Which structure is the 'little brain' at the rear of the brainstem, coordinating movement and balance?

• A. Cerebellum
• B. Cerebrum
• C. Brainstem
• D. Thalamus

Answer: (A)

The cerebellum coordinates movement and balance, earning its nickname the “little brain.” It sits at the rear of the brainstem and doesn’t start movements, but fine-tunes them. It takes in information about body position and head movement from the spinal cord and inner ear, compares that with the intended movements coming from the cerebral cortex, and then rapidly adjusts the timing and force of muscle activity to produce smooth, coordinated actions and stable posture. It also supports motor learning, adapting how we move as we practice and errors are detected.

In contrast, the cerebrum handles conscious thought, planning, and voluntary actions; the brainstem links the brain to the spinal cord and manages basic life functions and essential relay of information; the thalamus serves mainly as a relay station for sensory and motor signals to the cortex.