Teniae coli
Taeniae coli
- Related terms: Taeniae coli
Definition
The teniae coli are three thickened longitudinal bands of smooth muscle formed by condensation of the outer longitudinal layer of the muscularis externa of the large intestine. They are characteristic features of the caecum and colon and are absent in the rectum, where the longitudinal muscle layer becomes continuous around the bowel wall.
Each teniae is approximately 12 mm wide and extends from the base of the vermiform appendix to the rectosigmoid junction. Because the teniae coli are shorter than the remainder of the intestinal wall, they exert a longitudinal pull on the colon, producing the characteristic sacculations known as haustra (sacculi).
Teniae coli | Position | Anatomical relationship | |
Posteromedial | Corresponds to the attachment of the mesocolon along the attached border of the intestine | ||
Anterior and largest band | Related to the attachment of the greater omentum along the transverse colon; lies anteriorly on the ascending, descending, iliac, and sigmoid colon | ||
Tenia libera (free tenia) | Lateral / free border | Located on the medial side of the ascending and descending colon and on the inferior surface of the transverse colon | |
Functional significance
The teniae coli are shorter than the other layers of the intestinal wall, causing the colon to become puckered into a series of sacculations known as haustra. These haustra are responsible for the characteristic segmented appearance of the large intestine.
If the teniae are dissected away or their longitudinal tension is removed, the colon elongates and the sacculated appearance disappears.
Clinical correlate
The three teniae coli converge at the base of the vermiform appendix. Following any taenia coli on the caecum will lead directly to the appendiceal base.
References
Wei Z, Yao J, Wang S, Liu J, Summers RM. Automated teniae coli detection and identification on computed tomographic colonography. Med Phys. 2012 Feb;39(2):964-75.
Standring, S. (2015) Grays Anatomy: The Anatomical Basis of Clinical Practice. 41st edn. London: Churchill Livingstone Elsevier. Chapter 66, Large intestine.
