ventriculus

Ventriculus is a Latin term meaning little belly and is used in anatomy to denote hollow organs or cavities in various parts of the body. In modern English anatomical usage, the corresponding term ventricle is more common for heart and brain cavities, but ventriculus appears in certain fields and in older or more specialized texts.

In vertebrate anatomy, ventriculus frequently refers to the stomach, particularly in veterinary contexts. In birds, the ventriculus (often called the gizzard) is a muscular chamber specialized for grinding ingested material, sometimes with the aid of ingested stones. In other animals the ventriculus may denote the glandular or abdominal stomach portion, depending on the species and anatomical tradition.

In neuroanatomy, ventriculus can denote the cavities within the brain that contain cerebrospinal fluid. The main brain cavities are the lateral ventriculi (ventriculi laterales), the third ventricle (ventriculus tertius), and the fourth ventricle (ventriculus quartus). The term is encountered in some texts as ventriculus cerebri or simply ventriculus, though modern usage often favors ventricle.

In entomology and other invertebrate anatomy, ventriculus is used to describe the midgut section of the alimentary canal, situated after the foregut structures such as the crop and proventriculus. This midgut region is a primary site of digestion and nutrient absorption in many insects.

Terminology varies by field and region, and the term ventriculus is less common in contemporary general human anatomy, where ventricle forms the preferred term for heart and brain cavities.