What it means
One of the two branches of the autonomic nervous systemaw-tuh-NOM-ik NUR-vus SIS-tumThe part of the nervous system that controls body functions without conscious thought, such as heart rate, breathing and digestion.auto- selfnom/o law, control-ic relating toFull entry . Using norepinephrinenor-ep-ih-NEF-rinA hormone and nerve messenger that narrows blood vessels and raises blood pressure, also given as an IV drug.Full entry and epinephrineep-ih-NEF-rinA hormone and drug, also called adrenaline, that raises heart rate and blood pressure and opens the airways.Full entry , it speeds the heart, raises blood pressure, opens the airways, widens the pupils, releases glucose for energy and slows digestion and bladder emptying. The parasympathetic nervous system has the opposite, calming effects ("rest and digest").
For the nurse
Drugs that mimic it (adrenergic agonistad-ruh-NER-jik AG-uh-nistA drug that acts like epinephrine or norepinephrine on the body's adrenergic receptors.adren/o adrenal gland-ergic working byagonist a drug that activates a receptorFull entry ) or block it (beta blockers, alpha blockers) change heart rate and blood pressure. Pain and anxiety also switch it on, raising pulse and blood pressure.
Remember it
Sympathetic is "fight or flight"; parasympathetic is "rest and digest".
At a glance
| Abbreviations | SNS (ambiguous on its own) |
|---|---|
| Spanish | sistema nervioso simpático |
| Also written | sympathetic nervous systems |
Related terms
autonomic nervous system
The part of the nervous system that controls body functions without conscious thought, such as heart rate, breathing and digestion.
norepinephrine
A hormone and nerve messenger that narrows blood vessels and raises blood pressure, also given as an IV drug.
autonomic
Working on its own, without conscious control; used for the nerves that run the organs.
adrenergic agonist
A drug that acts like epinephrine or norepinephrine on the body's adrenergic receptors.