What does pseudocoelom mean?
A pseudocoelom is a fluid-filled body cavity that is not completely lined by mesoderm. It occurs in certain invertebrate groups, especially nematodes and rotifers, and is often called a false coelom. The distinction from a true coelom is anatomical: a true coelom is wholly lined by mesoderm, whereas a pseudocoelom has only a partial mesodermal lining and is typically bounded in part by endoderm or by mesenteries. In many animals, the cavity provides space for internal organs to move and, when fluid-filled, helps provide a hydrostatic skeleton. The term is primarily used in zoology, comparative anatomy, and developmental biology. Related adjectives include pseudocoelomate and pseudocoelomous, which describe animals or structures possessing this kind of cavity.
nounA body cavity in an animal that is not completely lined by mesoderm, such as in nematodes and rotifers. It is often called a false coelom because it differs developmentally and structurally from a true coelom.
- A body cavity that is not completely lined by mesoderm, found in certain invertebrate animals.
"The nematode has a pseudocoelom that functions as a hydrostatic skeleton and provides space for organ movement."
"In nematodes, the pseudocoelom contains fluid and acts as a hydrostatic skeleton."
"The presence of a pseudocoelom distinguishes many pseudocoelomate animals from those with a true coelom."
The standard plural of pseudocoelom is pseudocoeloms.
"Some nematodes possess pseudocoeloms that function as hydrostatic skeletons."
A pseudocoelom is a body cavity with an identity crisis: it looks like a coelom, but it is not fully lined by mesoderm.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does pseudocoelom come from?
The word combines the Greek-derived prefix pseudo-, meaning false, with coelom, from Greek koilōma, meaning a cavity or hollow space. The compound pseudocoelom was developed to distinguish a partially mesoderm-lined body cavity from a true coelom. Its relatives pseudocoelomate and pseudocoelomous were formed from the same elements.
Related word forms
How pseudocoelom is actually used
This is a specialized zoological and comparative-anatomy term. It is normally used in formal scientific writing, and related terms include pseudocoelomate and pseudocoelomous.
Easily confused with pseudocoelom
A coelom is a body cavity completely lined by mesoderm, whereas a pseudocoelom is only partially lined by mesoderm.