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Flashcards in Heart Histology Deck (20):
1

What are the characteristics of cardiac muscle cells in cross sections?

1. Oval nucleus
2. 1 centrally located nucleus
3. Cross striations

2

What are the 3 layers of the heart?

Endocardium
myocardium
Epicardium

3

What is also known as the epicardium?

Viceral pericardium

4

What is the endocardium?

Inner lining of the heart and valves
- continuous with tunica intima of blood vessels

5

What are the 3 components of the endocardium?

Inner- Simple squamous endothelium and sunendothelial CT

Middle- CT and Smooth muscle

Outer- Subendocardial CT

6

Which layer and component is the conduction system located?

Endocardium
Outer component (Subendocardial CT)

7

On histological view the endocardium and myocardium look like/

Smooth
Large oval nuclei that are centrally located

8

What is the endomysium?

CT that ensheaths each fiber

9

What is characteristic of the myocardium?

Arranged in complex spirals that contains vessels and of blood and lymphatics

10

What are the function of Endocrine secretions of the heart and where do they arise?

ANF- Atrial natriuretic factor
BNF- Brain Natriuretic factor
- both control urinary excretion of NA to regulate BP

11

Can you see intercalated discs on longitudinal sections?

no

12

What make up the intercalated discs?

1. Desmosomes (fascia maculae)
2. Gap junctions
3. Fascia adherens

13

What is characteristic of the epicardium compared to other layers of the heart?

Adipose tissue
- able to distinguish between this and endocardium
- may also see nerve fibers arts, veins and loose CT

14

What makes up the outer mesothelial layer?

Simple squamous epithelium
Outer most layer of the epicardium

15

What is cardiac tampenade and what is its cause?

Excess fluid in the pericardial cavity
- pericarditis or myocardial rupture
- compresses heart and prevents blood from filling

16

Where is the location of the SA node?

Located at the junction of the superior vena cava of right atrium
- has own arterial and ANS supply

17

Where is the location of the AV node?

near opening of Coronary sinus
- Also have its own arterial and ANS supply

18

What supplies the papillary muscles of the heart?

Purkinje fibers

19

What cause the increased size and lack of staining of purkinje fibers?

Glycogen stores

20

What are some purposes of the cardiac skeleton?

1. Support
2. Insulator the prevents the flow of the electrical impulses between the atria and ventricles