Human Anatomy - Kotsan I. Y. 2009

Vessels of the Lesser (Pulmonary) Circulation
Branches of the Abdominal Aorta
Unpaired Visceral Branches of the Abdominal Aorta

1. The celiac trunk (truncus coeliacus) is a short vessel, 1.5–2 cm in length, originating from the anterior aspect of the aorta at the level of the XII thoracic vertebra. Above the upper margin of the Pancreas, it divides into three branches: the left gastric, common hepatic, and splenic Arteries (known as the "tripod of Haller" or tripus Halleri).

The left gastric artery (a. gastrica sinistra) ascends superiorly and to the left, running along the lesser curvature of The Stomach between the layers of the lesser omentum, where it anastomoses with the right gastric artery. It gives off esophageal branches (rr. oesophageales) to the abdominal part of the Esophagus. Along its course down the lesser curvature, the left gastric artery sends small branches to the anterior and posterior surfaces of the stomach, which anastomose with Branches of the arteries running along the greater curvature.

The common hepatic artery (a. hepatica communis) extends from the celiac trunk to the right and bifurcates into the proper hepatic artery and the gastroduodenal artery. 1. The proper hepatic artery (a. hepatica propria) courses within the hepatoduodenal ligament toward the porta hepatis, where it divides into right and left branches (r. dexter et r. sinister) supplying the corresponding lobes of the Liver. The cystic artery (a. cystica) branches off the right branch of the proper hepatic artery and supplies the Gallbladder. The right gastric artery (a. gastrica dextra) arises from the main trunk of the proper hepatic artery, travels to the lesser curvature of the stomach, anastomoses with the left gastric artery, and supplies branches to the anterior and posterior gastric walls. 2. The gastroduodenal artery (a. gastroduodenalis) passes posterior to the pylorus of the stomach and divides into the superior posterior and anterior pancreaticoduodenal arteries and the right gastro-epiploic artery. The posterior superior pancreaticoduodenal artery (a. pancreaticoduodenalis superior posterior) runs behind the HEAD of the pancreas, supplies branches to the pancreas and duodenum, and anastomoses with the inferior pancreaticoduodenal artery. The anterior superior pancreaticoduodenal artery (a. pancreaticoduodenalis superior anterior) descends anterior to the head of the pancreas, gives off pancreatic and duodenal branches, and likewise anastomoses with the inferior pancreaticoduodenal artery. The right gastro-epiploic artery (a. gastroepiploica dextra) courses within the greater omentum along the greater curvature of the stomach, anastomoses with its left counterpart, and supplies numerous branches to the stomach and greater omentum.

The splenic artery (a. lienalis, splenica) is the largest branch of the celiac trunk. It courses to the left, running along with the splenic vein posterior to the upper border of the pancreas. Upon reaching the tail of the pancreas, it enters the splenorenal (phrenicolienal) ligament and divides into terminal branches that enter the splenic parenchyma through the hilum. The splenic artery gives off branches supplying the pancreas, stomach, and greater omentum. To the pancreas, the splenic artery sends pancreatic branches (rr. pancreatici) along its entire length into the glandular parenchyma. To the stomach, it supplies short gastric arteries (aa. gastricae breves)—ranging from 3 to 7 small vessels that arise from the terminal segment of the splenic artery, course toward the Cytology/practical/108.html">Fundus of the stomach, and anastomose with other gastric arteries. Near the hilum of the Spleen, the left gastro-epiploic artery (a. gastroepiploica sinistra) arises from the splenic artery, runs to the right along the greater curvature of the stomach, anastomoses with the right gastro-epiploic artery, and gives off gastric and omental branches (rr. gastrici et rr. epiploici) along its path. Near the splenic hilum, the splenic artery further branches into 4–6 terminal splenic branches (rr. splenici) that pierce the hilum and penetrate the substance of the organ.

2. The superior mesenteric artery (a. mesenterica superior) originates from the Abdominal Aorta approximately 1 cm inferior to the celiac trunk, descends posterior to the head of the pancreas toward the ROOT of the mesentery of the Small Intestine, passes between the layers of this mesentery, and gives off the following branches:

a) the inferior pancreaticoduodenal arteries (aa. pancreaticoduodenales inferiores), which branch from the superior mesenteric artery about 2 cm below its origin and course toward the head of the pancreas and duodenum, anastomosing there with the anterior and posterior superior pancreaticoduodenal arteries (branches of the gastroduodenal artery);

b) the jejunal arteries (aa. jejunales) and ileal arteries (aa. ileales), numbering 12–18, which arise from the left circumference of the mesenteric part of the superior mesenteric artery, extend toward the loops of the mesenteric small intestine, and form convex, arch-like anastomoses within the mesentery known as arterial arcades, which ensure a continuous Blood supply to the intestine during peristalsis;

c) the ileocolic artery (a. ileocolica), which runs inferiorly and to the right toward the cecum, giving off along its course the anterior and posterior cecal arteries (aa. caecales anterior et posterior), the appendicular artery (a. appendicularis), and an ascending branch (a. ascendens) to the ascending colon;

d) the right colic artery (a. colica dextra), which arises from the right side of the superior mesenteric artery in its upper third, at the level of the root of the transverse mesocolon, and courses almost transversely to the right toward the medial border of the ascending colon, where it anastomoses with the ascending branch (of the ileocolic artery) and with branches of the middle colic artery.

e) the middle colic artery (a. colica media), which originates from the proximal part of the superior mesenteric artery, extends anteriorly and to the right between the layers of the transverse mesocolon, and divides into right and left branches. The right branch of the middle colic artery anastomoses with the right colic artery, while the left branch forms an anastomosis along the colon with branches of the left colic artery (from the inferior mesenteric artery). The middle colic artery supplies the transverse colon and the upper part of the ascending colon.

3. The inferior mesenteric artery (a. mesenterica inferior) arises from the anterior surface of the abdominal aorta at the level of the III lumbar vertebra, runs retroperitoneally downward and to the left, and gives off the following branches: a) the left colic artery (a. colica sinistra), which supplies the descending colon and the left portion of the transverse colon; b) the sigmoid arteries (aa. sigmoideae)—2 to 3 vessels running within the mesocolon to the sigmoid colon; c) the superior rectal artery (a. rectalis superior), which is the continuation and terminal branch of the inferior mesenteric artery. Descending inferiorly, it divides into two branches: one anastomoses with a branch of the sigmoid artery and supplies the lower part of the sigmoid colon, while the other enters the lesser pelvis and supplies the ampullary part of the rectum.