Acinus

Part of speech: noun

Pronunciation: /ˈæsɪnəs/

Definitions

1. A diminutive, spherical formation located in particular glands that is essential for the secretion of various substances, acting as a key component in organs like the pancreas or salivary glands
2. A tiny, rounded cluster of cells within certain glandular tissues that generates secretions, forming a vital part of various body organs' functions
3. A small sac-like structure found in specific glands that plays a crucial role in secretion processes, contributing to the overall function of organs such as the pancreas and salivary glands

Etymology: The anatomical sense of this word began as a plain Latin word for a grape. "Acinus" meant "grape" or "grape-stone" in classical Latin, and it was taken into English without any change in form. Its jump from fruit to gland came through a visual comparison: when examined under a microscope, the cells of certain glands were seen to cluster in rounded groups that looked like bunches of tiny berries. The name therefore describes shape rather than function. Anatomists reached for a fruit image because the tiny gland units, the acini of the pancreas and salivary glands, appeared as small, grape-like clusters. Its everyday meaning of "grape" was not lost, but the medical sense now dominates, and the word is rarely used outside histology and pathology.