Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.


, pl.


(pă-raf'i-sis, -sēz),
A median organ developing from the roofplate of the diencephalon in certain lower vertebrates. Present in the human embryo and fetus for a short time.
Synonym(s): paraphysial body
[G. an offshoot]


n. pl. paraphy·ses (-sēz′)
One of the erect sterile filaments often occurring among the reproductive organs of certain fungi, algae, and mosses.


(pă-răf′ĭ-sĭs) [Gr., offshoot]
The vestigial structure that originates from the roof plate of the telencephalon. Presumably the colloid cyst of the third ventricle arises from it. It is also a midline organ that develops from the roof plate of the diencephalon of some lower vertebrates.