Supistaminen

Supistaminen is a Finnish noun that denotes the act of tightening, narrowing, or contracting. It is used both in everyday speech and in technical contexts to describe processes in which size, diameter, or volume decreases. The term is derived from the verbs supistaa (to tighten or compress) and supistua (to contract or constrict reflexively).

In physiology, supistaminen refers to the contraction of muscles, where fibers shorten due to cross-bridge cycling powered by calcium ions and ATP. It also describes vasoconstriction, the narrowing of blood vessels, which is controlled by the autonomic nervous system and hormones. Vasoconstriction alters blood flow and pressure by reducing the lumen of vessels.

Outside biology, the word can describe mechanical tightening or compression of materials, seals, ducts, or other structures, as when a clamp or squeeze reduces a component's dimensions.

In medical or scientific writing, supistaminen conveys both muscular contraction and constriction of luminal structures, with context clarifying the precise meaning.