Vascular anatomy of the gastrointestinal tract.

The blood supply of the gastrointestinal system has intramural and extramural components. The intramural vascular distribution is generally well developed with plexuses in the different layers of the bowel wall and with specializations in the liver, small intestine and gastroesophageal junction, adapted to the function of these organs. The extramural arterial supply for the oesophagus is derived from the thoracic aorta or its major branches. Blood supply to the abdominal organs is provided by three major unpaired vessels arising from the abdominal aorta, namely the coeliac trunk and the superior and inferior mesenteric arteries. The branches of these vessels form anastomotic systems that provide a rich blood supply to the adjoining organs. In many areas the systems overlap while in other regions linkages are limited. Interrelations and weak points are of significant clinical importance. As well as this, there is a great individual variability in the anatomy of the gastrointestinal vasculature. Copyright 2001 Harcourt Publishers Ltd.