Histology Of The Heart - Gerdes

Question 1

Myocyte proliferation ceases shortly after __________

Answer 1

Birth

Question 2

What are the 3 layers of the heart?

Answer 2

Endocardium
Myocardium
Epicardium

Question 3

Endocardium

Answer 3

Endothelium
Loose to dense connective tissue
Purkinje fibers (deep)

Question 4

Myocardium

Answer 4

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

Question 5

Epicardium

Answer 5

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

Question 6

Which layer is most prominent in the atria?

Answer 6

Endocardium

Question 7

Which later is fat found?

Answer 7

Epicardium

Question 8

Skeletal muscle

Answer 8

Strong, quick, discontinuous, voluntary contraction

Question 9

Cardiac muscle

Answer 9

Strong, quick, continuous, involuntary contraction

Question 10

Smooth muscle

Answer 10

Weak, slow, involuntary contraction

Question 11

Intercalated discs (in myocytes)

Answer 11

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

Question 12

Cardiac muscle

Answer 12

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

Question 13

Cardiac hypertrophy

Answer 13

Increase myocyte diameter leads to wall thickening.

Increase myocyte lengthening from series sarcomere addition -> chamber dilation

Question 14

Papillary Muscles

Answer 14

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

Question 15

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

Answer 15

Mesothelial cells

Question 16

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

Answer 16

Epicardium

Question 17

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

Answer 17

Adipose tissue

Question 18

AV valves are also called ______

Answer 18

Mitral (left)

Tricuspid (right)

Question 19

Aortic and pulmonary values are also called

Answer 19

Semilunar

Question 20

Area between valves is called ________

Answer 20

Trigone

Question 21

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

Answer 21

Interventricular septum

Question 22

What lines valves?

Answer 22

Simple squamous epithelium on both sides with dense connective tissue core

Question 23

Chordae tendinar

Answer 23

Dense connective tissue core covered by endothelium

Question 24

Cardiac conduction system

Answer 24

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

Question 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

Answer 25

Intermodal tracts

Question 26

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

Answer 26

Bundle of His

Question 27

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

Answer 27

Purkinje fibers

Question 28

Modified cardiac muscle cells specialized to conduct impulses

Answer 28

Nodal cells, AV bundle, bundle branches, purkinje fibers

Question 29

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

Answer 29

Smaller

Question 30

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

Answer 30

Larger

Question 31

Conduction cells have….

Answer 31

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