ICL 1.1: Heart & Pericardium

Question 1

when does the heart start to beat?

Answer 1

23 days

Question 2

what is the pericardium?

Answer 2

double-walled fibroserous sac which surrounds and covers the heart and roots of great vessels

1. serous pericardium (visceral and parietal)
2. fibrous pericardium

Question 3

what are the 2 divisions oft the serous pericardium?

Answer 3

1. parietal layer = lines the inside of the fibrous pericardium
2. visceral layer covers the outside of the heart and has a special name = epicardium

Question 4

what is the fibrous pericardium?

Answer 4

connective tissue layer outside of the parietal serous layer that forms bulk of the gross pericardial sac

it’s fused to adjacent connective tissue planes

Question 5

what are the 2 pericardial sinuses?

Answer 5

1. oblique
2. transverse

slide 9

Question 6

what are the boundaries of the pericardium?

Answer 6

superiorly: fuses with adventitia of great vessels at level of the sternal angle
inferiorly: fuses with fascia of the diaphragm
laterally: fuses with mediastinal pleura
posteriorly: fuses with adventitia of esophagus –> the heart sits on the esophagus! the pericardium helps the heart not move and bounce around and crush the esophagus

Question 7

what is the blood supply of the pericardium?

Answer 7

1. pericardiacophrenic from internal thoracic**
2. musculophrenic
3. internal thoracic
4. esophageal aa. from aorta
5. bronchial aa.
6. pericardial – directly from aorta

Question 8

which nerve innervates the pericardium?

Answer 8

1. phrenic nerves
2. vagus nerves
3. sympathetic trunk

Question 9

what is the function of the pericardium?

Answer 9

the pericardium contains approximately 10 to 15 cc’s of serous fluid

the function of the pericardium is to limit or prevent acute pathological distension of the heart once the pericardial reserve volume has been used up and the pericardium is stretched

the pericardial attachments maintain the heart in its normal position and are so arranged that external forces exerted on the pericardium by respiration or changes in body posture tend to cancel each other and maintain a constant heart position

Question 10

what is cardiac tamponade?

Answer 10

the pericardial sac allows for the heart to have free movement within the pericardium

if there’s a bleed in the pericardium, the collection of blood in the pericardial sac is a limiting factor for the heart beating because the pericardium can only be stretched so much

so the heart will be confined and the ventricles won’t be able to expand all the way due to the pressure buildup and cardiac output will be reduced

Question 11

what are the layers of the heart wall?

Answer 11

1. epicardium = visceral layer of the pericardium; external covering of heart

subepicardium = between epicardium and muscles; contains fat and major vessels to the heart

2. myocardium = middle muscular layer; oblique fibers
3. endocardium = inner lining layer composed of endothelium backed by thin connective tissue

subendocardium = just outside the endocardium and contains tissues of the conducting system

Question 12

where is the apex of the heart?

Answer 12

5th intercostal space at the midclavicular line

Question 13

where is the base of the heart?

Answer 13

it’s where you see the aorta, pulmonary trunk and superior vena cava

Question 14

what are the various surfaces of the heart?

Answer 14

slide 20-23

Question 15

where is the left atrium?

Answer 15

on the posterior surface of the heart!!

it sits on the esophagus!!!!!!!

Question 16

where is the coronary sinus located?

Answer 16

between the left atrium and ventricle on the posterior surface of the heart

Question 17

what are the 4 valves of the heart?

Answer 17

1. tricuspid valve = right atrioventricular valve
2. mitral valve = left atrioventricular valve
3. pulmonary valve
4. aortic valve

Question 18

what is the tricuspid valve?

Answer 18

between the right atrium and right ventricle

Question 19

what is the mitral valve?

Answer 19

between the left atrium and left ventricle

Question 20

what is the pulmonary valve?

Answer 20

it closes the orifice of the pulmonary trunk, which consists of three semilunar valves, or cusps

Question 21

what is the aortic valve?

Answer 21

it closes the aorta and also consists of 3 semilunar valves or cusps

Question 22

what is the structure of the atrioventricular valves?

Answer 22

fibrous rings and chordae tendineae!

the chordae tendineae go from the valves and extend and attach to the papillary muscles

it’s like a parachute!

Question 23

what is the function of the infundibulum?

Answer 23

it funnels all the blood from the right ventricle into the pulmonary trunk

inFUNdibulum FUNnnels blood

aka conus arteriosus which developed from the bulbis cordis –> the pulmonary trunk develops from the conus arteriosus

Question 24

what are the semilunar valves?

Answer 24

the aortic and pulmonary valves!

right and left coronary artery openings are in the aortic valve along with the aortic sinus

Question 25

where do you listen for the semilunar valves?

Answer 25

the 2nd intercostal space

aortic valve is on the right while pulmonary is on the left

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Question 26

where do you listen to all the valves during a cardio exam?

Answer 26

there’s liquid flow of blood so when the sound is being propagated from the valve closing, the sound will follow the flow of the blood!! that’s why we listen to the valves in the spots that we do even though that’s not where the valve itself is

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Question 27

what are the generic heart sounds and what do they represent? like which valves are opening/closing at each?

Answer 27

lub = first sound (S1) closure of a-v valves (tricuspid and mitral)

dub = second sound (S2) closure of semilunar valves (aortic and pulmonary)

no sounds associated with valves opening

systole between lub and dub

diastole between dub and next lub

Question 28

what happens to the heart sounds during inspiration?

Answer 28

the lungs create a vacuum so instead of just lub dub, you have the S2 valve splitting the valve between what’s coming from the aortic and pulmonary valves

during expiration, it’s the normal lub dub!

Question 29

what is the skeleton of the heart?

Answer 29

a fibrous connective tissue to which valves and muscles of the heart are attached

it provides support and rigidity and serves as an electrical insulator preventing conduction between atria and ventricles

Question 30

what’s the difference in pressure between the right and left ventricle?

Answer 30

the BP in the left ventricle is SO much bigger than the right ventricle

Question 31

what are the important structures in the right atrium?

Answer 31

1. crista terminalis
2. musculi pectinati
3. fossa ovalis (previously the foramen ovale)