összehúzódása

Összehúzódása is a Hungarian noun meaning the act or process of contracting or drawing together. It is formed from the verb összehúzódni (to contract, shrink, withdraw) with the possessive suffix -a, and it is used in different contexts to denote shortening, tightening, or reduction of size or activity. The term appears in physiology, physics, and economics, among other fields.

In physiology, összehúzódás usually refers to muscle contraction, the process by which muscle fibers generate force and shorten. The mechanism involves the sliding of actin and myosin filaments within sarcomeres, powered by ATP and regulated by calcium ions that enable cross-bridge cycling. The heart’s beat is described as a cycle of cardiac contractions (szívösszehúzódás) during systole, followed by relaxation.

In physics and materials science, összehúzódás describes contraction or shrinkage of substances under changing conditions, such as cooling. Materials may exhibit thermal contraction, quantified by the coefficient of thermal expansion and the changes in length or volume that accompany temperature changes.

In economics and everyday language, összehúzódás can denote a reduction in activity or size, such as an economic contraction, downsizing of an organization, or a tightened budget.