Based on the Random House Dictionary, © Random House, Inc. 2012.
Cite This Source
:10
:09
:08
:07
:06
:05
:04
:03
:02
:01
| Symbol: Tc; atomic weight: 99; atomic number: 43 |
| Symbol: Ti; atomic weight: 47.90; atomic number: 22 |
- Elements of space opera, Straubesque horror and adrenaline-laced action make this a demanding, rewarding read.
- Sometimes the burst of adrenaline you get the night before the deadline is enough to propel you to a successful finish.
- Human mind networks requires at least 3 kinds of neurotransmitters; adrenaline, serotonin and dopamine.
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
adrenaline
Cite This Source
adrenaline a·dren·a·line (ə-drěn'ə-lĭn)
n.
See epinephrine.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
adrenaline  (ə-drěn'ə-lĭn) Pronunciation Key
See epinephrine. |
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
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.”
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
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.
Learn more about adrenaline with a free trial on Britannica.com.
Cite This Source