Also see user session. In telecommunication, a session is a series of interactions between two communication end points that occur during the span of a single connection.
The path of blood through the heart begins with the right atrium receiving blood, which has circulated through most of the body. This blood is relatively low in oxygen because most of it has already been delivered to different organs and tissues.
After the blood has supplied cells throughout the body with oxygen and nutrients, it returns deoxygenated blood to the right atrium of the heart. The deoxygenated blood shoots down from the right atrium to the right ventricle. The heart then pumps it out of the right ventricle and into the pulmonary arteries to begin pulmonary circulation. The blood moves to the lungs, exchanges carbon dioxide for oxygen, and returns to the left atrium.