The vertebral artery refers to a branch of the subclavian artery. It is also known as the vertebral artery.
What is the vertebral artery?
The vertebral artery represents a branch of the subclavian (subclavian) artery. The blood vessel also goes by the names vertebral artery or vertebral artery and reaches a diameter of between 3 and 5 millimeters. Like most other arteries in the human body, the vertebral artery comes in pairs. Thus, one artery occurs on the right side of the body and the other on the left. The name vertebral artery is due to the fact that the blood vessel originates from the brachial artery and directs blood towards the cerebellum. In the process, the artery partially passes through the cervical vertebrae. Thus, the Latin term vertebra means “vertebra” in German. In total, the human brain receives blood from a total of four arteries, which include two vertebral arteries and two carotid arteries. If a vertebral artery becomes occluded, this usually does not have a negative effect on the brain because the opposite artery then continues to provide blood flow.
Anatomy and structure
It is not uncommon for the course of the vertebral artery to be asymmetrical. About half of people have a dominant vertebral artery on the left side of the body. In about 25 percent, the blood vessel occupies a dominant position on the right side of the body. The remaining 25 percent have a similar circumference in both vertebral arteries. The vertebral artery begins in the thoracic cavity at the first thoracic vertebra. From there, it runs between the longus colli muscle and the scalenus anterior muscle in the direction of the 6th cervical vertebra, where it reaches the skull via an opening in the foramen transversarium (lateral process of the cervical vertebrae). The foramina transversaria, which form a kind of chain, also bear the name transverse process canal. At this point, the vertebral nerve accompanies the vertebral artery. In addition, the course of the vertebral artery is parallel to the carotid artery. At the 1st cervical vertebra (atlas), the vertebral artery turns towards the posterior segment of the vertebral arch. In the process, the blood vessel is covered by the semispinalis capitis muscle. The entry of the vertebral artery into the skull takes place through the foramen magnum. This section is called the pars intracranialis. Inside the skull, the dura mater (hard meninges) is traversed by the vertebral artery. It runs medially into the anterior portion of the medulla oblongata (medulla oblongata). At the lower half of the pons (bridge), the right and left vertebral arteries are united to form the basilar artery (basilar artery). This, in turn, joins the cerebral arterial circulation.
Function and Tasks
One of the most important functions of the vertebral artery is to supply the brain with blood. In doing so, it divides into several branches. One of these branches arises before the union with the basilar artery. It serves to supply various sections of the cerebellum as well as the brain stem (truncus cerebri or truncus encephali) and is called the inferior posterior cerebellar artery. The anterior spinal artery also originates from the vertebral arteries. However, the inflows are not very constant, so that individually large fluctuations take place. Other branches of the vertebral artery are the posterior spinal artery, which supplies the spinal cord, and the rami meningeales, which are responsible for supplying the dura mater. The vertebral artery supply areas also include the medulla oblongata.
Diseases
The vertebral artery can sometimes be affected by disorders and diseases. Foremost among these is the vertebral artery syndrome. This is a central nervous symptom complex that results from a circulatory disturbance of the vertebral artery. Physicians distinguish between two different forms of arterial-vertebral syndrome. These are the vascular arteria vertebralis syndrome and the arteria vertebralis compression syndrome. In the vascular form, there is vascular stenosis (narrowing) due to arteriosclerosis (hardening of the arteries). Compression syndrome is associated with vascular compression. Possible originators are tumors, metastases of cancer, a herniated disc or degenerative changes in the region of the cervical spine.In the context of the arteria vertebralis syndrome, a symptom complex is manifested which is based on a reduced blood supply to the basilar section. The most significant symptom is vertigo, which starts in a seizure-like manner. If the patient suffers from a compression-related arteria vertebralis syndrome, the vertigo is not infrequently caused by rapid twisting head movements. Furthermore, unclear neurological accompanying symptoms are possible. These lead to the fact that the arteria vertebralis syndrome cannot be diagnosed clearly. These symptoms may include headaches in the back of the head, neck pain, tinnitus (ringing in the ears), visual disturbances, nausea, vomiting, sensory disturbances, and disturbances in movement coordination. Sometimes there is a risk that the affected person will fall to the ground in a seizure-like manner. To diagnose the arterial-vertebral syndrome, the physician performs a physical examination, checks the patient’s neurological status and checks the functions of the upper cervical joints. To determine the causes of the symptoms, the physician performs imaging procedures such as magnetic resonance imaging (MRI) of the cervical spine, duplex sonography or digital subtraction angiography. The treatment of a vertebral artery syndrome depends on the respective cause. For example, in the case of a vascular arteria vertebralis syndrome, in which there is a pronounced narrowing of the vertebral artery, stent implantation is usually performed. In case of arteria vertebralis compression syndrome, both conservative and surgical treatment is possible. Conservative therapy consists of chiropractic care, physical therapy exercises, and elimination of pain. If a herniated disc or tumor is present, surgery must be performed.