Parasympatholytic

A parasympatholytic element, also referred to as anticholinergics, reduces the activity of the parasympathetic nervous system. cite web |url=http://www.mercksource.com/pp/us/cns/cns_hl_dorlands_split.jsp?pg=/ppdocs/us/common/dorlands/dorland/six/000078651.htm |title=Dorlands Medical Dictionary:parasympatholytic |format= |work= |accessdate=] (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, such as organophosphates (often found in pesticides) act to block the parasympathetic nervous system as well.

"Parasympatholytic" and sympathomimetic are similar, but not identical. For example, both cause mydriasis, but parasympatholytics reduce accommodation (cycloplegia) while 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 which 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 suffering from asthma.

References

External links

* [http://www.salisbury.edu/healthsci/RESP/Classes/RLJoyner/Fall/AHPH544/4parasym.htm Overview at salisbury.edu]
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