What do the vertebral arteries supply blood to?

The vertebral arteries primarily supply blood to the cervical part of the spinal cord and the brain. These paired arteries branch off from the subclavian arteries and ascend the neck through the foramina of the cervical vertebrae, ultimately uniting to form the basilar artery at the base of the skull.

Once they reach the brain, the vertebral arteries provide essential blood flow to various structures, particularly in the posterior circulation, including parts of the brainstem and cerebellum. The blood supplied by the vertebral arteries is crucial for maintaining the function of these regions, which are involved in vital processes such as coordination, balance, and autonomic functions.

In contrast, the other options listed pertain to different vascular supplies. The optic tract is typically supplied by the internal carotid arteries, while the thalamus and internal capsule receive their blood primarily from the branches of the internal carotid artery and posterior cerebral artery. Therefore, understanding the correct vascular territories is crucial for comprehending how various regions of the central nervous system are nourished.