<prompt> All of the following are true about reticular activating system exceptInvolved in arousalPolysynaptic pathwayReceives collateral from sensory pathwayDoesnot produce EEG aleing response  <response>: A high frequency stimulation of the midbrain reticular formation the RAS produces the EEG aleing response and arouses a sleeping animal. Reticular activating system RAS The RAS is a complex polysynaptic pathway arising from the brainstem reticular formation and hypothalamus with projections to the intralaminar and reticular nuclei of the thalamus which, in turn, project diffusely and nonspecifically to wide regions of the coex including the frontal, parietal, temporal, and occipital coices. Collaterals funnel into it from the long ascending sensory tracts, the trigeminal, auditory, visual , and olfactory systems. The reticular formation plays an impoant role in determining the level of arousal; thus, it is called the ascending activating systemARAS. Ref: Ganongs Review of Medical Physiology 25th edition Pgno: 271, 278 