Histology Of The Heart - Gerdes Flashcards Preview

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Flashcards in Histology Of The Heart - Gerdes Deck (31):
1

Myocyte proliferation ceases shortly after __________

Birth

2

What are the 3 layers of the heart?

Endocardium
Myocardium
Epicardium

3

Endocardium

Endothelium
Loose to dense connective tissue
Purkinje fibers (deep)

4

Myocardium

Cardiac muscle (myocytes)
In loose connective tissue
Arterioles, capillaries, lymphatics

5

Epicardium

Fibroelastic connective tissue
Coronary arteries with vasa vasorum, coronary veins
Fat
Mesothelium

6

Which layer is most prominent in the atria?

Endocardium

7

Which later is fat found?

Epicardium

8

Skeletal muscle

Strong, quick, discontinuous, voluntary contraction

9

Cardiac muscle

Strong, quick, continuous, involuntary contraction

10

Smooth muscle

Weak, slow, involuntary contraction

11

Intercalated discs (in myocytes)

Join cells, help synchronize myocyte contraction by allowing electrical coupling with relatively unrestricted ionic passage across the membranes of adjoining cells

12

Cardiac muscle

Is specialized striated muscle. Has more mitochondria (25-35% of cell) than skeletal muscle (3-5%) and is very dependent on aerobic metabolism

13

Cardiac hypertrophy

Increase myocyte diameter leads to wall thickening.

Increase myocyte lengthening from series sarcomere addition -> chamber dilation

14

Papillary Muscles

Finger like projections from the inner surface of the heart connecting to chordae tendinae

Parallel myocytes and capillaries from the core

Covered by endocardium on the surface

Has been used by animal physiologists to study cardiac muscle function in vitro

15

Epicardium has a layer of __________ cells on the outer surface of the heart with underlying connective tissue

Mesothelial cells

16

Blood vessels and nerves which supply the heart are present in the ____________

Epicardium

17

The epicardium is largely composed of ______________ which acts as cushion to the pericardial cavity

Adipose tissue

18

AV valves are also called ______

Mitral (left)
Tricuspid (right)

19

Aortic and pulmonary values are also called

Semilunar

20

Area between valves is called ________

Trigone

21

You find dense, fibrous connective tissue surrounding the 4 major valves, in the trigone, and in the __________

Interventricular septum

22

What lines valves?

Simple squamous epithelium on both sides with dense connective tissue core

23

Chordae tendinar

Dense connective tissue core covered by endothelium

24

Cardiac conduction system

Electrical impulses generated at the SA node, group of specialized cardiac muscle cells present near the junction of superior vena cava and right atrium

"Pacemaker" of the heart 60-100 bpm

25

The impulse which the SA node initiates spreads along the cardiac muscle fibers of the atria and along _____________ made of modified cardiac muscle fibers

Intermodal tracts

26

Once picked up at the AV node, it is conducted across the fibrous skeleton to the ventricles by the _____________

Bundle of His

27

The bundle of HIS divides into right and left bundle branches and then into subendothelial branches called _____________

Purkinje fibers

28

Modified cardiac muscle cells specialized to conduct impulses

Nodal cells, AV bundle, bundle branches, purkinje fibers

29

The cells in the SA and AV nodes are ________ than normal working myocytes

Smaller

30

Purkinje fivers, AV bundle and the bundle branches are ___________ than normal myocytes

Larger

31

Conduction cells have....

Fever my off rails, few to no T tubules, and are rich in glycogen

The parts of the cardiac conduction system convey the impulse about 4x faster than regular cardiac muscle fibers