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.
The coronary circulation consists of the coronary arteries, which branch off of the aorta and carry oxygen-rich blood to the heart muscle; and coronary veins, which carry deoxygenated blood to the coronary sinus, which empties into the right atrium.