saccus

Saccus is a Latin noun meaning a bag, sack, or pouch. In anatomical and biological terminology it is used as a root or component of compound terms to denote sac-like structures. It is generally not used as a stand-alone term in modern English, but appears in many historic and scientific names.

In human anatomy and related medical terminology, saccus appears in several well-known structures. The lacrimal sac, or saccus lacrimalis, collects tears from the surface of the eye and passes them into the nasolacrimal duct for drainage. The endolymphatic sac, or saccus endolymphaticus, is part of the inner ear’s endolymphatic system and is involved in regulating pressure and composition of the endolymph fluid.

In comparative anatomy and zoology, the root appears in other sac-like structures across taxa. For example, the saccus vasculosus refers to a highly vascularized sac associated with the brain in many fishes; its exact function is not fully settled and remains a subject of research and debate.

Etymology and usage: saccus derives from Latin for “bag” or “pouch.” While the term remains part of scholarly nomenclature, many modern descriptions prefer more general terms such as “sac” to describe similar structures in plain language.

See also: Lacrimal sac; Endolymphatic sac.