The Cardiac Cycle

Question 1

What’s the relaxation phase of the heart

Answer 1

Diastole

Question 2

What’s the contraction phase of the heart

Answer 2

Systole

Question 3

What happens during the diastole phase of the cardiac cycle

Answer 3

blood returns to the heart from the pulmonary vein and the vena cava

as the atria fill the pressure in them rises

when the pressure exceeds that in the ventricles the av valves open allowing the blood to pass into the ventricles

SL valves close to prevent the blood leaving the heart

Question 4

What happens during atrial systole? ( contraction of atria)

Answer 4

Atria contract to push remaining blood into ventricles

Semi lunar valves closed

Left and right atrioventricular valves are open

Blood pumped from atria to ventricles

Ventricles remain relaxed

Question 5

What happens during ventricular systole? ( contraction of the ventricles )

Answer 5

Semi lunar valves open

Left and right atrioventricular closed, as increase pressure, preventing backflow of blood

Ventricles contract and wall thickens - ventricles have a thick muscular walls which mean they contract around the body

Atria relaxed. Ventricles contract, pushing blood away from heart through pulmonary arteries and the aorta

Question 6

What does the atrioventricular valves do

Answer 6

Between LA and LV and the RA and RV.

Prevents backflow of blood when contraction of the ventricles means that ventricular pressure exceeds atrial pressure

Closure of these ensures that, when the ventricles contract, blood within them moves to the aorta and pulmonary artery rather than back to the atria

Question 7

What does the semi lunar valves do

Answer 7

In the aorta and pulmonary artery

Prevent backflow of blood into ventricles when the pressure in these vessels exceeds that in the ventricles

Question 8

What do the pocket valves do

Answer 8

In veins

Ensure that when the veins are squeezed blood flows back towards the heart rather then away from it

Question 9

What’s cardiac output

Answer 9

Volume of blood pumped by one ventricle or the heart in one minute

Question 10

What does cardiac output depend on

Answer 10

Heart rate - rate at which heart beats

Stoke volume - volume of blood pumped out at each beat

Question 11

Name the chamber of the heart that produces the greatest pressure

Answer 11

Left ventricle