DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs. In the human heart there is one atrium and one ventricle for each circulation, and with both a systemic and a pulmonary circulation there are four chambers in total: left atrium, left ventricle, right atrium and right ventricle.
Chambers of the Heart. The heart is composed of four well separated chambers. The two superior chambers are the atria (= entry halls) , and the two inferior chambers are the ventricles (= little bellies). The atria are the receiving chambers, they receive venous blood from systemic and pulmonary circulation and pump it down into the ventricles. The ventricles are the distributing chambers, they pump blood out of the heart into the peripheral circulation.