Abdominal arteries:
Aorta terminates as bifurcation into R and L iliac arteries. 3 unpaired branches come off of aorta on its path from diaphragm to bifurcation.
- Celiac artery (celiac trunk): this supplied the foregut in embryo (stomach, duodenum, esophagus). Has 3 major branches:
- Left gastric artery: lesser curvature of stomach.
- Splenic artery: Runs behind stomach to supply spleen.
- Common Hepatic artery. Splits into gastroduodenal artery and propery hepatic artery.
- Superior mesenteric artery (more inferior): supplies small intestine and most of large intestine. Forms intestinal branches.
- Ileocolic (ileocecal) supplies terminal part of ilum, cecum, and appendix.
- Right colic artery: supplies ascending colon.
- Middle colic artery: supplies transverse colon.
- Inferior pancreaticoduodenal artery: inferior supply to pancreas / duodenum.
- All of these arteries are interconnected by the marginal artery of Drummond. This connection is important for collateral circulation. Connects branches of both superior mesenteric and inferior mesenteric arteries.
- Inferior mesentery artery (most inferior): supplies last portion of large intestine and part of rectum.
- Left colic artery: majority of descending colon.
- Sigmoidal artery: supplies sigmoidal colon.
- Superior rectal artery: supplies rectum. Always furthest to the right.
- “Mesentery” arteries travel within the mesentery.
Hepatic portal venous system:
- Begins at the venous ends of capillaries in the organs of the GI tract and ends at the venous sinusoids in the liver.
- The portal vein is formed by the joining of the splenic vein within the superior mesenteric vein. The inferior mesenteric vein usually joins the splenic vein.
- Superior mesenteric vein
- Inferior mesenteric vein.
- Splenic vein
- Splenic vein joins with inferior mesenteric veinà then joined by superior mesenteric vein to become the portal vein.
Portal hypertension:
- Occurs when portal circulation through liver is obstructed by liver disease (cirrhosis) or tumor.
- Portal veins do not have valves, thus allowing flow in each direction.
- The high portal pressure promotes the enlargement (varices) of alternate pathways to the caval system. Result is varicose veins (enlarged veins). 4 spots where these occur: at portal-systemic anastomoses:
- Esophageal varices: between esophageal branch of left gastric portal vein and esophageal branches to azygous (systemic veins).
- Hemorrhoids: between superior rectal branch of inferior mesenteric vein (portal) and the middle / inferior rectal vein to the internal iliac (systemic).
- Caput medusae: between paraumbilical (in falciform ligament) branch of portan and the superior / inferior epigastric veins (systemic).
- Retroperitoneal varices (veins of Retzius): between colic / duodenal / pancreatic veins and the lumbar / renal veins to the inferior vena cava (systemic).
