Which region contains the primary motor cortex for face, trunk, and arms?

• A. Parietal
• B. Frontal
• C. Temporal
• D. Occipital

Answer: (B)

Movement is organized in the brain with a map on the primary motor cortex, which sits in the frontal lobe, specifically along the precentral gyrus. This region is responsible for initiating voluntary movement, and its somatotopic map places the face, trunk, and arms on the lateral part of the precentral gyrus. That’s why movements of those parts are controlled here. The parietal lobe houses the primary somatosensory cortex, the temporal lobe handles hearing and memory, and the occipital lobe is for vision, so they don’t contain the primary motor cortex. In short, the frontal region is where the primary motor cortex for face, trunk, and arms resides.