Which two vessels supply blood to the brain?

The correct choice identifies the internal carotid and vertebral arteries as the primary vessels supplying blood to the brain. The internal carotid arteries are crucial because they deliver a significant portion of blood to the anterior circulation of the brain, including key areas such as the frontal, parietal, and temporal lobes. These arteries branch into the anterior and middle cerebral arteries, which are vital for providing adequate blood flow to critical brain regions.

The vertebral arteries, on the other hand, are important for supplying the posterior circulation of the brain. They merge to form the basilar artery, which supplies blood to the brainstem and cerebellum, areas essential for numerous functions including coordination, balance, and respiratory control.

This combination of blood supply ensures that both the anterior and posterior aspects of the brain receive the nutrients and oxygen necessary for proper function, highlighting the significance of the internal carotid and vertebral arteries in cerebral perfusion.