Step-by-step explanation:
The heart pumps blood in different parts of the body. it occurs by the rhythmic contractions and relaxations of auricles and ventricles. it is called heartbeat. The heart beat rate in normal adukt is 72 - 80 times per min.
When the auricles contract, deoxygenated blood from right auricle passes into right ventricle by opening the tricuspid valve. similarly, pure blood from the left auricle enters to the left ventricle by opening the bicuspid valve.
After this, when the ventricles contract, auricles relax. In this condition, impure blood from different parts of the body are brought into the right auricle through the venacavas.At tge same time, pure blood from the lungs is broght into the left auricle through pulmonary veins. In the mean time, the impure blood of the right ventricle passes to the lungs through the pulmonary artery for purification. The pure blood of left ventricle is pumped into different parts of a body through aorta.
hope it helps..