vasoconstriction

views updated Jun 27 2018

vas·o·con·stric·tion / ˌvāzōkənˈstrikshən; ˌvasō-/ • n. the constriction of blood vessels, which increases blood pressure.DERIVATIVES: vas·o·con·stric·tive / -ˈstriktiv/ adj.vas·o·con·stric·tor / -ˈstriktər/ n.

The Oxford Pocket Dictionary of Current English

vasoconstrictor

views updated May 23 2018

vasoconstrictor (vay-zoh-kŏn-strik-ter) n. an agent that causes narrowing of the blood vessels and therefore a decrease in blood flow. Vasoconstrictors are alpha agonists (see sympathomimetic), used to raise the blood pressure in disorders of the circulation, shock, or severe bleeding and to maintain blood pressure during surgery (see ephedrine, metaraminol, phenylephrine). Some (e.g. ephedrine, xylometazoline) are used to treat nasal congestion.

A Dictionary of Nursing

vasoconstriction

views updated May 29 2018

vasoconstriction The reduction in the internal diameter of blood vessels, especially arterioles or capillaries. The constriction of arterioles is mediated by the action of nerves on the smooth muscle fibres of the arteriole walls and results in an increase in blood pressure.

A Dictionary of Biology

vasoconstrictor

views updated May 23 2018

vasoconstrictor Any substance that causes constriction of blood vessels and, therefore, decreased blood flow. Examples include noradrenaline, angiotensin, and the hormone vasopressin (also known as anti-diuretic hormone).

World Encyclopedia