QS Study

Transerve Colon is the middle part of the large intestine, passing across the abdomen from right to left below the stomach. It is a hollow tube about 2.5 inches (6 cm) in diameter and around 18 inches (46 cm) in length. The gastrocolic ligament also attaches the transverse colon to the stomach.

Blood supply to transverse colon – Because of its significance, the transverse colon requires a steady supply of oxygenated blood. This comes by way of two arteries.

Arteries

(A) Proximal two thirds – By the middle colic artery, branch of the superior mesenteric artery. The medial colic artery branches off the superior mesenteric artery, and it serves most of this part of the large intestine.

(B) Distal third – By left colic artery, branch of the inferior mesenteric artery. Ascending branch of the left colic artery (a branch of IMA) supplies distal 1/3

Fig: Blood Supply – The major arteries and veins supplying the colon

Veins

The veins correspond to the arteries and drain into the superior and inferior mesenteric veins. It via similarly named veins to the splenic vein to the portal venous system

Nerve supply

  • Proximal 2/3rd – sympathetic and vagus nerves through superior mesenteric plexus.
  • Distal 1/3rd – Sympathetic and parasympathetic pelvic splanchnic nerves through the inferior mesenteric plexus.

Development

(i) Proximal 2/3 rd – From midgut. The proximal two-thirds of the ascending colon is innervated by sympathetic and parasympathetic nerves from the superior mesenteric plexus.

(ii) Distal 1/3 rd – From hindgut. The distal third in innervated by sympathetic and parasympathetic fibers from the inferior mesenteric plexus.