|simple diagram of the NORMAL adult circulation|
The above diagram shows a simple flow for the blood circulation of an adult from 1 year onwards.
The deoxygenated blood from the different parts of the body including the extremities and internal organs passes through the inferior and superior vena cava for it to enter the right atrium. The right atrium will then pump the blood through the right ventricle passing a valve called the tricuspid valve. Then, the right ventricle will again pump the blood or it to pass the pulmonary artery and go to the lungs. The right ventricle is connected with the pulmonary artery by a pulmonic valve. The pulmonary artery is the only artery that carries deoxygenated blood.
From the lungs, the blood will then be oxygenated since there is gas exchange that would take place. The oxygenated blood will travel through the pulmonary vein and enter the left atruim. The blood inside the left atrium will then be pumped down to the left ventricle passing the mitral valve (also known as the bicuspid valve). The left ventricle will then pump the blood passing the aortic valve and going to the aorta. There, the blood will be distributed back to all the body parts through the arteries.