vasoconstrictor (redirected from Vasoconstrictors)

vasoconstrictor /vaso·con·stric·tor/ (-kon-strik´ter)

1. causing constriction of blood vessels.

2. a nerve or agent that does this.

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va·so·con·stric·tor (vz-kn-strktr)

n.

Something, such as a nerve or drug, that causes vasoconstriction.

adj.

Producing vasoconstriction.

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vasoconstrictor

[-kənstrik′tər]

Etymology: L, vas + constrigere

1  adj, pertaining to a process, condition, or substance that causes the constriction of blood vessels.

2  n, also called vasopressor. an agent that promotes vasoconstriction. Cold, fear, stress, and nicotine are common exogenous vasoconstrictors. Internally secreted epINEPHrine and norepinephrine cause blood vessels to contract by stimulating alpha-adrenergic receptors on the vascular smooth muscle. Other endogenous vasoconstrictors are angiotensin, which is formed in the blood through the action of renin, and antidiuretic hormone, which is secreted by the pituitary. Alpha-adrenergic sympathomimetic drugs also cause vasoconstriction, and several of these agents are used for this action in maintaining blood pressure during anesthesia and in treating pronounced hypotension resulting from hemorrhage, myocardial infarction, septicemia, sympathectomy, or drug reactions. Among these therapeutic agents are phenylephrine, metaraminol, and norepinephrine.

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vasoconstrictor (vāˈ·zō·kn·strikˑ·ter),

n a substance that narrows blood vessels by constricting the smooth muscle in the walls; increases blood pressure.

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vasoconstrictor (vā´zōknstrik´tur),

n (vasopressor), an agent that causes a rise in blood pressure by constricting the blood vessels. In local areas, it causes constriction of the arterioles and capillaries.

vasoconstrictor, adrenergic agents as,

n adrenaline-mimicking drugs that increase the duration of local anesthesia by constricting the blood vessels, thereby safely concentrating the anesthetic agent for an extended duration and reducing hemorrhage. Excessive amounts can cause systemic toxicity, especially in certain medical conditions or when combined with certain medications. Also used in gingival retraction cord impregnated with epinephrine. In dentistry, this includes epinephrine and levonordefrin.

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vasoconstrictor

1. causing constriction of the blood vessels.

2. a vasoconstrictive agent.

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vasoconstrictor agents

includes some prostaglandins, thromboxane A₂, leukotriene D₄, angiotensin II, vasopressin, neuropeptide Y, endothelin.

vasoconstrictor fibers

adrenergic nerve fibers in the walls of all blood vessels except capillaries.

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vasoconstrictor

A vasoactive agent that constricts blood vessels–eg, epinephrine, norepinephrine, which is produced endogenously to compensate for hypotension and maintain vascular tone in hemorrhagic and other forms of shock. Cf Vasodilator.