Physiology and Health: The Structure and Function of the Heart

Question 1

The heart has four chambers and works as a double pump, what are the four chambers?

Answer 1

Right atrium, right ventricle, left atrium and left ventricle

Question 2

What does the right side of the heart do?

Answer 2

Collects deoxygenated blood from the body and pumps it to the lungs to collect oxygen

Question 3

What does the left side of the heart do?

Answer 3

Collects oxygenated blood from the lungs and pumps it to the body

Question 4

The volume of blood pumped through each ventricle per minute is called the cardiac output, what is the equation for cardiac output?

Answer 4

Cardiac output = Heart rate x Stroke volume: CO = HR x SV

Question 5

What do the left and right ventricles do?

Answer 5

Pump the same volume of blood through the aorta and pulmonary artery

Question 6

What is the cardiac cycle?

Answer 6

The pattern of contraction (systole) and relaxation (diastole) of the heart muscle in one complete heartbeat

Question 7

What happens during diastole?

Answer 7

Blood returning to the atria flows into the ventricles

Question 8

Atrial systole does what?

Answer 8

Transfers the remainder of the blood through the atrio-ventricular (AV) valves to the ventricles

Question 9

What happens during ventricular systole?

Answer 9

It closes the AV valves and pumps the blood out through the semi-lunar valves to the aorta and pulmonary artery

Question 10

What happens in diastole?

Answer 10

The higher pressure in the arteries closes the SL valves

Question 11

Deoxygenated blood returning from the body via the vena cava does what?

Answer 11

Fills the right atrium (during atrial systole)

Question 12

The build-up of pressure during atrial diastole does what?

Answer 12

Forces open the AV valve and blood flows into the right ventricle during ventricular diastole

Question 13

The right atrium contracts, doing what?

Answer 13

Forcing all the blood into the right ventricle (atrial systole)

Question 14

Once full, the right ventricle’s muscular walls contract (ventricular systole), doing what?

Answer 14

Closing the AV valve and forcing the blood up through the semi-lunar valve and out through the pulmonary artery to the lungs

Question 15

Oxygenated blood returning from the lungs via the pulmonary vein does what?

Answer 15

Fills the left atrium (during atrial diastole)

Question 16

The build-up of pressure during atrial diastole does what?

Answer 16

Forces open the AV valve and blood flows into the left ventricle. The atrium contracts forcing all the blood into the ventricle (atrial systole)

Question 17

Once full, the left ventricle’s muscular walls contract (ventricular systole), doing what?

Answer 17

Closing the AV valve and forcing the blood up through the SL valve and out through the aorta to the body’s organs

Question 18

The opening and closing of the AV and SL valves are responsible for what?

Answer 18

The heart sounds heard with a stethoscope

Question 19

Where does the heartbeat originate?

Answer 19

In the heart itself

Question 20

The auto-rhythmic cells of the sino-atrial node (SAN) or pacemaker, located in the wall of the right atrium, does what?

Answer 20

Set the rate at which the heart contracts

Question 21

The timing of cardiac muscle cell contraction is controlled by what?

Answer 21

Impulses from the SAN spreading through the atria causing atrial systole

Question 22

The impulses then travel to the atrio-ventricular node (AVN), located in the centre of the heart and then what happens?

Answer 22

Impulses from the AVN travel down fibres in the centre wall of the heart and then up through the walls of the ventricles, causing ventricular systole

Question 23

Impulses in the heart generate currents that can be detected by what?

Answer 23

An electrocardiogram (ECG)

Question 24

What does the medulla in the brain do?

Answer 24

Regulates the rate of the SAN through the antagonistic action of the autonomic nervous system (ANS)

Question 25

A sympathetic (accelerator) nerve releases noradrenaline which does what?

Answer 25

Decreases the heart rate

Question 26

When does blood pressure increase and decrease?

Answer 26

Increases during ventricular systole.

Decreases during diastole.

Question 27

Measurement of blood pressure is performed using what?

Answer 27

A sphygmomanometer

Question 28

What does an inflatable cuff do?

Answer 28

Stops blood flow in the artery and deflates gradually

Question 29

The blood starts to flow (detected by a pulse) when?

Answer 29

At systolic pressure

Question 30

The blood flows freely through the artery (and a pulse is not detected) when?

Answer 30

At diastolic pressure

Question 31

What is the typical blood pressure reading for a young adult?

Answer 31

120/80 mmHg

Question 32

Hypertension (high blood pressure) is a major risk factor for many diseases and conditions, what is an example of one of these?

Answer 32

Coronary heart disease (CHD)