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Parasympatholytic - Wikipedia (1)

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Parasympatholytic
A parasympatholytic agent is a substance or activity that reduces the activity of the
parasympathetic nervous system.[1][2] (The parasympathetic nervous system is often colloquially
described as the "Feed and Breed" or "Rest and Digest" portion of the autonomic nervous
system. The parasympathetic nervous system becomes strongly engaged during or after a meal
and during times when the body is at rest.)
The term parasympatholytic typically refers to the effect of a drug, although some poisons act to
block the parasympathetic nervous system as well. Most drugs with parasympatholytic
properties are anticholinergics.
"Parasympatholytic" and sympathomimetic agents have similar but not identical effects. For
example, both cause mydriasis, but parasympatholytics reduce accommodation (cycloplegia),
whereas sympathomimetics do not.
Clinical significance
Parasympatholytic drugs are sometimes used to treat slow heart rhythms (bradycardias or
bradydysrhythmias) caused by myocardial infarctions or other pathologies, as well as to treat
conditions that cause bronchioles in the lung to constrict, such as asthma. By blocking the
parasympathetic nervous system, parasympatholytic drugs can increase heart rate in patients
with bradycardic heart rhythms, and open up airways and reduce mucous production in patients
with asthma.
About
1. "Dorlands Medical Dictionary:parasympatholytic" (http://www.mercksource.com/pp/us/cns/cns_hl_dorla
nds_split.jsp?pg=/ppdocs/us/common/dorlands/dorland/six/000078651.htm)
.
2. Wilhelm, Helmut (2011). "Disorders of the pupil". Handbook of Clinical Neurology. Elsevier. pp. 427–466.
doi:10.1016/b978-0-444-52903-9.00022-4 (https://doi.org/10.1016%2Fb978-0-444-52903-9.00022-4)
ISSN 0072-9752 (https://www.worldcat.org/issn/0072-9752)
.
. "Drugs that stimulate the
parasympathetic nervous system are called parasympathomimetics or cholinergics. Drugs that inhibit the
parasympathetic system are called parasympatholytics or anticholinergics. Drugs that stimulate the
sympathetic nervous system are called sympathomimetics or adrenergics. Drugs that inhibit the
sympathetic system are called sympatholytics or antiadrenergics."
External links
Overview at salisbury.edu (http://www.salisbury.edu/healthsci/RESP/Classes/RLJoyner/Fall/A
HPH544/4parasym.htm)
Parasympatholytics (https://meshb.nlm.nih.gov/record/ui?name=Parasympatholytics)
at
the US National Library of Medicine Medical Subject Headings (MeSH)
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