Ventricle

Definition

A muscular chamber of a circulatory or digestive system that actively pumps or propels fluid contents; in arthropods, typically denotes the contractile heart chamber(s) or the thick-walled midgut region (ventriculus) where enzymatic digestion and absorption occur.

Etymology

Latin ventriculus, diminutive of venter (belly, stomach)

Example

In insects with a tubular heart, each segmental dilation functions as a contractile ventricle that drives hemolymph anteriorly through the aorta; in spiders, the ventricle of the sucking stomach generates negative pressure to draw liquefied prey into the gut.

Synonyms

• ventriculus (digestive context)

Related Terms

• Heart
• aorta
• ostium
• Hemolymph
• Midgut
• peristalsis
• sucking stomach

Usage Notes

Context determines meaning: cardiovascular versus digestive. In insect morphology, 'ventricle' for the heart is falling out of favor in favor of 'chamber' or simply 'heart segment,' while 'ventriculus' remains standard for the midgut. Arachnologists distinguish the cardiac ventricle (heart) from the gastric ventricle (sucking stomach). Not to be confused with 'ventral' (positional) or 'ventricose' (swollen).