Arteries that supply the intestines arise from the aorta. Veins that drain the intestines . A) enter the inferior vena cava directly B) empty into the hepatic veins C) ultimately drain into the hepatic portal vein D) join to form the common intestinal vein that enters the vena cava

There are two venous systems that drain abdominal structures – the portal venous system and the systemic venous system. The portal system transports venous blood to the liver for processing, whilst the systemic venous system returns blood to the right atrium of the heart.

In this article, we shall consider the anatomy of these two venous systems – the major vessels involved, their anatomical course, and their tributaries.Inferior Vena Cava

The inferior vena cava is the common convergence of venous drainage from all structures below the diaphragm. It is located on the posterior abdominal wall; anteriorly to the vertebral column and to the right of the abdominal aorta.

The vessel is formed by the union of the common iliac veins at the L5 vertebral level. Its ascends superiorly, and leaves the abdomen by piercing the central tendon of the diaphragm at the T8 level (the caval hiatus). Within the thorax, the inferior vena cava drains into the right atrium of the heart.

During its long course, the inferior vena cava shares an anatomical relationship with numerous abdominal structures – including the right common iliac artery, the root of the mesentery, the head of the pancreas, the bile duct, the portal vein and the liver.

Explanation:

a = executive branch; b = judicial branch