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.
The extrinsic pathway is activated when being exposed to tissue factor from tissue injury or the addition of thromboplastin to blood, and involves clotting factor VII. The two pathways meet at the point of clotting factor X activation to lead the final common pathway.