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.
Deoxygenated blood entering the heart through veins from the tissues of the body first enters the heart through the right atrium before being pumped into the right ventricle. The right atrium is one of the two atria of the heart, which function as receiving chambers for blood entering the heart.eoxygenated blood enters the right atrium through three major veins: the superior and inferior vena cava and the coronary sinus. The superior vena cava returns all of the blood to the heart from tissues superior to the heart in the head, neck, arms and upper thorax.