Which artery primarily supplies the leg region of the primary motor cortex?

• A. Middle Cerebral Artery
• B. Anterior Cerebral Artery
• C. Basilar Artery
• D. Posterior Cerebral Artery

Answer: (B)

The leg area of the primary motor cortex is located on the medial surface of the hemisphere (the paracentral lobule) and is supplied mainly by the anterior cerebral artery and its distal branches along the medial wall. This vascular supply explains why leg movements are most affected with ACA territory involvement. In contrast, the middle cerebral artery covers the lateral surface and governs movements of the face and arm, while the basilar and posterior cerebral arteries supply other regions such as the brainstem, cerebellum, and occipital/temporal lobes. Thus, the artery most responsible for the leg region is the anterior cerebral artery.