reticular formation, a small, thick cluster of neurons nestled within the brainstem, including the medulla that controls the level of consciousness and other vital functions of the body. The reticular formation constantly monitors the state of the body through connections with the sensory and motor tracts. Certain nerve cells in the formation regulate the flow of hydrochloric acid in the stomach. Other cells regulate swallowing, tongue movements, and movements of the face, eyes, and tongue.
