The vertebral artery is a major blood vessel that supplies oxygen-rich blood to the brain and spinal cord. It originates from the subclavian artery and travels upward through the cervical vertebrae in the neck. There are two vertebral arteries, one on each side of the body, and they join together to form the basilar artery at the base of the brain. These arteries play a crucial role in the vertebrobasilar circulation, which is essential for brain function. They provide blood to important areas, including the brainstem and cerebellum, helping to maintain vital functions such as balance, coordination, and consciousness.