The pons is a broad, bulging region of the brainstem that sits above the medulla and below the midbrain. It serves as a bridge for pathways connecting the cerebral cortex, cerebellum, and spinal cord, and it contains nuclei that help regulate sleep, breathing, and several cranial-nerve functions.

Fiber tracts ascending and descending through the pons carry sensory and motor information. Pontine nuclei relay signals from the cortex to the cerebellum, supporting the coordination of movement. Nuclei within the pons contribute to the control of facial expression, chewing, eye movements, and the transition between sleep stages. Damage to the pons can disrupt these functions and, in severe cases, produce states of profound paralysis with preserved awareness.

The pons is densely packed with critical pathways and nuclei in a relatively small volume. Even limited lesions can therefore have widespread effects. Its role in linking higher and lower levels of the nervous system makes it an essential node in the control of both movement and arousal.

Much of the traffic between the brain’s higher centers and the rest of the body passes through the pons.