The vertebral arteries are among the major arteries of the neck. Part of the vertebrobasilar system, these arteries are responsible for supplying blood to the brain stem portion of the human brain, which helps control basic functions such as breathing, heart rate, and sleeping.
The vertebral artery can be divided into four parts. The first part runs between the internal jugular vein and seventh cervical vertebra. The second part is situated in front of the trunks of the cervical nerves and runs vertically as far as the transverse process of the axis — which is a point of bone that sticks out diagonally from the axis, the second vertebra from the top of the spine. The third part originates from the C2 foramen transversarium (a hole in the vertebra near the transverse process). The fourth part pierces the dura mater (a layer of membrane that protects the brain) and runs down to the medulla oblongata (a portion of the brain stem that is the primary control center for heart rate and breathing).
Both vertebral arteries, the one on the left and the other on the right, rise up from the subclavian arteries on a path parallel to the carotid artery. Inside the skull, the two vertebral arteries merge to form the basilar artery, which is among the arteries supplying blood to the brain.
Amongst various vertebral artery diseases, the most common one is cerebrovascular insufficiency, which is caused by a narrowing of one or both of the arteries, and can ultimately lead to a stroke.