A structure that includes parts of the hindbrain and midbrain and that is involved in sleep, wakefulness, pain perception, breathing, and muscle reflexes.

A long, narrow network of neurons that run through the medulla and the pons. Its job is to filter out some of the stimuli that are coming into the brain from the spinal cord, to relay the remainder of the signals to other areas of the brain, and to play a role in walking, eating, sexual activity, and sleeping.