The taenia coli are three separate longitudinal ribbons of smooth muscle

Smooth muscle

Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...

 on the outside of the ascending, transverse, descending and sigmoid colon

Colon (anatomy)

The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...

s. They are visible, and can be seen just below the serosa or fibrosa.
They are the Mesocolic, Free and Omental Coli. The teniae coli contract lengthwise to produce the haustra

Haustra

The haustra of the colon are the small pouches caused by sacculation, which give the colon its segmented appearance. The taenia coli runs the length of the large intestine...

, the bulges in the colon.

The bands converge at the root of the vermiform appendix

Vermiform appendix

The appendix is a blind-ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouchlike structure of the colon...

 and the rectum.

These bands correspond to the outer layer of the muscularis externa

Muscularis externa

The muscular coat is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa membrane...

, in other portions of the digestive tract.

External links

- "Digestive System: Alimentary Canal: colon, taeniae coli" - "Intestines and Pancreas: Large Intestine"