|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
adrenoceptor
adrenoceptor (adrenoreceptor; adrenergic receptor) Any cell receptor that binds and is activated by the catecholamines adrenaline or noradrenaline. Adrenoceptors are therefore crucial in mediating the effects of catecholamines as neurotransmitters or hormones. There are two principal types of adrenoceptor, alpha (α) and beta (β), and various subtypes of each, with differing sensitivities to the catecholamines and to certain drugs. The alpha adrenoceptors fall into two main subtypes: α1-adrenoceptors, which mediate the contraction of smooth muscle and hence, for example, cause constriction of blood vessels due to contraction of their muscular walls; and α2-adrenoceptors, which occur, for example, in presynaptic neurons at certain nerve synapses, where they inhibit release of noradrenaline from the neuron. The beta adrenoceptors also have two main subtypes: β1-adrenoceptors, which stimulate cardiac muscle causing a faster and stronger heartbeat; and β2-adrenoceptors, which mediate relaxation of smooth muscle in blood vessels, bronchi, the uterus, bladder, and other organs. Activation of β2-adrenoceptors thus causes widening of the airways (bronchodilation) and blood vessels (vasodilation). See also beta blocker
|
|
|
Cite this article
"adrenoceptor." A Dictionary of Biology. 2004. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. "adrenoceptor." A Dictionary of Biology. 2004. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O6-adrenoceptor.html "adrenoceptor." A Dictionary of Biology. 2004. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-adrenoceptor.html |
|
adrenoceptor
adrenoceptor (ă-dree-noh-sep-ter) n. see adrenergic (receptor).
|
|
|
Cite this article
"adrenoceptor." A Dictionary of Nursing. 2008. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. "adrenoceptor." A Dictionary of Nursing. 2008. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O62-adrenoceptor.html "adrenoceptor." A Dictionary of Nursing. 2008. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-adrenoceptor.html |
|
Search over 100 encyclopedias and dictionaries:
HighBeam™ Research, Inc. © Copyright 2012. All rights reserved.
The Encyclopedia.com advertising network includes:
