pons

Meaning: The pons (Latin for "bridge") is part of the hindbrain and the brainstem, between the medulla below and the midbrain above, in front of the cerebellum. It relays signals between the cerebrum and cerebellum, supporting coordinated movement. It also helps regulate sleep and arousal, including REM sleep, and works with the medulla in setting the rhythm of breathing.

On the MCAT: Expect classification or matching. Know that the hindbrain holds the medulla, pons, and cerebellum, and that the brainstem is the midbrain, pons, and medulla. A passage on sleep stages or a lesion may ask which function changes; link the pons to REM sleep, arousal, and relaying motor information to the cerebellum.

Common confusion: Students swap the pons with the medulla or the cerebellum. The medulla, just below the pons, runs vital autonomic reflexes such as heart rate, blood pressure, and breathing. The cerebellum sits behind the pons and fine-tunes balance and coordination; it is in the hindbrain but is not part of the brainstem.