- a.venticle relax to make blood of heart
- b.atrium relaxes to make blood enter the heart then contracts to push blood into ventricle
When the antrium contracts, the ventricle relaxes and it occurs conversely antrium contractions is generated by nerves stimulation accepted by Keith-Flack node and spread out to weinchebah nerves. Ventricular contraction is caused by the stimulation accepted by tawana node and passed on to his bundle node.
The right and left atrium relax to accept blood from vein at the same time. The right atrium receives blood from two vena cava, while left atrium receives blood from pulmonary vein. The two atriums then contract thoroughly to push the blood into the relaxed ventricle. After resting for a while, the two ventricles contract to push the blood into aorta and pulmonary artery.
The reserve flow of blood into atrium is prevented by the closing of tricuspid and bicuspid valve creating sound “lup”. After fully blood into ventricle within the artery is prevented by the closing of semi lunar valve creating the sound of “dup”