The gastrointestinal tract extends from mouth to the rectum, and enables us to gain nutrients from the food we eat. Gut associated lymphoid tissue performs immunological function by eliminating bacteria and intraluminal toxin and protects the intestinal mucosa from invading pathogens. It has various parts that are specialized to absorb certain nutrients and vitamins e.g. vitamin B12 and bile salts are absorbed in the terminal ileum. The bowel develops in three separate sections, namely the foregut, midgut and hindgut supplied by separate nerves, arteries, and veins. This article will describe the celiac or coeliac trunk (which supplies the foregut), including its branches, and clinical relevance. We will conclude with some review questions to test the reader’s understanding of the article content.
Three major divisions of the gastrointestinal tract are foregut, midgut and hindgut. The foregut extends from the mouth to the major duodenal papilla (where the ampulla of Vater empties into the duodenum). The midgut extends from this point to two thirds of the way along the transverse colon. The hindgut runs from this point to the superior rectum. The coeliac trunk (or celiac trunk) supplies the foregut, superior mesenteric artery supplies the midgut and the inferior mesenteric artery supplies the hindgut. The coeliac artery arises from the abdominal aorta as soon as it passes through the diaphragm at the level of the twelfth thoracic vertebrae. It gives off three major branches i.e. the left gastric, common hepatic and splenic. In the same sense, the sympathetic input to the foregut, midgut and hindgut are supplied by the greater, lesser and least thoracic splanchnic nerves respectively. The parasympathetic input to the whole bowel as far as the splenic flexure is supplied by the vagus nerve (cranial nerve X).
Left Gastric Artery- This is the smallest and the first branch that arises from the coeliac trunk and passes into the lesser omentum (which connects the lesser curvature of the stomach to the liver) along the lesser curvature of the stomach, to supply its superior portion. Here it anastomoses with right gastric artery. Some branches of the left gastric artery also supply the inferior part of the oesophagus.
Common Hepatic Artery- This branch arises from the coeliac trunk and runs towards the right towards the liver and in order to enter the lesser sac. This artery gives off the right gastric artery above the first part of the duodenum, which runs between the peritoneal layers of lesser omentum to supply the lesser curvature of the stomach and anastomoses with the left gastric artery. The common hepatic artery then divides into the hepatic artery proper and the gastroduodenal artery. At the porta hepatis the hepatic artery proper divides into the right and left hepatic arteries and enter the liver. These vessels then divide further into lobar arteries. The gastroduodenal artery arises posterosuperior to the 1st part of duodenum, it gives off the right gastroepiploic artery which supplies the greater curvature of the stomach. Gastroduodenal artery terminates as the superior pancreaticoduodenal artery, which supplies the head of the pancreas and the anterior and posterior surfaces of the duodenum. It anastomose with the inferior pancreaticoduodenal artery( first branch of the superior mesenteric artery).
Splenic Artery- This is a tortuous branch that runs towards the hilum of the spleen. On the way it has a number of arteries that supply the neck, body and tail of the pancreas. It also gives off the left gastroepiploic artery that supplies the greater curvature of the stomach, and anastomoses with the right gastroepiploic artery. The splenic artery also gives off the short gastric arteries before it reaches the hilum of the spleen. It runs within the gastrosplenic ligament in order to supply the fundus of the stomach as well as the superior part of the greater curvature of the stomach. It anastomoses with the left gastric artery.
Click on the above diagram to see all the branches of the celiac trunk