network of neurons mostly within the brainstem that helps regulate attention and arousal levels (sleep and wakefulness, consciousness).
The widespread network of nerves throughout the brain that control how awake and alert or, conversely, how drowsy or asleep we are at any time.
rah-TIK-u-lar AK-tah-vay-ting SIS-tem (RAS) A diffuse network of cell bodies and nerve tracts that extends through the brain stem and into the thalamus; screens sensory input to the cerebrum. 627
Region in the brainstem tegmentum that, when stimulated, causes arousal; involved in modulating sleepÂwakefulness
the component of the reticular formation that is responsible for the sleep-wake cycle; it mediates various levels of alertness
The reticular activating system is the name given to part of the brain (the reticular formation and its connections) believed to be the center of arousal and motivation in animals (including humans). The activity of this system is crucial for maintaining the state of consciousness. It is situated at the core of the brain stem between the myelencephalon (medulla oblongata) and mesencephalon (midbrain).