4 Cardiac Cycle

Question 1

What is the systemic circulation?

Answer 1

Blood pressure circulating the body

Question 2

What is the pulmonary circulation?

Answer 2

Blood pressure circulating the lungs

Question 3

What is systole?

Answer 3

The contraction and ejection of blood from the ventricles

Question 4

What is diastole?

Answer 4

The relaxation and filling of the ventricles

Question 5

How much blood is pumped around the body in 1 minute?

Answer 5

5 litres

Question 6

Name the 4 valves that determine blood flow through the heart

Answer 6

Tricuspid valve - right in
Pulmonary valve - right out
Mitral valve - left in
Aortic valve - left out

Question 7

How and what muscles do the mitral and tricuspid valves attach to?

Answer 7

Attach to papillary muscles via the chordae tendineae

Question 8

What is the function of chordae tendineae?

Answer 8

To prevent the inversion of the valves on systole

Question 9

Where are the pacemaker cells located?

Answer 9

Sinoatrial node

Question 10

When does atrial systole occur?

Answer 10

When an action potential spreads across the atria

Question 11

Describe the process that causes ventricular contraction

Answer 11

1) An action potential is generated by pacemaker cells
2) The action potential spreads across the atria and reaches the atrioventricular node
3) The action potential is delayed at the AV node
4) The excitation spreads down the septum through the bundle of His
5) The activity spreads through the ventricular myocardium from the endcardial to the epicardial
6) The ventricle contractions from the apex up in sync