Arteriole

Part of speech: noun

Definitions

1. A slender blood vessel that transitions between arteries and capillaries, facilitating blood distribution and pressure regulation
2. A diminutive vessel within the vascular system that links arteries to capillaries while controlling blood flow
3. A tiny blood vessel that branches out from an artery and directs blood into capillaries

Etymology: The Latin "artēria" that sits behind "arteriole" is itself a borrowing from Greek "artēria", and the Greeks had a surprising idea of what these vessels carried. Ancient anatomists assumed the arteries held air, which is why the name points to the windpipe-like tubes of the body rather than to blood. The Greek word is thought to derive from a root meaning to hang or to suspend, a guess that remains uncertain. "Arteriole" is the diminutive form, built by adding the Latin suffix "-ola" to "arteria", so it means a little artery. It reached English by way of French "artériole", which carried the same meaning across the Channel. The sense narrowed over the centuries: where the parent word covers the large, pressurised vessels leaving the heart, the diminutive names the smallest branches that feed the capillaries and regulate how much blood reaches each tissue.

Synonyms: small artery