Reticular Activating System

Synonyms

Reticular formation

Definition

The reticular activating system (RAS) denotes that part of the brainstem reticular formation that performs a crucial role in maintaining behavioral arousal, consciousness, and motivation.

Current Knowledge

The reticular activating system (RAS) denotes that part of the brainstem reticular formation that performs a crucial role in maintaining behavioral arousal, consciousness, and motivation. The RAS receives a wide range of inputs and projects as a diffusely organized neural complex extending from the core of the medulla oblongata through the subthalamus and thalamus. These cell groups send their axons to broad areas of the cerebral cortex with most terminating in the frontal lobe where they alert or activate the cerebral cortex as a whole. Once alerted, the conscious/perceptive part of the brain takes over, recognizes the source of the arousal, and addresses the problem. The reticular formation also gives rise to descending axons which pass to...