Cloaca is a term used in anatomy to describe the rear orifice that serves as the only opening for the digestive, reproductive, and urinary tracts of many vertebrate animals. In females, cloaca is also an anorectal malformation that affects the rectum and urogenital tract. Here are some key points about cloaca:
- In animals, mating through the cloaca is called cloacal copulation and cloacal kissing.
- The cloacal region is often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, marsupials, amphibians, and monotremes.
- In birds, the cloaca may also be referred to as the vent.
- In fish, a true cloaca is present only in elasmobranchs (sharks and rays) and lobe-finned fishes.
- In mammals, the cloaca is the enlarged terminal part of the posterior embryonic digestive tract that gives rise to the rectum, upper anal canal, and urogenital sinus.
The term "cloaca" is derived from the Latin verb "cluo," which means "I cleanse," and the noun "cloaca," which means "sewer".
