3.2 The Heart & Cardiac Cycle

Question 1

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

Answer 1

Heart muscle

Beats continually without tiring

Question 2

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

Answer 2

Double layered sac covering the heart

Protects it from over expansion and infection

Question 3

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

Answer 3

Protect the heart from jerking movements and shock

Question 4

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

Answer 4

The left

Distributes oxygenated blood to the body

Question 5

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

Answer 5

Right ventricle

Carry deoxygenated blood from heart to lungs

Question 6

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

Answer 6

Right atrium

Delivers deoxygenated blood from body

Question 7

(Heart) what do the coronary arteries do?

Answer 7

Deliver oxygen to the heart muscles

Question 8

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

Answer 8

Heart attack

Question 9

(Heart) what do valves do?

Answer 9

Keep blood flowing in one direction

Question 10

(Heart) what are the two atrioventricular valves called?

Answer 10

Bicuspid

Tricuspid

Question 11

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

Answer 11

Backflow of blood from ventricles into atrium

Question 12

(Heart) the semilunar valves allow what to happen?

Answer 12

Blood to be pumped out into arteries

But prevent it flowing back in

Question 13

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

Answer 13

Relaxed

Question 14

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

Answer 14

The vena cava

Question 15

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

Answer 15

The pulmonary vein

Question 16

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

Answer 16

Pressure

Question 17

(Cardiac cycle) increase in pressure forces what open?

Answer 17

AV valves so blood flows into ventricles

Question 18

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

Answer 18

Contract

Question 19

(Cardiac cycle) atrial systole pushes what?

Answer 19

Remaining blood into ventricles

Question 20

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

Answer 20

Contract

Question 21

(Cardiac cycle) when the ventricles contract what increases?

Answer 21

Pressure in the ventricles

Question 22

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

Answer 22

AV valves to shut

semilunar valves to open

Question 23

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

Answer 23

Out of heart to lungs and body

Question 24

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

Answer 24

Sino atrial node

Found in wall of right atrium

Question 25

(Heartbeat) the SAN does what?

Answer 25

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

Question 26

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

Answer 26

Contract at the same time

Question 27

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

Answer 27

Non conducting collagen tissue

Question 28

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

Answer 28

The AVN

Question 29

(Heartbeat) what is the AVN?

Answer 29

Atrioventricular nods

Question 30

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

Answer 30

The bundle of his

Question 31

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

Answer 31

To ensure ventricles have emptied before atria contract

Question 32

(Heartbeat) what is the bundle of his?

Answer 32

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

Question 33

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

Answer 33

Purkyne tissue

Question 34

(Heartbeat) what does the Purkyne tissue do?

Answer 34

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

Question 35

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

Answer 35

Electrical activity of the heart | Used to check heart function

Question 36

(ECGs) what is the P wave caused by?

Answer 36

Contraction and depolarisation of atria

Question 37

(ECGs) what is the QRS complex?

Answer 37

Contraction and depolarisation of ventricles

Question 38

(ECGs) the T wave is caused by what?

Answer 38

Relaxation and repolarisation of ventricles

Question 39

(ECGs) the bigger the wave the more what?

Answer 39

Electrical charge

Question 40

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

Answer 40

Tachycardia

Question 41

(ECGs) when is a heart beat too fast?

Answer 41

Around 120bpm

Question 42

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

Answer 42

Bradycardia | 60bpm

Question 43

(ECGs) what is an ectopic heartbeat?

Answer 43

Extra heart beat caused by early contraction of atria or ventricles

Question 44

(ECGs) what is fibrillation?

Answer 44

Irregular heart beat | Atria or ventricles stop contracting properly