Diverticulum

In medicine or biology, a diverticulum is an outpouching of a hollow (or a fluid-filled) structure in the body.

[1] Depending upon which layers of the structure are involved, diverticula are described as being either true or false.

[2] In medicine, the term usually implies the structure is not normally present, but in embryology, the term is used for some normal structures arising from others, as for instance the thyroid diverticulum, which arises from the tongue.

[3] The word comes from Latin dīverticulum, "bypath" or "byway".

Diverticula are described as being true or false depending upon the layers involved: Most of these pathological types of diverticula are capable of harboring an enterolith.

The 3 classifications of esophageal diverticula. 1-Pharyngeal (Zenker's) 2-Midesophageal 3-Epiphrenic
Histopathology of the gallbladder, showing a false diverticulum (larger than a Rokitansky–Aschoff sinus). It is not true, as the muscularis layer is essentially absent over the diverticulum rather than bulging outward.