sympathetic nervous system

Thân thiện

The sympathetic nervous system activates during a stressful event.

Definition

Noun: - A major division of the autonomic nervous system. It prepares the body for action, often in response to stress or perceived threats, by initiating physiological changes such as increasing heart rate, constricting blood vessels, and reducing digestive activity. It generally opposes the effects of the parasympathetic nervous system.

Usage

The term is used in biological, medical, and physiological contexts to describe the specific part of the nervous system responsible for the "fight-or-flight" response. - The sympathetic nervous system is activated during moments of intense fear or excitement. - Doctors explained that the patient's high blood pressure was linked to an overactive sympathetic nervous system.

Advanced Usage

• "Sympathetic activation": Refers to the process or state of the sympathetic nervous system becoming active.
  • Sympathetic activation causes a release of adrenaline into the bloodstream.
• "Sympathetic tone": Refers to the constant, baseline level of activity of the sympathetic nervous system.
  • Increased sympathetic tone can contribute to chronic hypertension.

Variants and Related Words

• Sympathetic (adjective): Pertaining to or acting on the sympathetic nervous system.
  • Sympathetic nerve fibers innervate the heart.
• Sympathetically (adverb): In a manner relating to the sympathetic nervous system.
  • The organ is innervated sympathetically.

Synonyms

• Thoracolumbar system (a technical synonym based on its anatomical origin).

Related Phrases and Concepts

• "Fight-or-flight response": The collective physiological reaction coordinated by the sympathetic nervous system.
• "Autonomic nervous system (ANS)": The overarching system controlling involuntary bodily functions, of which the sympathetic nervous system is a branch alongside the parasympathetic nervous system.

Học thuật

Noun

1. originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vessels