Anatomy: Blood Supply to the Abdomen

Anatomy of the Abdomen: Blood Supply to the Abdomen

The abdomen is a region of the human body that contains the majority of internal organs, including the stomach, intestines, pancreas, spleen, kidneys, and reproductive organs. Given the importance of these organs, the abdomen requires a complex and extensive network of arterial and venous blood vessels for proper functioning.

Arterial Supply

The abdominal aorta, a continuation of the thoracic aorta, is the primary source of blood supply to the abdomen and pelvis. The aorta gives rise to several branches that supply various organs in the region. The celiac trunk, which arises from the abdominal aorta at T12, supplies the foregut gastrointestinal viscera and divides into three major branches: the left gastric, splenic, and common hepatic arteries. The superior mesenteric artery (SMA), which originates from the abdominal aorta at L1, supplies blood to the midgut organs, including the distal duodenum to the proximal 2/3 of the transverse colon. The inferior mesenteric artery (IMA), which arises from the abdominal aorta at L3, provides blood to the hindgut organs, such as the distal 1/3 of the transverse colon to the rectum.

Venous Drainage

The venous drainage of the abdomen is carried out by the portal venous system and the systemic venous system. The portal venous system transports venous blood from the abdominal vasculature to the liver, while the systemic venous system returns blood to the right atrium of the heart via the inferior vena cava.

Stomach

The stomach is supplied by the branches of the celiac trunk, which include the right and left gastric, right and left gastro-omental, short gastric, and pancreatic branches. The left gastric artery gives rise to the esophageal branches and continues as the lesser curvature of the stomach, while the lesser curvature of the stomach is supplied by the right gastric artery. The greater curvature of the stomach is supplied by the left gastroepiploic artery, and the fundus of the stomach is supplied by the short gastric arteries.

Intestines

The intestines, including the small and large intestines, receive their blood supply from the superior mesenteric artery, which branches from the abdominal aorta at L1. The SMA provides the inferior pancreaticoduodenal artery, jejunal and ileal arteries, middle and right colic arteries, and ileocolic artery, which supply the jejunum, ileum, transverse colon, ascending colon, appendix, cecum, and ileum.

Pancreas

The pancreas is supplied by the splenic artery, which branches off the celiac trunk at T12, and the gastroduodenal artery, which branches from the SMA at L1. The splenic artery gives off several pancreatic branches that supply the body and tail of the pancreas, while the gastroduodenal artery gives off the superior pancreaticoduodenal artery, which delivers arterial blood to the head of the pancreas.

Spleen

The spleen is supplied by the splenic artery, which branches off the celiac trunk at T12.

Kidneys

The kidneys receive their blood supply from the renal arteries, which branch off the abdominal aorta near the level of the superior mesenteric artery.

Reproductive Organs

The uterus is supplied by the uterine arteries, and the vagina is supplied by the vaginal, internal pudendal, and uterine arteries. The vaginal venous plexus is responsible for draining the vagina.

Liver and Gallbladder

The liver and gallbladder are the only organs in the abdomen that are not supplied by the abdominal aorta. They receive their blood supply from the portal vein, which drains blood from the intestines and spleen.

In conclusion, the abdomen is supplied by an extensive network of arteries and veins, all of which are branches of the abdominal aorta and inferior vena cava. Understanding the blood supply to the abdomen is essential for medical professionals in diagnosing and treating various conditions affecting these organs.