a⋅dren⋅a⋅line
[uh-dren-l-in, -een] 
l
ep⋅i⋅neph⋅rine
[ep-uh-nef-rin, -reen] | 1. | Biochemistry. a hormone secreted by the adrenal medulla upon stimulation by the central nervous system in response to stress, as anger or fear, and acting to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism. |
| 2. | Pharmacology. a commercial form of this substance, extracted from the adrenal glands of sheep and cattle, or synthesized: used chiefly as a heart stimulant, to constrict the blood vessels, and to relax the bronchi in asthma. |
Based on the Random House Dictionary, © Random House, Inc. 2009.
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| a·dren·a·line (ə-drěn'ə-lĭn) n. See epinephrine. |
| ep·i·neph·rine also ep·i·neph·rin (ěp'ə-něf'rĭn) n.
[epi- + nephr(o)- + -ine2.] |
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Adrenaline
Ad*re"nal*ine\, n. Also Adrenalin \Ad*re"nal*in\ (Physiol. Chem.) A crystalline substance, C9H13O3N, obtained from suprarenal extract, of which it is regarded as the active principle. It is used in medicine as a stimulant and hemostatic.Cite This Source
adrenaline [(uh-dren-l-in)]
A hormone secreted by the adrenal glands that helps the body meet physical or emotional stress (see endocrine system).
Note: Adrenaline plays a very large role in the fight or flight reaction, which refers to the various processes that occur within the body when it is confronted with some form of mental or physical stress.
Note: Figuratively, the term adrenaline is used in speaking of a high state of excitement: “When the race began, the adrenaline really started pumping.”
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Main Entry: adren·a·line
Pronunciation: &-'dren-&l-&n
Function: noun
:
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adrenaline a·dren·a·line (ə-drěn'ə-lĭn)
n.
See epinephrine.
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| adrenaline (ə-drěn'ə-lĭn) Pronunciation Key
See epinephrine. |
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adrenaline
two separate but related hormones secreted by the medulla of the adrenal glands. They are also produced at the ends of sympathetic nerve fibres, where they serve as chemical mediators for conveying the nerve impulses to effector organs. Chemically, the two compounds differ only slightly; and they exert similar pharmacological actions, which resemble the effects of stimulation of the sympathetic nervous system. They are, therefore, classified as sympathomimetic agents. The active secretion of the adrenal medulla contains approximately 80 percent epinephrine and 20 percent norepinephrine; but this proportion is reversed in the sympathetic nerves, which contain predominantly norepinephrine.
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