contain

Answer 44

preganglionic sympathetic GVE fibers and GVA fibers

Question 45

cell bodies of the preganglionic sympathetic GVE fibers are located in the

Answer 45

lateral horn (intermediolateral cell column) of the spinal cord

Question 46

cell bodies of GVA fibers are located in the

Answer 46

dorsal root ganglia

Question 47

contain preganglionic sympathetic GVE fibers with cell bodies located in the lateral horn of the spinal cord and GVA fibers with cell bodies located in the dorsal
root ganglia.

Answer 47

White rami communicantes

Question 48

White rami communicantes are connected to the spinal nerves and limited to the spinal cord segments between

Answer 48

T1 and L2

Question 49

contain postganglionic sympathetic GVE fibers with cell bodies located in the sympathetic chain ganglia

Answer 49

Gray rami communicantes

Question 50

Gray rami communicantes are connected to every spinal nerve and supply the

Answer 50

blood vessels, sweat glands, and arrector pili muscles of hair follicles