A major artery in the upper abdomen is notable for its characteristic three-branch structure. This vessel, the celiac trunk, is the primary arterial supply for the organs of the upper digestive system. Understanding its branching pattern provides a clear map of this region’s circulation.
Locating the Celiac Trunk
The celiac trunk is the first major unpaired branch to emerge from the front of the abdominal aorta. This short, wide vessel is 1.5 to 2 centimeters long and originates just as the aorta passes through an opening in the diaphragm called the aortic hiatus. This emergence point corresponds to the level of the twelfth thoracic vertebra (T12).
From its origin, the celiac trunk projects forward and slightly downward. It is situated in the superior part of the abdominal cavity, positioned above the pancreas. Its location deep within the abdomen, behind the stomach and a peritoneal fold called the lesser omentum, makes it a central distribution point for blood flow, allowing it to supply oxygenated blood to the foregut.
The Left Gastric Artery
The first and smallest of the three branches from the celiac trunk is the left gastric artery. This vessel ascends superiorly and toward the left, aiming for the junction where the esophagus meets the stomach. It then gives off several small esophageal branches that travel upward to supply the abdominal portion of the esophagus.
After supplying the esophagus, the main artery descends along the upper, concave curve of the stomach known as the lesser curvature. As it travels along this path, it provides blood to the adjacent surfaces of the stomach. It forms an anastomosis, or a connection, with the right gastric artery, and this connection creates a continuous arterial loop along the stomach’s lesser curvature.
The Splenic Artery
The largest branch of the celiac trunk is the splenic artery. This vessel has a tortuous course as it travels horizontally to the left. This winding path allows for the movement and distension of the stomach without compromising blood flow. The artery runs along the superior border of the pancreas, posterior to the stomach, on its way to the spleen.
Before reaching the spleen, the splenic artery gives off several branches that supply surrounding structures. It sends pancreatic branches to nourish the body and tail of the pancreas. It also gives rise to the short gastric arteries, which supply the stomach’s fundus, and the left gastro-omental artery, which runs along the greater curvature. The splenic artery ultimately enters the spleen at its hilum, dividing into smaller vessels to perfuse the organ.
The Common Hepatic Artery
The common hepatic artery is a substantial branch that courses to the right side of the abdominal cavity. It travels toward the upper surface of the duodenum. This vessel supplies the liver, gallbladder, and portions of the stomach, duodenum, and pancreas. Its pathway leads it to bifurcate, or divide, into two terminal branches.
The first of these terminal branches is the proper hepatic artery. This artery ascends within the lesser omentum toward the liver. As the primary source of arterial blood for the liver, it divides into right and left hepatic arteries to supply the different lobes of the organ. The proper hepatic artery also gives rise to the cystic artery, which supplies the gallbladder.
The second terminal branch is the gastroduodenal artery. This vessel follows a descending path behind the first part of the duodenum. It supplies blood to the pylorus, which is the final section of the stomach, and the proximal part of the duodenum. The gastroduodenal artery also sends branches to supply the head of the pancreas.