| Teniae coli | |
|---|---|
 Iliac colon, sigmoid or pelvic colon, and rectum seen from the front, after removal of pubic bones and bladder. (Taenia coli not labeled, but visible at center.) | |
 Female pelvis and its contents, seen from above and in front. (Taenia coli not labeled, but visible at right.) | |
| Details | |
| Identifiers | |
| Latin | taeniae coli |
| TA98 | A05.7.03.013 |
| TA2 | 2993 |
| FMA | 76487 |
| Anatomical terminology | |
Thetaeniae coli (alsoteniae coli ortenia coli) are three separate longitudinal ribbons (taeniae meaning ribbon in Latin) ofsmooth muscle on the outside of the ascending, transverse, descending and sigmoidcolons. They are visible and can be seen just below theserosa orfibrosa. There are three teniae coli: mesocolic, free and omental taeniae coli. The teniae coli contract lengthwise to produce thehaustra, the bulges in the colon.
The bands converge at the root of thevermiform appendix. At therectosigmoid junction, the taeniae spread out and unite to form the longitudinal muscle layer. In the caecum, the ascending colon, the descending colon and sigmoid colon the positions of these bands are fixed. Thetaenia libera, is placed anteriorly in the caecum, ascending, descending and sigmoid colon, but is placed inferiorly in the transverse colon. Thetaenia mesocolica is present on the posteromedial surface of the caecum, ascending, descending and sigmoid colon, but is placed posteriorly on transverse colon at the site of attachment of transverse mesocolon. Thetaenia omentalis is situated posterolaterally in caecum, ascending, descending and sigmoid colon, but is situated on the anterosuperior surface of transverse colon where layers three and four of thegreater omentum meet the transverse colon. This change in position is due to the twist in transverse colon. These bands correspond to the outer layer of themuscularis externa, in other portions of thedigestive tract.
The teniae coli are regulated by thesacral nerves of thespinal cord, which are under control of theparasympathetic nervous system.[1]
Spaces between the circular bands of taeniae are weak points in the bowel, and are the sites of diverticulosis. Most diverticulosis occur in thesigmoid colon as it is the segment with the highest intraluminal pressure. Diverticulosis does not occur in therectum as the tenia coli become a continuous muscular layer. Diverticulosis can then becomediverticulitis if the patient develops inflammation of the diverticulosis, this whole spectrum of disease is calleddiverticular disease.
The taeniae coli are important anatomical landmarks often used by surgeons performing anappendectomy to localize the appendix. By following the bands inferiorly along the ascending colon and cecum, the surgeon is able to identify the base of the appendix.[2]
Destruction of the sacral spinal cord will eliminate parasympathetic outflow to the hindgut, pelvic organs, and perineum as well as somatic innervation to much of the pelvis and lower limbs. Because it stimulates gut motility and tone, loss of parasympathetic input will result in relaxation and inactivity of the teniæ coli in the descending colon.
