Reaction, vasovagal
A reflex of the involuntary nervous system called the vasovagal reaction. The vasovagal reaction leads the heart to slow down (bradycardia) and, at the same time, it effects the nerves to the blood vessels in the legs to permit those vessels to dilate (widen). The result is that the heart puts out less blood, the blood pressure drops, and what blood is circulating tends to go into the legs rather than to the head. The brain is deprived of oxygen and the fainting episode occurs. This sequence of events may lead to a temporary loss of consciousness in a particular kind of situation. (Syncope is temporary loss of consciousness or, in plain English, fainting). The situations that trigger this reaction are diverse and include having blood drawn, straining while urinating or defecating or coughing. The reaction also can be due to the emotional stress of fear or pain. Under these conditions, people often become pale and feel nauseated, sweaty, and weak just before they lose consciousness. The vasovagal reaction is also called a vasovagal attack. The resultant fainting is synonymous with situational syncope, vasovagal syncope, vasodepressor syncope, and Gower syndrome which is named for Sir William Richard Gower (1845-1915), a famous English neurologist whose name is also associated with a sign, a solution, another syndrome, and a tract in the central nervous system.

Medical dictionary. 2011.

Look at other dictionaries:

  • Vasovagal syncope — The temporary loss of consciousness in a particular kind of situation. (Syncope is temporary loss of consciousness or, in plain English, fainting). The situations that trigger this reaction are diverse and include having blood drawn, straining… …   Medical dictionary

  • Vasovagal reaction — A reflex of the involuntary nervous system called the vasovagal reaction. The vasovagal reaction leads the heart to slow down (bradycardia) and, at the same time, it effects the nerves to the blood vessels in the legs to permit those vessels to… …   Medical dictionary

  • Vasovagal attack — A reflex of the involuntary nervous system called the vasovagal reaction that leads the heart to slow down (bradycardia) and, at the same time, it affects the nerves to the blood vessels in the legs permitting those vessels to dilate (widen). The …   Medical dictionary

  • vasovagal — Relating to the action of the vagus nerve upon the blood vessel s. * * * va·so·va·gal .vā zō vā gəl adj of, relating to, or involving both vascular and vagal factors <a vasovagal reaction> * * * adj. relating to the action of impulses in… …   Medical dictionary

  • Syncope, vasovagal — The temporary loss of consciousness in a particular kind of situation. (Syncope is temporary loss of consciousness or, in plain English, fainting). The situations that trigger this reaction are diverse and include having blood drawn, straining… …   Medical dictionary

  • Attack, vasovagal — A reflex of the involuntary nervous system called the vasovagal reaction that leads the heart to slow down (bradycardia) and, at the same time, it affects the nerves to the blood vessels in the legs permitting those vessels to dilate (widen). The …   Medical dictionary

  • Local anesthesia — Intervention MeSH D000772 Local anesthesia is any technique to induce the absence of sensation in part of the body,[1] generally fo …   Wikipedia

  • Vasodepressor syncope — The temporary loss of consciousness in a particular kind of situation. (Syncope is temporary loss of consciousness or, in plain English, fainting). The situations that trigger this reaction are diverse and include having blood drawn, straining… …   Medical dictionary

  • Trypanophobia — is the extreme fear of medical procedures involving injections or hypodermic needles. It is occasionally referred to as aichmophobia, belonephobia, or enetophobia, names that are technically incorrect because they simply denote a “fear of… …   Wikipedia

  • Coughing syncope — The temporary loss of consciousness upon coughing. Syncope is the temporary loss of consciousness or, in plain English, fainting. The situations that trigger this reaction are diverse and include having blood drawn, straining while urinating… …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”