Gross And Cellular Structure Of The Heart Flashcards Preview

Cardio-respiratory Physiology And Pharmacology > Gross And Cellular Structure Of The Heart > Flashcards

Flashcards in Gross And Cellular Structure Of The Heart Deck (36)
0

What are the roles of cardiac muscle ?

1- supply oxygenated blood containing nutrients to major organs
2- remove waste products formed during metabolism

1

What is the positioning of the heart in the body ?

Behind the sternum for protection
Extends from 2nd to 5th rib
Angled in the chest cavity

2

Describe the pulmonary circulation ?

Pulmonary artery which carries deoxygenated blood to the lungs
Pulmonary veins which carries oxygenated blood to the heart
Important for taking blood to the lungs for re-oxygenation

3

Describe the coronary circulation ?

Is provides oxygenated blood to the heart
Coronary arteries branch from the base of the aorta
Left coronary artery splits into the the anterior inter ventricular artery and supplies mainly the wall of left ventricle
Right splits into marginal artery and supplies the free right ventricular wall and goes around to the posterior aspect of the heart
The venous blood drains into the coronary sinus

4

What mirrors the marginal artery in the coronary vessels ?

Small cardiac vein

5

What vessel mirrors then terror interventricular artery ?

Great cardiac vein

6

Describe the systemic circulation ?

Provides oxygenated blood to the organs and tissues of the body
Served by the left side of the heart

7

What arteries of the systemic circulation supply the head and brain ?

Vertebral and carotid arteries

8

What the 1st vessel to branch from the aorta ?

brachiocephalic trunk

9

What arteries of the systemic circulation supply blood to the arms ?

Subclavian arteries, they run under the clavicles

10

What artery supplies blood to the upper part of the digestive tract ?

Superior mesenteric

11

Which artery supplies the lower part of the digestive tract?

Inferior mesenteric

12

What arteries supply blood to the pelvis and legs ?

The common iliac and internal iliac feed into the external iliac and deep femoral

13

What is the outer layer of the heart called ?

Fibrous pericardium
-protects the heart
-anchors the heart to adjacent structures
-it's indistensible so it prevents overfilling

14

What is the inner layer of the heart called ?

Serous pericardium
- secretes fluid into the pericardial cavity to aid the twisting of the heart during pumping

15

What is the epicardium?

It surrounds the outside of the muscular surface of the heart

16

What is the endocardium ?

It surrounds the inner face of the heart

17

What is pericarditis ?

It is the inflammation of the pericardial membranes
- causes sharp chest pains
- with a stethoscope you can hear the membrane rubbing against one another

18

What is the right AV valves called ?

Tricuspid valve cos it has 3 cusps

19

What is the right AV valve called ?

It's the biscuspid valve or mitral valve with 2 cusps

20

How many cusps do the semi-lunar valves have ?

3

21

Why do valves open and close ?

It is a passive movement based upon the pressure gradients across them

22

When do valves open ?

They open when the pressure gradient is greater behind the valves

23

When are valves shut ?

They are shut when the pressure gradient is greater in front of the valves

24

What is the role of the papillary muscles ?

They are used to close the AV valves
When the ventricles contract the pressure is greater in the ventricles than in the atria so the valves shut. This occurs because the papillary muscles also contract when the ventricles contract and they pull on chordae tendinae to prevent the valves eventing into the atria

25

What are the dimensions of muscles cells of the ventricles ?

120 micrometers long
30 micrometers wide

26

How do cardiac muscle cells join together ?

They are joined together by intercalated discs which tend to join end to end

27

What are the 2 roles of the intercalated discs ?

1- they act by firmly binding together the adjacent cells allowing mechanically coupling
2- this also enables electrical coupling

28

What are gap junctions ?

They are proteins made up of connexins which create ion channels so small ions can pass between cells
Allow electrical coupling so aps can pass between cells easily and quickly
Enables heart to function as functional syncytium

29

What is the flow of arteries for the upper chest and arms ?

Subclavian - axialllary - brachial arteries

30

Where does venous blood from the coronary circulation drain into ?

Coronary sinus then into right atrium.

31

What is the double walled sac of the heart called ?

Pericardium

32

When do valves open ?

When pressure behind them is greater

33

When do valves close ?

When pressure is greater in front of them

34

What size of the gap between adjacent cardiac cells ?

0.02 micrometers - filled with connective tissue

35

What causes the membranes of adjacent cardiac cells to be joined together more strongly at certain points ?

Desmosomes