Which of the following supplies blood to the inferior and medial surfaces of the parietal lobe of the brain?

The posterior cerebral artery is the correct answer because it is primarily responsible for supplying blood to the inferior and medial surfaces of the parietal lobe, as well as parts of the occipital lobe and the lower portions of the temporal lobe. Specifically, this artery branches off from the basilar artery, which itself is formed by the union of the vertebral arteries and provides blood flow to the posterior aspect of the brain.

In contrast, the middle cerebral artery primarily supplies blood to the lateral aspects of the frontal, parietal, and temporal lobes, making it essential for motor and sensory functions of the upper body and face. The anterior cerebral artery focuses on supplying the medial surfaces of the frontal lobes and the superior medial parietal lobes, but not the inferior aspects of the parietal lobe. The basilar artery, while important as a major vessel supplying the posterior circulation of the brain, does not directly supply blood to specific lobes; rather, it gives rise to several branches, including the posterior cerebral arteries.

Therefore, understanding the vascular supply of the brain is crucial in both clinical and anatomical contexts, as it helps identify potential areas affected by strokes or other vascular disorders.