The Cardiac Cycle

Question 1

name the 5 stages of the cardiac cycle in order

Answer 1

1. late diastole
2. atrial systole
3. isovolumic ventricular contraction
4. ventricular ejection
5. isovolumic ventricular relaxation

Question 2

what happens during late diastole?

Answer 2

both sets of chambers relax and the ventricles fill passivly

Question 3

describe what happens in atrial systole

Answer 3

atrial contraction forces a small amount of additional blood into the ventricles

Question 4

describe what happens during ventricular contraction

Answer 4

the first phase of ventricular contraction pushes the atrial ventricular valves closed but doesn’t create enough pressure to open the semilunar valves

Question 5

what happens during ventricular ejection?

Answer 5

the ventricular pressure rises and exceeds the pressure in the arteries, opening the semi-lunar valves and ejecting the blood

Question 6

describe what happens in the isovolumic ventricular relaxation

Answer 6

the ventricles relax, the pressure inside them falling. this makes the blood flow back into the cusps of the semi-lunar valves snapping the closed.

Question 7

what could cause a murmur after the mitral and tricuspid valves closing?

Answer 7

stenosis of the aorta/pulmonary artery or regurgitation through the mitral/tricuspid valve

Question 8

what would cause a murmur after the aortic or pulmonary valves closing?

Answer 8

stenosis of the mitral/tricuspid valve or regurgitation through the aortic/pulmonary

Question 9

what does septal defect sound like?

Answer 9

a continuous sound over the lub dub

Question 10

what causes a septal defect?

Answer 10

when one of the holes in the heart hasn’t closed properly so blood is flowing through a part of the heart where it shouldn’t be.

Question 11

what can prevent the valves from opening and closing?

Answer 11

calcification of the valves