Arteria lienalis: The blood vessel that supplies the spleen
The arteria lienalis, also known as the splenic artery, is an unpaired artery that arises from the celiac trunk, the main branch of the abdominal aorta. It is the longest branch of the celiac trunk and it supplies oxygenated blood to the spleen, as well as parts of the stomach and pancreas.
The arteria lienalis follows a tortuous course along the upper border of the pancreas, passing behind the stomach and through the splenorenal ligament. It reaches the hilum of the spleen, where it divides into two terminal branches: superior and inferior. Each terminal branch further splits into four to six segmental branches that enter the parenchyma of the spleen.
Along its course, the arteria lienalis gives off several branches to the pancreas and stomach. These include:
- The pancreatic branches: dorsal, transverse, and greater pancreatic arteries, and the artery to tail of pancreas. These arteries supply the different parts of the pancreas.
- The short gastric arteries: four or five small arteries that arise near the end of the arteria lienalis and supply the upper part of the greater curvature and fundus of the stomach.
- The left gastroepiploic artery: a large artery that runs along the middle part of the greater curvature of the stomach, within the greater omentum. It gives off ascending branches to both surfaces of the stomach and anastomoses with the right gastroepiploic artery, a branch of the gastroduodenal artery.
- The posterior gastric artery: a variable artery that may arise from either the arteria lienalis or its left gastroepiploic branch. It supplies the posterior surface of the stomach near its cardiac region.
The arteria lienalis is accompanied by a similarly named vein, the vena lienalis or splenic vein, which drains blood from the spleen, pancreas, and stomach into the hepatic portal vein.
The function of the arteria lienalis is to deliver oxygen-rich blood to the spleen, which is an important organ of the immune system. The spleen performs several functions, such as:
- Filtering the blood and removing old or damaged erythrocytes, platelets, and foreign particles.
- Producing and storing lymphocytes, which are white blood cells that fight infections and produce antibodies.
- Initiating immune responses to antigens that are carried by the blood to the spleen.
- Releasing blood into the circulation in case of hemorrhage or shock.
The arteria lienalis also supplies blood to parts of the stomach and pancreas, which are involved in digestion and metabolism. The stomach produces gastric acid and enzymes that break down food, while the pancreas secretes hormones such as insulin and glucagon that regulate blood glucose levels. The pancreas also produces digestive enzymes that are delivered to the duodenum via the pancreatic duct.
The arteria lienalis is a vital artery that can be affected by various diseases and conditions. Some of these include:
- Splenic artery aneurysm: a bulging or dilation of a weak spot in the wall of the arteria lienalis. This can cause abdominal pain, nausea, vomiting, or rupture and bleeding. Risk factors include hypertension, pregnancy, liver disease, and connective tissue disorders.
- Splenic artery embolism: a blockage of the arteria lienalis by a blood clot or other material that travels from another part of the body. This can cause ischemia or infarction of the spleen, leading to severe pain, fever, shock, or splenic rupture.
- Splenic artery occlusion: a narrowing or closure of the arteria lienalis due to atherosclerosis, inflammation, trauma, or compression by a tumor or cyst. This can also result in reduced blood flow to the spleen and its complications.