cardiac cycle

deoxy blood goes to vena cava

goes to right atrium, atrio-ventricular valves open

goes into right ventricle, semi-lunar valves open

blood goes out pulmonary artery to lungs

oxy blood goes in pulmonary veins

goes to left atrium, atrio-ventricular valves open

goes into left ventricle, semi-lunar valves open

ventricles contract from apex upwards

goes out aorta and into the body

atrial systole - atria contract n push blood into ventricles

ventricle systole - ventricles contract, increasing pressure in V to push blood out

Atrial systole

ventricle systole

cardiac diastole - elastic recoils as heart relaxes causes low pressure in heart, refills chambers w blood from veins