Heart

Question 1

location of heart

Answer 1

middle mediastinum division of the inferior mediastinum

Question 2

contents of middle mediastinum

Answer 2

pericardium, heart, origins of great vessels, nn, smaller vessels

Question 3

layers of pericardium

Answer 3

1. outer fibers pericardium (inelastic CT)
2. thin serous pericardium (1. parietal part lines inner surface of fibrous pericardium, 2. visceral part firmly adheres to outer surface of heart as epicardium

Question 4

embryologic origins of parietal and visceral parts of serous pericardium

Answer 4

parietal: somatic mesoderm
visceral: splanchnic mesoderm

Question 5

layers of heart wall

Answer 5

1. epicardium: visceral layer of serous pericardium
2. myocardium: muscle
3. endocardium: 1 cell layer thick, lines chambers

Question 6

what takes up most of anterior surface of heart

Answer 6

R ventricle

Question 7

valves and septa

Answer 7

• AV valves
• semilunar valves: aortic and pulmonary
• interatrial septum
• interventricular septum

Question 8

RA

Answer 8

• smooth wall=sinus venosis
• auricle (roof)=rough w/ pectinate muscle
• crista terminalis: vert ridge separating smooth from rough part
• fossa ovalis: remnant of foramen ovale in IA wall
• receives deoxy blood from SVC, IVC, and coronary sinus

Question 9

R AV valve

Answer 9

• tricuspid
• anchored via chorda tendinae to papillary m
• ant, post, and septal cusps

Question 10

R ventricle

Answer 10

• interior wall is rough with trabeculae carneae
• moderator band: medially, part of conduction system
• conus arteriosus (infundibulum): funnel to pulm tr

Question 11

pulm semilunar valve

Answer 11

• at apex of infundibulum

- 3 cusps: L, R, ant

Question 12

L atrium

Answer 12

• 4 pulm vv enter posteriorly

- receives oxy blood from lungs via pulm vv

Question 13

L AV valve

Answer 13

-and and post cusps

Question 14

L vent

Answer 14

• much thicker wall than R
• most of post surface
• aortic orifice: leads into ascending aorta
• no moderator band*

Question 15

aortic semilunar valve

Answer 15

L, R, and post cusps

Question 16

cardiac skeleton

Answer 16

• composed of dense collagen rings (4, valves of heart), and trigones
• provides attachment, support, and insulation

Question 17

ascultation points

Answer 17

R AV: 5th space, left sternal border
L AV: 5th space, midclav line
aortic: 2nd space, R side of sternum
pulm: 2nd space, L side of sternum

Question 18

coronary vasculature

Answer 18

• R and L coronary aa come directly from aorta

- most vv drain to coronary sinus, then RA

Question 19

R coronary a

Answer 19

• supplies R A and V, SA node, AV node, IA septum, L atrium, post inf 1/3 IV septum, post portion LV
• travels in coronary sulcus
• brs: ant R atrial a, SA nodal a, R marginal, post IV a (if R dominant)

Question 20

L coronary a

Answer 20

• supplies most of LA, LV, IV septum

- brs: ant IV a (LAD), circumflex a (gives L marginal)

Question 21

venous drainage via coronary sinus

Answer 21

• drains to RA
  1. great cardiac v: ant IV a
  2. middle cardiac v: post IV a
  3. small cardiac v: R marginal a

Question 22

ant cardiac vv

Answer 22

• do not empty into coronary sinus

- travels with ant RV aa

Question 23

bypass grafts

Answer 23

commonly use

1. great saphenous v
2. int thor a
3. radial a

Question 24

nerve supply of heart

Answer 24

• own conduction system
• ANS affects rate (symp innervation from TI-T5, parasymp innervation from vagus n)
• doesnt require CNS initiation
• normal 70 bpm

Question 25

what contributes to superficial and deep cardiac plexuses of nn

Answer 25

symp and parasymp innervation

*superficial is ant to heart

Question 26

conduction system

Answer 26

SA node - AV node - bundle of His - bundle brs - purkinje fibers