DICTIONARY OF TERMS
COELOM

Pronunciation: see-lome

Etymology:

A coelom is a fluid-filled cavity that lies between the outer wall and the digestive tract that is bound by a specialized epithelial tissue called peritoneum.  In this condition, all organs in the coelom are connected to the body wall by mesenteries.

Different types of body plans in triploblastic animals. The Pseudocoelom is a persistent blastocoel with no connection between the gut and body wall.  The Acoelom is similar to the pseudocoelom, but the cavity is filled with parenchyma.  The Eucoelom (coelomate condition) has a body cavity that is derived secondarily during development with an internal cell layer called peritoneum and mesenteries connecting all organs in the coelom.  Image from:  http://www.nhc.ed.ac.uk/index.php?page=24.25.312.321.331

 

By Jack R. Holt.  Last revised: 02/01/2014