Comparison of Body Cavities in Triploblastic Animals

These flashcards cover the vocabulary and definitions related to body cavities in triploblastic organisms, including coelom, hemocoel, and aceolomate.

Coelom

A body cavity that is entirely surrounded by tissues derived from the mesoderm.

Hemocoel

A body cavity located between tissues derived from the endoderm and mesoderm; formerly called pseudocoelom.

Aceolomate

Organisms that do not have a body cavity.

Triploblastic

Organisms that have three embryonic tissue layers: ectoderm, mesoderm, and endoderm.

Ectoderm

The outermost layer of embryonic tissue, which forms the outer body covering.

Mesoderm

The middle layer of embryonic tissue, which forms muscles and other structures.

Endoderm

The innermost layer of embryonic tissue, which lines the digestive tract.

Gastrovascular cavity

A digestive cavity that has branching structures and functions as both a digestive and circulatory system.

Nematode

A type of worm that has a hemocoel as its body cavity.

Planarian

A type of flatworm that is compact and lacks a body cavity.