vasoconstrictor
Học thuậtThân thiện
Definition
Noun: 1. A substance that causes the narrowing of blood vessels: A vasoconstrictor is any agent, natural or synthetic, that causes the constriction (tightening) of blood vessels, particularly the small arteries and arterioles. This action increases blood pressure by reducing the space through which blood can flow.
Usage Examples
- Noun:
- Nicotine is a powerful vasoconstrictor, which is why smoking can lead to high blood pressure.
- The doctor administered a vasoconstrictor to control the bleeding during the minor surgical procedure.
- Cold temperatures act as a vasoconstrictor, causing blood vessels in the skin to narrow to conserve body heat.
Advanced Usage
- Physiological Role: Vasoconstrictors are part of the body's natural regulatory systems. For example, the hormone norepinephrine is released during stress to increase blood flow to muscles.
- Clinical Use: Vasoconstrictors like phenylephrine are often added to local anesthetics in dentistry to prolong their effect by keeping the drug localized. They are also used in emergency medicine to treat severe hypotension (very low blood pressure).
Variants and Related Words
- Vasoconstriction (n): The process or result of blood vessels narrowing.
- The vasoconstriction of peripheral vessels helps to maintain core body temperature.
- Vasoconstrictive (adj): Having the property of causing vasoconstriction.
- The drug has a strong vasoconstrictive effect.
Synonyms
- Pressor agent: A substance that raises blood pressure.
- Constrictor (in a medical/physiological context): An agent that causes constriction.
Antonyms
- Vasodilator (n): Any agent that causes the widening of blood vessels, which decreases blood pressure.
- Nitroglycerin is a vasodilator used to treat angina.
Noun
- any agent that causes a narrowing of an opening of a blood vessel: cold or stress or nicotine or epinephrine or norepinephrine or angiotensin or vasopressin or certain drugs; maintains or increases blood pressure