Fibrillae

Part of speech: noun

Definitions

1. Microscopic threads commonly occur in living tissues, where these fine structures help build and support muscle and connective tissue, and clusters of these minuscule strands allow tissues to contract and maintain their integrity
2. A set of very slender filaments that play vital roles in the formation and support of biological tissues, these tiny components are essential for the stability and contraction of muscles and other structures
3. Extremely small fibrous strands found in cells that contribute to the structural framework and aid in muscle function

Etymology: "Fibrillae" is the plural of "fibrilla", a Latin diminutive of "fibra", meaning "fibre" or "filament". The Latin suffix "-illa" makes a small version of the original, so a fibrilla is literally a little fibre. English took the word directly from Latin, and its close relative "fibril" arrived by a different path, giving two forms of one idea. The Latin ending is what does the work here. Many English words in "-il" or "-illa" come from Latin diminutives, which were used for anything small, from threads to tiny creatures, so the sense of "very fine thread" is built into the ending. Biologists and anatomists then applied the form to the microscopic threads they saw in tissue and muscle.