the cardiac cycle

Question 1

step one of cardiac cycle

Answer 1

CARDIAC DIASTOLE
entire heart is relaxed
blood returns to the heart thru pulmonary vein and vena cava
as the atria fill pressure within them rises
av valves open and blood flows passively into the ventricles without systole

Question 2

stage two cardiac cycle

Answer 2

ATRIAL SYSTOLE
walls of atria contract and volume decreases meaning atrial pressure increases to above that of the ventricle
this forces the atrial venricular valve to open
blood flows into ventricle
ventricle is in diastole during this

Question 3

stage three cardiac cycle

Answer 3

VENTRICULAR SYSTOLE
walls of ventricle contract and volume decreases meaning the pressure decreases
the semi lunar valves are forced open as the pressure increases to above the aorta and pulmonary artery blood is forced into the arteries and out of the heart