3.2 The Heart & Cardiac Cycle Flashcards Preview

A Level Biology > 3.2 The Heart & Cardiac Cycle > Flashcards

Flashcards in 3.2 The Heart & Cardiac Cycle Deck (44):
1

(Heart) What is myocardium and what does it do?

Heart muscle
Beats continually without tiring

2

(Heart) what is the pericardium and what does it do?

Double layered sac covering the heart
Protects it from over expansion and infection

3

(Heart) the pericardial fluid is secreted to do what?

Protect the heart from jerking movements and shock

4

(Heart) the aorta leaves which ventricle? And what does it do?

The left
Distributes oxygenated blood to the body

5

(Heart) the pulmonary arteries leave which ventricle? And what do they do?

Right ventricle
Carry deoxygenated blood from heart to lungs

6

(Heart) the vena cava enters where and does what?

Right atrium
Delivers deoxygenated blood from body

7

(Heart) what do the coronary arteries do?

Deliver oxygen to the heart muscles

8

(Heart) blockage of the coronary arteries can result in what?

Heart attack

9

(Heart) what do valves do?

Keep blood flowing in one direction

10

(Heart) what are the two atrioventricular valves called?

Bicuspid
Tricuspid

11

(Heart) the bicuspid and tricuspid AV valves prevent what happening?

Backflow of blood from ventricles into atrium

12

(Heart) the semilunar valves allow what to happen?

Blood to be pumped out into arteries
But prevent it flowing back in

13

(Cardiac cycle) in diastole what are the heart muscles?

Relaxed

14

(Cardiac cycle) diastole - deoxygenated blood enters the right atrium from where?

The vena cava

15

(Cardiac cycle) diastole - oxygenated blood enters the left atrium from where?

The pulmonary vein

16

(Cardiac cycle) as atria fill with blood what increases?

Pressure

17

(Cardiac cycle) increase in pressure forces what open?

AV valves so blood flows into ventricles

18

(Cardiac cycle) in atrial systole what do the walls of the atria do?

Contract

19

(Cardiac cycle) atrial systole pushes what?

Remaining blood into ventricles

20

(Cardiac cycle) in ventricular systole what do the ventricles do?

Contract

21

(Cardiac cycle) when the ventricles contract what increases?

Pressure in the ventricles

22

(Cardiac cycle) increased pressure in the ventricles forces what two things to happen?

AV valves to shut
semilunar valves to open

23

(Cardiac cycle) when the semilunar valves open blood is forced where?

Out of heart to lungs and body

24

(Heartbeat) what is the SAN and where is it found?

Sino atrial node
Found in wall of right atrium

25

(Heartbeat) the SAN does what?

Sets heartbeat by sending out waves of electrical activity to atria walls

26

(Heartbeat) the waves the SAN sends causes the right and left atria to do what?

Contract at the same time

27

(Heartbeat) what prevents the waves being passed directly from atria to ventricles?

Non conducting collagen tissue

28

(Heartbeat) the waves are transferred from the SAN to where?

The AVN

29

(Heartbeat) what is the AVN?

Atrioventricular nods

30

(Heartbeat) the AVN passes the waves of electrical activity to where?

The bundle of his

31

(Heartbeat) why is there a slight delay before the AVN reacts?

To ensure ventricles have emptied before atria contract

32

(Heartbeat) what is the bundle of his?

Group of muscle fibres conducting waves of electrical impulses to finer muscle in the ventricle walls

33

(Heartbeat) what are the finer muscle fibres in the ventricle walls called?

Purkyne tissue

34

(Heartbeat) what does the Purkyne tissue do?

Carries impulse to walls of ventricles causing them to contract simultaneously from the bottom up

35

(ECGs) what does an electrocardiograph do and what is it used for?

Electrical activity of the heart
Used to check heart function

36

(ECGs) what is the P wave caused by?

Contraction and depolarisation of atria

37

(ECGs) what is the QRS complex?

Contraction and depolarisation of ventricles

38

(ECGs) the T wave is caused by what?

Relaxation and repolarisation of ventricles

39

(ECGs) the bigger the wave the more what?

Electrical charge

40

(ECGs) what is the term for a heart beat that is too fast?

Tachycardia

41

(ECGs) when is a heart beat too fast?

Around 120bpm

42

(ECGs) what is it called when heartbeat is too slow? And when is this?

Bradycardia
60bpm

43

(ECGs) what is an ectopic heartbeat?

Extra heart beat caused by early contraction of atria or ventricles

44

(ECGs) what is fibrillation?

Irregular heart beat
Atria or ventricles stop contracting properly

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