The celiac artery is a blood vessel of the digestive system. It is the largest branch of the abdominal aorta, the major blood vessel of the abdomen, which descends from the heart and ends in the pelvis, where it splits into the right and left iliac arteries. This vessel arises from the front side of the abdominal aorta at approximately the height of the eighth rib, just above T12, the 12th vertebra in the thoracic spine. The function of the celiac artery is to supply blood rich with oxygen and nutrients to the digestive organs situated in the upper portion of the abdomen, including the bottom segment of the esophagus, the stomach, pancreas, liver, spleen, and the duodenum, the uppermost portion of the small intestine.
Alternately known as the celiac trunk, the celiac artery originates a few inches below the xiphoid process of the sternum, or bottom tip of the breastbone, near the midline of the body. With the abdominal aorta running vertically behind it, it is nestled just behind the liver, stomach, and pancreas. Above this point of origin is the heart, and below it, cutting horizontally across the abdominal aorta, is the renal vein, which returns blood to the heart from the kidneys on either side.
From this point, the celiac artery runs forward and downward, dividing almost immediately into three smaller arteries: the left gastric artery, the common hepatic artery, and the splenic artery. The left gastric artery travels back upward and slightly to the left, bringing blood to the lower esophagus and to the top of the stomach, where it meets the right gastric artery along the stomach’s upper curve. Curving away from the celiac artery to the right is the common hepatic artery, which supplies blood to the liver, to the pancreas, to the duodenum, and to the pylorus, which links the stomach to the duodenum. To the left is the splenic artery, which transports blood to the spleen.
While most arteries have a paired vein that cycles deoxygenated blood from the tissue nourished by the artery back to the heart and lungs, the celiac artery does not. Instead, blood from the digestive organs travels to the liver via the hepatic portal vein or a group of smaller capillaries known as the portal venous system, where the organ removes toxins such as alcohol. As much as 75 percent of the liver’s blood flow comes from these vessels and only 25 percent from the hepatic artery, with each contributing roughly 50 percent of the liver’s oxygen supply. The deoxygenated blood from the celiac and hepatic arteries then returns to the heart and lungs via the inferior vena cava, the large vein of the abdomen that runs parallel to the abdominal aorta.