Structure and Function of the Heart

Question 1

Name the blood vessels which supply
the heart itself with blood

Answer 1

Coronary arteries

Question 2

Define the term cardiac output

Answer 2

A measure of the volume of blood
pumped through each ventricle per
minute

Question 3

Give the equation for measuring
cardiac output

Answer 3

CO = HR x SV

Question 4

How does the volume of blood
pumped from the left ventricle to
the aorta and right ventricle to the
pulmonary artery compare?

Answer 4

The volumes are the same

Question 5

State the three phases of the
cardiac cycle

Answer 5

Diastole
Atrial systole
Ventricular systole

Question 6

Describe diastole and describe the
condition of the valves during this

Answer 6

The relaxation of the heart, where blood returning to the atria flows into the ventricles.

Semi-lunar (SL) valves closed

Question 7

Describe atrial systole and
describe the condition of the
valves during this

Answer 7

Contraction of the atria
blood transferred from atria to ventricles.

AV valves open. SL closed.

Question 8

Describe ventricular systole and
describe the condition of the valves
during this

Answer 8

Contraction of the ventricles
blood transferred from ventricles aorta and pulmonary artery.

AV valves closed.

SL open.

Question 9

What causes the heart sounds
heard with a stethoscope

Answer 9

The closing of the valves

Question 10

Where is the Sino-artial node

Answer 10

upper right side of right atrium

Question 11

Where is the atrioventricular node?

Answer 11

centre of the heart

Question 12

What sets the rate at which the
heart contracts?

Answer 12

Auto-rhythmic cells of the sino-atrial
node (SAN) or pacemaker

Question 13

Describe the pathway of the impulses
from the SAN and describe what
occurs because of this

Answer 13

Spread across the atria causing atrial
systole.

Also pass to AVN.

Question 14

Describe the pathway of the
impulses from the AVN and describe
what occurs because of this

Answer 14

Down the fibres in the central wall
of the heart and then up through
the walls of the ventricles,

causing ventricular systole

Question 15

What is detected by an
electrocardiogram (ECG)?

Answer 15

Currents generated by electrical
impulses in the heart

Question 16

State how the rate of the
sino-atrial node (SAN) is regulated

Answer 16

The medulla regulates it
through the antagonistic
action of the autonomic nervous
system (ANS)

Question 17

Name two nerves that make up the
ANS

Answer 17

Sympathetic and parasynmpathetic

Question 18

Describe the role of the
sympathetic nerve

Answer 18

Increases the heart rate by
releasing noradrenaline

Question 19

Describe the role of the
parasympathetic nerve

Answer 19

Decreases the heart rate by
releasing acetylcholine

Question 20

Describe blood pressure changes
during ventricular systole and
diastole

Answer 20

Increases during ventricular systole
and decreases during diastole

Question 21

Name the instrument used to
measure blood pressure

Answer 21

Sphygmomanometer

Question 22

Describe the use of a
sphygmomanometer

Answer 22

An inflatable cuff stops blood flow in an
artery and deflates gradually.

The blood starts to flow (detected by a pulse) at systolic pressure and then flows freely through the artery (no pulse detected) at diastolic pressure.

Question 23

State a typical blood pressure for a
young adult

Answer 23

120/80mmHg

Question 24

Why is it important to check blood
pressure?

Answer 24

Hypertension (high blood pressure)
is a major risk factor for many
diseases, including coronary heart
disease

Question 25

How to calculate Heart Rate

Answer 25

60 / length of 1 heartbeat (seconds)
(systoly+ diastole)