Cardiac Cycle

Question 1

What is the correct sequence of flow of an electrical impulse through the heart?

Answer 1

SA node, AV node, AV bundle, Purkinje fibers

Question 2

The T wave on an ECG is due to?

Answer 2

Ventricular repolarization

Question 3

The left ventricle refills with blood in preparation for initiation of the next cardiac cycle during ventricular?

Answer 3

Diastole

Question 4

What is special about the atrioventricular (AV) bundle (bundle of His)

Answer 4

Is the only site where action potentials can conduct from the atria to the ventricles

Question 5

Ventricular systole is caused by?

Answer 5

Ventricular depolarization

Question 6

What does SA stand for?

Answer 6

Sino atrial node (SA) NODE

Question 7

What does AV stand for?

Answer 7

Atrioventricular node (AV) NODE

Question 8

State what happens to the atria when the impulses spread through them

Answer 8

Atria depolarise and contract (Systole)

Question 9

State what happens to the ventricles when the impulses spread through them:

Answer 9

Ventricles depolarise and contract (Systole)

Question 10

When the atrio-ventricular valves shut the ventricles are in what?

Answer 10

Systole

Question 11

When the semilunar valves shut the ventricles are in what?

Answer 11

Diastole

Question 12

Describe the electrical events which produce the P wave.

Answer 12

Atria Depolarisation

Question 13

Name the mechanical cardiac event which accompanies the P wave.

Answer 13

Atrial systole

Question 14

Describe the electrical events which produce the QRS complex

Answer 14

Depolarization of the ventricles

Question 15

Name the mechanical cardiac event which accompanies the QRS complex.

Answer 15

Ventricular systole

Question 16

Describe the electrical events which produce the T wave.

Answer 16

Repolarisation of the ventricles

Question 17

Name the mechanical cardiac event which accompanies the T wave

Answer 17

Ventricular Diastole

Question 18

What is the importance of the Sinoatrial (SA) node

Answer 18

The cells of the SA node spontaneously & rhythmically initiate their own depolarisation
It is the hearts pacemaker and determines heart rate.

Question 19

Explain Ventricular depolarisation

Answer 19

Stimulates the ventricles to contract from the apex

upwards and then the ventricles relax

Question 20

List some Age related changes to the cardiac cycle

Answer 20

- Blood vessel wall lining (endothelium)
becomes thickened
- Heart valves (specifically the Aortic valve)
become stiffened and thicker. 
- Progressive degeneration of cardiac
structures,

Question 21

What will affect the cardiac cycle?

Answer 21

• Conduction / Electrical conditions
• Mechanical/ Pump Failure conditions
• Valve problems=blood flow issue (valve stenosis) or an incompetent
  valve= increasing cardiac pressure leading to pump failure issues.

Question 22

Describe two Lethal heart rhythms

Answer 22

• Ventricular tachycardia

- Ventricular fibrillation

Question 23

What is the role of the cardiac cycle in the medulla oblongata?

Answer 23

To increase or decrease firing of SA node/rate and contractility

Question 24

The left ventricle refills with blood in preparation for initiation of the next cardiac cycle during ventricular

Answer 24

Diastole

Question 25

Ventricular systole is caused by?

Answer 25

Ventricular depolarization

Question 26

During exercise, increased muscle contraction helps return more blood to the heart. This would lead to

Answer 26

Increased stroke volume

Question 27

What causes atrial systole?

Answer 27

When the electric impulse is initiated it sends a wave of excitation though the atria and this is what causes atrial systole

Question 28

What causes Ventricular systole

Answer 28

When the electrical impulse reaches the purkinje fibres it conducts the impulse to the ventricles which causes Ventricular systole

Question 29

On a ECG complex what does the P wave represent?

Answer 29

Atrial Depolarisation

Question 30

On a ECG complex what does the QRS complex represent?

Answer 30

Ventricular depolarisation

Question 31

On a ECG complex what does the T wave represent?

Answer 31

Ventricular repolarization