Topic 6.2: The Blood System Flashcards Preview

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Flashcards in Topic 6.2: The Blood System Deck (31):
1

What are the four chambers of the human heart?

two atria and two ventricles

2

What is the purpose of the atria?

The atria act as reserviors, by which blood returning to the heart is collected via veins (and passed on to ventricles)

3

What is the purpose of the ventricles?

The ventricles act as pumps, expelling the blood from the heart at high pressure via arteries

4

What does the left side of the heart pump?

The left side of the heart pumps oxygenated blood around the body (systemic circulation)

5

What does the right side of the heart pump?

The right side of the heart pumps deoxygenated blood to the lungs (pulmonary circulation)

6

What is the function of arteries?

Arteries convey blood at high pressure from the ventricles to the tissues of the body

7

What is the structure of arteries?

Arteries have muscle cells and elastic fibres in their walls

8

How do muscle fibers help in blood flow?

The muscle fibres help to form a rigid arterial wall that is capable of withstanding the high blood pressure without rupturing

9

How do elastic fibers help in blood flow?

The elastic fibres allow the arterial wall to stretch and expand upon the flow of a pulse through the lumen

10

What is the structure and function of capillaries?

Capillaries have permeable walls that allow exchange of material between cells in tissues and blood in capillaries

11

What is the function of veins?

The function of veins is to collect the blood from the tissues and convey it at low pressure to the atria of the heart

12

What is the purpose of valves in veins?

Valves in veins and the heart ensure circulation of blood by preventing backflow

13

Describe the walls of arteries

Arteries have thick walls and narrow lumens because they transport blood at high pressure

14

Describe the walls of capillaries

Capillaries have walls that are only a single cell thick because they exchange materials between blood and tissue

15

Describe the walls of veins

Veins have thin walls with wide lumens and valves because they transport blood at low pressure

16

Describe the two atria in terms of heart structure

Two atria (singular = atrium) – smaller chambers near top of heart that collect blood from body and lungs

17

Describe the two ventricles in terms of heart structure

Two ventricles – larger chambers near bottom of heart that pump blood to body and lungs

18

Describe the atrioventricular valves in terms of heart structure

Atrioventricular valves (between atria and ventricles) – bicuspid valve on left side ; tricuspid valve on right side

19

Describe the semilunar valves in terms of heart structure

Semilunar valves (between ventricles and arteries) – aortic valve on left side ; pulmonary valve on right side

20

Describe the vena cava in terms of heart structure

Vena cava (inferior and superior) feeds into the right atrium and returns deoxygenated blood from the body

21

Describe the pulmonary artery in terms of heart structure

Pulmonary artery connects to the right ventricle and sends deoxygenated blood to the lungs

22

Describe the pulmonary vein in terms of heart structure

Pulmonary vein feeds into the left atrium and returns oxygenated blood from the lungs

23

Describe the aorta in terms of heart structure

Aorta extends from the left ventricle and sends oxygenated blood around the body

24

Define myogenic in terms of heart contraction

The contraction of the heart is myogenic – meaning that the signal for cardiac compression arises within the heart tissue itself

25

Define sinoatrial node

Within the wall of the right atrium are a specialised cluster of cardiomyocytes which direct the contraction of heart muscle tissue

This cluster of cells are collectively called the sinoatrial node (SA node or SAN)

26

What is the first step of the electrical conduction of a heart beat?

The sinoatrial node sends out an electrical impulse that stimulates contraction of the myocardium (heart muscle tissue)

27

After The sinoatrial node sends out an electrical impulse that stimulates contraction of the myocardium (heart muscle tissue) what is the next step of the electrical conduction of a heart beat?

This impulse directly causes the atria to contract and stimulates another node at the junction between the atrium and ventricle

28

After This impulse directly causes the atria to contract and stimulates another node at the junction between the atrium and ventricle what is the next step of the electrical conduction of a heart beat?

This second node – the atrioventricular node (AV node) – sends signals down the septum via a nerve bundle (Bundle of His)

29

After This second node – the atrioventricular node (AV node) – sends signals down the septum via a nerve bundle (Bundle of His) what is the lastt step of the electrical conduction of a heart beat?

The Bundle of His innervates nerve fibres (Purkinje fibres) in the ventricular wall, causing ventricular contraction

30

Define coronary arteries

Coronary arteries are the blood vessels that surround the heart and nourish the cardiac tissue to keep the heart working

31

Define atherosclerosis

Atherosclerosis is the hardening and narrowing of the arteries due to the deposition of cholesterol

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