Quick Facts
The transverse mesocolon is the fold of peritoneum attaching the transverse colon to the posterior abdominal wall (Dorland, 2011).
Related parts of the anatomy
Structure/Morphology
The mesentery is an expansive double fold of visceral peritoneum, which is a continuation of the parietal peritoneum lining the posterior abdominal wall. The mesentery extends anteriorly in the abdomen to reach the organs. The part of the mesentery that extends to the transverse colon is referred to as the transverse mesocolon. It envelopes the transverse colon as the serosa, therefore, suspending the transverse colon for the posterior abdominal wall.
The transverse mesocolon houses the vessels which supply the transverse colon. These vessels travel in the transverse mesocolon, spreading and branching out as they get closer to the transverse colon. The arteries form supportive anastomosis as the mesentery envelopes the colon. The proximal two thirds of the transverse colon is a midgut derivative; therefore, it is supplied and drained by colic branches of the superior mesenteric vessel, while the distal third of the transverse colon is a hindgut derivative and is supplied and drained by colic branches of the inferior mesenteric vessels.
Innervation follows a model of distribution similar to the arterial blood supply. The celiac and superior mesenteric plexuses supply sympathetic and parasympathetic innervation to the proximal two thirds of the transverse colon, while the inferior mesenteric and hypogastric plexuses provide a sympathetic and parasympathetic supply to the distal transverse colon.
The mesentery houses a lymphatic system along and the drainage is distributed amongst various lymph nodes group within the mesentery such as the epicolic, paracolic, intermediate colic, and preterminal colic node groups. This distribution is based on the arterial supply to the various aspects of the colon.
Function
The transverse mesocolon suspends the transverse colon from the posterior abdominal wall and protects the passage of the vessels, nerves, and lymphatics from the posterior abdominal wall.
List of Clinical Correlates
—Mesenteric lymphadenitis
—Vascular mesenteropathies
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
