Which part of the brainstem coordinates movements and helps with balance?

The part of the brainstem that coordinates movements and helps with balance is the pons. The pons serves several important functions, including relaying signals between various parts of the brain, particularly between the cerebellum and the cerebrum. It plays a crucial role in regulating movements and posture, thereby contributing to balance. The pons also helps integrate motor commands coming from the cerebral cortex with feedback from the body, which is vital for smooth and coordinated movements.

While the medulla is important for autonomic functions such as heartbeat and breathing, and the midbrain is involved in functions such as vision and hearing, neither of these structures is primarily responsible for coordinating balance or movement in the same way that the pons does. The cerebellum, while crucial for balance and motor coordination, is not part of the brainstem; rather, it is located just above the brainstem and works in conjunction with it. Therefore, the roles of the pons in coordinating movements and aiding in balance make it the correct choice in this context.