Vestibule of the middle course
The vestibule of the middle passage is a complete anatomical region limited by the mucous membrane of the sinus of the superior vena cava. This vessel in the lower third enters the common cavity of the hepatobile duct. In this case, venous blood flows through it in one direction and at the same time through lymphatic vessels in another, opposite direction. The duodenum is also divided into three anatomical divisions - the bulb, the body and the tail of the intestine. However, it is conventionally called the bulb, body and tail, since the last part of them is the largest in length.