Polyp

In zoology, a polyp is one of the two types of individuals found in many species of coelenterates[?]. The two are the polyp or hydroid and the medusa. Polyps are approximately cylindrical, elongated on the axis of the body. One end is usually attached and the other bears the mouth, surrounded by a circlet of tentacles[?]. The wall is relatively thin, due to the thinness of the mesogloea[?]. In the class Hydrozoa[?], the polyps are often very simple, like the common little freshwater species of the genus Hydra. Actinozoan[?] polyps, including the corals and sea anenomes[?], are much more complex due to the development of a tubular stomodaeum[?] leading inward from the mouth and a series of radial partitions called mesenteries. Many of the mesenteries project into the enteric cavity but some extend from the body wall to the central stomodaeum.

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In medicine, a polyp is a smooth-coated tumor projecting from a mucous membrane. It is attached to the surface by a narrow elongated pedicle[?]. Polyps are commonly found in the nose, bladder, rectum, and large intestine. They may also occur elsewhere in the body.