Splenic vein | |
---|---|
Details | |
System | Hepatic portal system |
Drains from | Trabecular vein of spleen |
Source | Short gastric veins, left gastroepiploic vein, pancreatic veins, inferior mesenteric vein |
Drains to | Hepatic portal vein |
Artery | Splenic artery |
Identifiers | |
Latin | vena lienalis |
MeSH | D013162 |
TA98 | A12.3.12.028 |
TA2 | 5123 |
FMA | 14331 |
Anatomical terminology |
In human anatomy, the splenic vein (formerly the lienal vein) is a blood vessel that drains blood from the spleen, the stomach fundus and part of the pancreas. It is part of the hepatic portal system.
The splenic vein is formed from small venules that leave the spleen. It travels above the pancreas, alongside the splenic artery. It collects branches from the stomach and pancreas, and most notably from the large intestine (also drained by the superior mesenteric vein) via the inferior mesenteric vein, which drains in the splenic vein shortly before the origin of the hepatic portal vein. The splenic vein ends in the portal vein, formed when the splenic vein joins the superior mesenteric vein.
The splenic vein can be affected by thrombosis, presenting some of the characteristics of portal vein thrombosis and portal hypertension but localized to part of the territory drained by the splenic vein. These include varices in the stomach wall due to hypertension in the short gastric veins and abdominal pain. This results in gastric varices, in which the treatment of choice would be splenectomy. The most common cause for splenic vein thrombosis is both chronic and acute pancreatitis. [1] [2]
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e., it has both an endocrine and a digestive exocrine function. 99% of the pancreas is exocrine and 1% is endocrine. As an endocrine gland, it functions mostly to regulate blood sugar levels, secreting the hormones insulin, glucagon, somatostatin and pancreatic polypeptide. As a part of the digestive system, it functions as an exocrine gland secreting pancreatic juice into the duodenum through the pancreatic duct. This juice contains bicarbonate, which neutralizes acid entering the duodenum from the stomach; and digestive enzymes, which break down carbohydrates, proteins and fats in food entering the duodenum from the stomach.
The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents. Approximately 75% of total liver blood flow is through the portal vein, with the remainder coming from the hepatic artery proper. The blood leaves the liver to the heart in the hepatic veins.
Esophageal varices are extremely dilated sub-mucosal veins in the lower third of the esophagus. They are most often a consequence of portal hypertension, commonly due to cirrhosis. People with esophageal varices have a strong tendency to develop severe bleeding which left untreated can be fatal. Esophageal varices are typically diagnosed through an esophagogastroduodenoscopy.
Portal hypertension is defined as increased portal venous pressure, with a hepatic venous pressure gradient greater than 5 mmHg. Normal portal pressure is 1–4 mmHg; clinically insignificant portal hypertension is present at portal pressures 5–9 mmHg; clinically significant portal hypertension is present at portal pressures greater than 10 mmHg. The portal vein and its branches supply most of the blood and nutrients from the intestine to the liver.
Gastric varices are dilated submucosal veins in the lining of the stomach, which can be a life-threatening cause of bleeding in the upper gastrointestinal tract. They are most commonly found in patients with portal hypertension, or elevated pressure in the portal vein system, which may be a complication of cirrhosis. Gastric varices may also be found in patients with thrombosis of the splenic vein, into which the short gastric veins that drain the fundus of the stomach flow. The latter may be a complication of acute pancreatitis, pancreatic cancer, or other abdominal tumours, as well as hepatitis C. Gastric varices and associated bleeding are a potential complication of schistosomiasis resulting from portal hypertension.
The celiacartery, also known as the celiac trunk or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) in humans, it is one of three anterior/ midline branches of the abdominal aorta.
In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.
In human anatomy, the splenic artery or lienal artery, an older term, is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. It is known for its tortuous path to the spleen.
In human anatomy, the superior mesenteric vein (SMV) is a blood vessel that drains blood from the small intestine. Behind the neck of the pancreas, the superior mesenteric vein combines with the splenic vein to form the portal vein that carries blood to the liver. The superior mesenteric vein lies to the right of the similarly named artery, the superior mesenteric artery, which originates from the abdominal aorta.
In human anatomy, the inferior mesenteric vein (IMV) is a blood vessel that drains blood from the large intestine. It usually terminates when reaching the splenic vein, which goes on to form the portal vein with the superior mesenteric vein (SMV).
Portal vein thrombosis (PVT) is a vascular disease of the liver that occurs when a blood clot occurs in the hepatic portal vein, which can lead to increased pressure in the portal vein system and reduced blood supply to the liver. The mortality rate is approximately 1 in 10.
The hepatic artery proper is the artery that supplies the liver and gallbladder. It raises from the common hepatic artery, a branch of the celiac artery.
In human anatomy, the hepatic portal system or portal venous system is the system of veins comprising the portal vein and its tributaries. The other portal venous systems in the body are the renal portal system, and the hypophyseal portal system.
The middle colic artery is an artery of the abdomen; a branch of the superior mesenteric artery distributed to parts of the ascending and transverse colon. It usually divides into two terminal branches - a left one and a right one - which go on to form anastomoses with the left colic artery, and right colic artery (respectively), thus participating in the formation of the marginal artery of the colon.
The superior pancreaticoduodenal artery is an artery that supplies blood to the duodenum and pancreas.
In the anatomy of the human digestive tract, there are two colic flexures, or curvatures in the transverse colon. The right colic flexure is also known as the hepatic flexure, and the left colic flexure is also known as the splenic flexure. Note that "right" refers to the patient's anatomical right, which may be depicted on the left of a diagram.
The greater omentum is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature of the stomach, passing in front of the small intestines and doubles back to ascend to the transverse colon before reaching to the posterior abdominal wall. The greater omentum is larger than the lesser omentum, which hangs down from the liver to the lesser curvature. The common anatomical term "epiploic" derives from "epiploon", from the Greek epipleein, meaning to float or sail on, since the greater omentum appears to float on the surface of the intestines. It is the first structure observed when the abdominal cavity is opened anteriorly.
The gastrosplenic ligament is part of the greater omentum extending between the stomach and the spleen. It contains several blood vessels.
In the circulatory system of vertebrates, a portal venous system occurs when a capillary bed pools into another capillary bed through veins, without first going through the heart. Both capillary beds and the blood vessels that connect them are considered part of the portal venous system.
The superior mesenteric vessels are composed of the superior mesenteric artery and the superior mesenteric vein.