Ascending colon

The ascending colon is the first major segment of the colon and extends from the cecum in the right iliac fossa to the right colic (hepatic) flexure beneath the right lobe of the liver. It ascends vertically along the right side of the abdominal cavity. The ascending colon is characterized externally by the presence of the taeniae coli, haustra, and omental appendices, which are typical features of the large intestine.

Retroperitoneal structure

The ascending colon is a retroperitoneal structure, with its anterior and lateral surfaces covered by peritoneum, while its posterior surface is usually devoid of peritoneal covering and attached to the posterior abdominal wall.

Function

The ascending colon receives chyme from the cecum and functions primarily in the absorption of water and electrolytes, contributing to the formation of feces.

Blood supply and lymphatics

• The arterial supply of ascending colon is derived mainly from the ileocolic and right colic arteries, branches of the superior mesenteric artery.

• Venous drainage follows the corresponding veins into the superior mesenteric vein.

• Lymphatic drainage is directed to the epicolic, paracolic, ileocolic, and superior mesenteric lymph nodes.

Innervation

Sympathetic innervation is provided through the superior mesenteric plexus, while parasympathetic innervation is supplied by the vagus nerve.