Teniae

Teniae, or taeniae, are narrow, ribbon-like bands of tissue that run along or partition a structure. The term comes from Latin taenia, meaning ribbon or band. The best-known teniae are the taeniae coli, three longitudinal bands of smooth muscle located on the surface of the large intestine. These bands are named according to their relation to adjacent structures: taenia mesocolica near the mesentery, taenia omentalis near the omentum, and taenia libera opposite the mesenteric attachment. The taeniae coli converge at the base of the appendix. Contraction of the taeniae coli shortens the colon and helps produce haustral folds, segmenting the colon into sacs.

Outside the colon, the term taenia or teniae is used less regularly to describe similar ribbon-like bands in other parts of the body; in neuroanatomy and other areas, the word denotes narrow bands or ridges associated with specific regions or fibers. However, such uses are less standardized and can vary by source. In clinical anatomy, recognizing the taeniae coli is important for identifying the colon's boundaries during dissection, imaging, or surgical procedures. Abnormalities in the arrangement or integrity of the taeniae can affect colonic motility or the appearance of the colon on imaging.