The Heart

Question 1

What does ECG stand for?

Answer 1

Electrocardiogram (measures the electrical impulses of the heart)

Question 2

what are the 3 parts of a normal ECG?

Answer 2

P wave (atria contracting)
QRS complex (Ventricles contracting)
T wave (Electrical activity dissipates)

Question 3

what is Tachycardia?

Answer 3

heart rate that is too quick

Question 4

what is Bradycardia?

Answer 4

Heart rate that is too slow

Question 5

What is Fibrillation?

Answer 5

Heart rate that is fluttering

Question 6

What is an ectopic heart beat? (arrhythmia)

Answer 6

An irregular heartbeat

Question 7

Name the 4 chambers of the heart

Answer 7

Right/left atrium

Right/left ventricle

Question 8

Name the valves in between the atria and the ventricles

Answer 8

atrioventricular valves

Question 9

name the valves in between the ventricles and the arteries

Answer 9

Semi-lunar

Question 10

what is the vein on the right side of the heart?

Answer 10

Superior/inferior vena cava

Question 11

what is the artery on the right side of the heart?

Answer 11

Pulmonary artery

Question 12

What is the vein on the left side of the heart?

Answer 12

Pulmonary vein

Question 13

What is the artery on the left side of the heart?

Answer 13

Aorta

Question 14

where is the septum of the heart?

Answer 14

the centre

Question 15

where is the apex of the heart?

Answer 15

the bottom

Question 16

what do heart string do?

Answer 16

prevent the valves flipping

Question 17

what do coronary arteries do?

Answer 17

carry blood to the heart muscle

Question 18

What do you call the heart muscle?

Answer 18

myocardium

Question 19

what are the 12 steps of the cardiac cycle?

Answer 19

• An electrical impulse is generated by the SA node
• A wave of electrical activity spreads across the atria
• This causes the atria to contract
• Blood is forces through the AV valves to ventricles
• Insulating fibres at the bottom of the atria (atrioventricular septum) prevent the electrical activity from spreading
• the impulse reaches the AV node
• This is important as there is a delay after the atria have contracted to allow the ventricles to fill with blood
• The Bundle Of His transmits the impulse down the septum of the heart
• The Purkyne fibres spread the electrical activity up the ventricles
• This ensures the ventricels contract from the bottom forcing the blood up through the aorta/pulmonary artery
• The atria are already relaxed/refilling with blood
• The SA node generates a second impulse and the process starts again

Question 20

Where is the SA node found?

Answer 20

In the right atrium.

Question 21

Where is the AV node found?

Answer 21

In the centre of the heart

Question 22

Where is the Bundle of His found?

Answer 22

Runs down the septum of the heart

Question 23

Where are the Purkyne Fibres found?

Answer 23

Run up the walls of the ventricles

Question 24

why is the heart described as myogenic?

Answer 24

the heart muscle generates it’s own electrical impulse

Question 25

what is the SA node best described as?

Answer 25

The pacemaker of the heart, it coordinates the contractions so the muscle cells contract at the correct time.

Question 26

What do the insulation fibres do and why is this important?

Answer 26

• They are at the bottom of the atria and prevent the electrical impulse from spreading to the ventricles.
• There is a pause at the AV node to allow the ventricles to fill up.

Question 27

Why are both atrioventricular valves attached to the ventricle wall by tendons?

Answer 27

When pressure on the valve is high, the valve gate is forced shut and the tendons are pulled tight. The tendons prevent the valves from being pushed inside out, which would allow blood to flow back into the atria and disrupt the heartbeat.