Wiktionary
n. (context neuroanatomy English) The part of the autonomic nervous system that under stress raises blood pressure and heart rate, constricts blood vessels and dilates the pupils.
WordNet
n. originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vessels
Wikipedia
The sympathetic nervous system is one of the two main divisions of the autonomic nervous system, the other being the parasympathetic nervous system. The autonomic nervous system functions to regulate the body's unconscious actions. The sympathetic nervous system's primary process is to stimulate the body's fight-or-flight response. It is, however, constantly active at a basic level to maintain homeostasis. The sympathetic nervous system is described as being complementary to the parasympathetic nervous system which stimulates the body to "rest-and-digest" or "Feed and breed".
Usage examples of "sympathetic nervous system".
Unlike the other cranial nerves, which are concerned with the special senses or distributed to the skin and muscles of the head and neck, the vagus, as its name implies, strays downward into the chest and abdomen supplying branches to the throat, lungs, heart and stomach and forms an important connecting link between the brain and the sympathetic nervous system.
It stimulates the central nervous system by potentiating the effects of norepinephrine, a neurohormone which activates parts of the sympathetic nervous system.
Link it with the sympathetic nervous system that controls automatic respiration and heart beat.
McNulty to reconnect him, but the doctor had regretfully replied that Peter did not have the sympathetic nervous system to control voluntary actions, no matter how clever he had been at counterfeiting movement in his limbs.
The extreme level of his concentration had put him in partial control of his own sympathetic nervous system, another device of yogis and fakirs, and he had, unknowingly, gained some control over his body's involuntary functions.
A surprisingly wide range of phenomena: precognition, telekinesis, mental domination, bursts of superhuman strength, temporary control over the sympathetic nervous system.
At the same tune, it excited that part of the sympathetic nervous system which controlled the capillaries of the skin, thereby contracting them and lessening time blood-flow through them.
However, the term is hardly more justified than if it were applied to the human sympathetic nervous system .
However, the term is hardly more justified than if it were applied to the human sympathetic nervous system .