The primary motor cortex is associated with which Brodmann area?

The primary motor cortex is associated with which Brodmann area?

• A. BA 17
• B. BA 39
• C. BA 4
• D. BA 41

Answer: (C)

The main idea being tested is linking Brodmann areas to their functional roles in the cortex, identifying the region that initiates voluntary movement. The primary motor cortex sits in the precentral gyrus of the frontal lobe and corresponds to Brodmann area 4. This area is the origin of the corticospinal tract and is organized somatotopically into a motor map—the motor homunculus—reflecting which body parts are controlled by different parts of the cortex. That direct role in starting voluntary movement is what defines area 4. The other regions listed have different functions and locations: area 17 is the primary visual cortex in the occipital lobe; area 39 (angular gyrus) is involved in language, number processing, and higher-level integration in the parietal lobe; area 41 is the primary auditory cortex in the temporal lobe. Therefore, area 4 best matches the primary motor cortex.

The main idea being tested is linking Brodmann areas to their functional roles in the cortex, identifying the region that initiates voluntary movement. The primary motor cortex sits in the precentral gyrus of the frontal lobe and corresponds to Brodmann area 4. This area is the origin of the corticospinal tract and is organized somatotopically into a motor map—the motor homunculus—reflecting which body parts are controlled by different parts of the cortex. That direct role in starting voluntary movement is what defines area 4.

The other regions listed have different functions and locations: area 17 is the primary visual cortex in the occipital lobe; area 39 (angular gyrus) is involved in language, number processing, and higher-level integration in the parietal lobe; area 41 is the primary auditory cortex in the temporal lobe. Therefore, area 4 best matches the primary motor cortex.