sympathetic nervous system

noun

Definition of sympathetic nervous system

: the part of the autonomic nervous system that contains chiefly adrenergic fibers and tends to depress secretion, decrease the tone and contractility of smooth muscle, and increase heart rate — compare parasympathetic nervous system

Examples of sympathetic nervous system in a Sentence

Recent Examples on the Web Our autonomic nervous system has two branches: the sympathetic nervous system (or gas) and the parasympathetic nervous system (or brakes). Bryan Robinson, Forbes, "Why ‘Work-Life Balance’ Has Become A Career Dinosaur," 12 Mar. 2021 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system – which triggers the fight-or-flight response – and activates the parasympathetic system, which acts more like a brake on strong emotions. The Conversation, oregonlive, "Health psychologist says there are real, medicine-free ways to help your stress," 29 Dec. 2020 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system – which triggers the fight-or-flight response – and activates the parasympathetic system, which acts more like a brake on strong emotions. The Conversation, oregonlive, "Health psychologist says there are real, medicine-free ways to help your stress," 29 Dec. 2020 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system – which triggers the fight-or-flight response – and activates the parasympathetic system, which acts more like a brake on strong emotions. The Conversation, oregonlive, "Health psychologist says there are real, medicine-free ways to help your stress," 29 Dec. 2020 But a spinal cord injury essentially severs the connection between the reflexive neurons that sense blood pressure and the sympathetic nervous system that adjusts accordingly. Theresa Gaffney, STAT, "Scientists create a thermostat for blood pressure to help patients with spinal cord injuries," 27 Jan. 2021 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system – which triggers the fight-or-flight response – and activates the parasympathetic system, which acts more like a brake on strong emotions. The Conversation, oregonlive, "Health psychologist says there are real, medicine-free ways to help your stress," 29 Dec. 2020 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system – which triggers the fight-or-flight response – and activates the parasympathetic system, which acts more like a brake on strong emotions. The Conversation, oregonlive, "Health psychologist says there are real, medicine-free ways to help your stress," 29 Dec. 2020 Another is that the switch from negative to positive emotions quiets your sympathetic nervous system—which triggers the fight-or-flight response—and activates the parasympathetic system, which acts more like a brake on strong emotions. Popular Science, "Boost your mood with emotional brain training," 4 Jan. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sympathetic nervous system.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of sympathetic nervous system

1850, in the meaning defined above

Keep scrolling for more

Learn More about sympathetic nervous system

Time Traveler for sympathetic nervous system

Time Traveler

The first known use of sympathetic nervous system was in 1850

See more words from the same year

Statistics for sympathetic nervous system

Last Updated

25 Mar 2021

Cite this Entry

“Sympathetic nervous system.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sympathetic%20nervous%20system. Accessed 10 May. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

More Definitions for sympathetic nervous system

sympathetic nervous system

noun

Medical Definition of sympathetic nervous system

: the part of the autonomic nervous system that is concerned especially with preparing the body to react to situations of stress or emergency, that contains chiefly adrenergic fibers and tends to depress secretion, decrease the tone and contractility of smooth muscle, increase heart rate, and that consists essentially of preganglionic fibers arising in the thoracic and upper lumbar parts of the spinal cord and passing through delicate white rami communicantes to ganglia located in a pair of sympathetic chains situated one on each side of the spinal column or to more peripheral ganglia or ganglionated plexuses and postganglionic fibers passing typically through gray rami communicantes to spinal nerves with which they are distributed to various end organs

called also sympathetic system

— compare parasympathetic nervous system

More from Merriam-Webster on sympathetic nervous system

Britannica.com: Encyclopedia article about sympathetic nervous system

Comments on sympathetic nervous system

What made you want to look up sympathetic nervous system? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

Star Wars Words Quiz

  • cu jedi training
  • The bounty portion of bounty hunters (such as Boba Fett) comes from a Latin word meaning
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!