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.
Most veins in the body carry deoxygenated blood which is returning from the tissues. After this blood reaches the heart, it goes through the right side of the heart, which pumps the deoxygenated blood through the pulmonary artery (artery=away from the heart) and to the lungs.