sympathetic nervous system

noun

: 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

Example Sentences

Recent Examples on the Web

What's actually happening is, my sympathetic nervous system has decided to reroute the path of my blood to my muscles. Jessica Leon, EW.com, 14 Nov. 2022

Cortisol is a hormone that increases activity in the sympathetic nervous system, which includes the heart, and its levels tend to peak first thing in the morning. Markham Heid, Time, 4 Nov. 2022

As a result, your sympathetic nervous system might kick in with shivering to warm you up and give you some energy. Julie Stewart, Men's Health, 29 June 2022

Overproduction of certain kinds of white blood cells that produce hormones and other factors that mimic or activate your body’s sympathetic nervous system to give you the sensation of chills. Julie Stewart, Men's Health, 29 June 2022

Deep breathing also calms the sympathetic nervous system and relieves stress. Hayden Carpenter, Outside Online, 20 May 2021

According to the Cleveland Clinic, stellate ganglion block (SGB) is an injection of medication into the stellate ganglion, a part of the sympathetic nervous system that is located in the neck, on either side of the voice box. Serena Coady, SELF, 15 Apr. 2022

During the day, the sympathetic nervous system regulates different functions that help the body prepare for activity and governs our body’s response to stress. Jennifer Leman, Popular Mechanics, 28 Mar. 2022

The autonomic nervous system, which regulates things like heart rate, pupil dilation, body temperature, and digestion, can be split into two categories: the sympathetic nervous system and the parasympathetic nervous system. Jennifer Leman, Popular Mechanics, 28 Mar. 2022

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Word History

First Known Use

1850, in the meaning defined above

Kids Definition

sympathetic nervous system

noun

: the part of the autonomic nervous system that is concerned especially with preparing the body to react to situations of stress or emergency, that controls expansion of the pupil of the eye and air passages, increases the heart rate, slows digestion, and narrows most blood vessels, and that is made up of nerve fibers that trigger the release of norepinephrine compare parasympathetic nervous system

Medical Definition

sympathetic nervous system

noun

: 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