reticular activating system
(Science: physiology) A physiological term denoting that part of the brainstem reticular formation that plays a central role in the organism’s bodily and behavorial alertness.
It extends as a diffusely organised neural apparatus through the central region of the brainstem into the subthalamus and the intralaminar nuclei of the thalamus; by its ascending connections it affects the function of the cerebral cortex in the sense of behavioural responsiveness; its descending (reticulospinal) connections transmit its activating influence upon bodily posture and reflex mechanisms (e.g., muscle tonus), in part by way of the gamma motor neurons.
See: reticular formation.
Synonym: non-specific system.
Dictionary > Reticular activating system
