CorpusHuman Anatomy
DigestiveOrgan part

Taeniae coli

Taeniae coli

Also known as: teniae coli, haustra, omental appendices, epiploic appendages

The taeniae coli are three narrow longitudinal bands of smooth muscle on the caecum and colon. Because they are shorter than the bowel wall, they gather it into sacculations called haustra.

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Overview

In the caecum and colon the outer longitudinal layer of the muscularis externa is concentrated into three bands about 1 cm wide, the taeniae coli. Between them the longitudinal layer is very thin. The taenia mesocolica lies along the mesocolic attachment, or posteromedially on the ascending and descending colon. The taenia omentalis lies where the greater omentum attaches to the transverse colon. The taenia libera is free and anterior.

The three bands converge at the base of the appendix and spread out at the rectosigmoid junction to form the continuous longitudinal coat of the rectum. Because the taeniae are shorter than the colonic wall, they pucker it into haustra (sacculations) separated by internal semilunar folds. Small fat-filled peritoneal pouches, the omental (epiploic) appendices, hang along the taeniae.

Location

Caecum and colon, from the base of the appendix to the rectosigmoid junction.

Parts & subdivisions

  1. Taenia mesocolica
    At the mesenteric attachment.
  2. Taenia omentalis
    At the greater omentum attachment on the transverse colon.
  3. Taenia libera
    Free anterior band; follow it to find the appendix.
  4. Haustra and semilunar folds
    Sacculations formed by the shorter taeniae. Haustral contractions churn and slowly move faeces.
  5. Omental appendices
    Fat-filled peritoneal tags along the taeniae, absent from the caecum, appendix and rectum.

Anatomy

Histology

Bundles of smooth muscle (the outer longitudinal layer of the muscularis externa) with myenteric plexus beneath.

Function

  • Shorten the colon and generate haustral and mass-movement contractions.
  • Shape the haustra that slow transit and favour water absorption.

Clinical significance

Surgical and radiological landmarks

At operation, taeniae and omental appendices distinguish colon from small bowel, and following the taeniae leads to the appendix base. On radiographs, haustral folds cross only part of the lumen. In chronic ulcerative colitis haustra are lost ("lead-pipe" colon).

Epiploic appendagitis

Torsion and infarction of an omental appendix causes sharp, localised abdominal pain that mimics diverticulitis or appendicitis. It is self-limiting.

Compiled from standard anatomy and physiology references — see the Digestive System sources. For education only; not medical advice.