sympathetic nervous system


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 When our brains perceive threats, fear is communicated throughout the body via stress hormones and the sympathetic nervous system, or our fight-or-flight response. Kristen Rogers, CNN, "Quarantine fatigue: Why some of us have stopped being vigilant and how to overcome it," 8 June 2020 Research shows that physical touch calms our sympathetic nervous system, which regulates the amount of stress hormones our bodies produce. Popular Science, "New Zealand has eliminated COVID-19. Here’s how they’re keeping it that way.," 8 June 2020 Yoga reduces activity of the sympathetic nervous system, which controls the body's involuntary response to stressful situations, increasing heart rate and alertness and sending extra blood to the muscles, Sharma said. Kristen Rogers, CNN, "Struggling with migraines? This specific yoga routine can help, study says," 6 May 2020 Angiotensin converting enzyme 2 receptors, or ACE2 receptors for short, are a part of the sympathetic nervous system. Katherine Ellen Foley, Quartz, "The coronavirus’s survival mechanism is what makes it so dangerous," 24 Mar. 2020 But luckily, the sympathetic nervous system doesn’t waste time. Jade Wu Savvy Psychologist, Scientific American, "Why Negative Emotions Aren’t All Bad," 5 Nov. 2019 There’s a long discussion in the paper of why the sauna might have negative effects, including strain on the circulatory system, activation of the sympathetic nervous system, neurohormonal stress as indicated by cortisol release, and so on. Alex Hutchinson, Outside Online, "The Hidden Cost of the Post-Workout Sauna," 17 Jan. 2020 This happens because epidurals affects the sympathetic nervous system, a series of nerves that spread out from your spine to your body that help control several involuntary body functions, including blood flow. Samantha Lauriello,, "Epidural Side Effects and Risks, According to an Ob-Gyn," 12 Nov. 2019 This takes the brakes off the sympathetic nervous system, unleashing the body’s stress response, including the release of adrenaline, Karsenty says. Emily Underwood, Science | AAAS, "Hormone secreted by bones may help us escape danger," 12 Sep. 2019

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.

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First Known Use of sympathetic nervous system

1850, in the meaning defined above

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Time Traveler for sympathetic nervous system

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The first known use of sympathetic nervous system was in 1850

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Last Updated

16 Jun 2020

Cite this Entry

“Sympathetic nervous system.” Dictionary, Merriam-Webster, Accessed 8 Jul. 2020.

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More Definitions for sympathetic nervous system

sympathetic nervous system


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

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