The arteria vertebralis is one of the vessels that supply the brain with oxygen-rich blood from the heart. Its diameter is about 3-5mm. It is arranged in pairs, i.e. there is a right and a left vertebral artery, which finally unite to form the basilar artery.
This vessel mainly supplies brain sections located in the posterior fossa. These include areas of the cerebrum that are responsible for vision, such as the occipital lobe, or for hearing and speech comprehension, such as the temporal lobe. The cerebellum is also supplied by branches of the arteria vertebralis and the arteria basilaris.
This is particularly important for the balance and coordination of movement sequences. The upper (cranial) parts of the brain stem, the bridge (pons) and the diencephalon, are also supplied with blood from the basilar artery. These brain regions contain many cranial nerve nuclei, which are responsible for the functions of the facial and eye muscles and the sensory organs in the face, as well as nerve tracts that interconnect the coordination of movement sequences. Prior to its fusion into the basilar artery, the vertebral artery also gives off branches to supply the upper spinal cord and parts of the brain stem, the medulla oblongata. The medulla oblongata regulates basic and vital functions of the body such as respiratory and circulatory regulation and the gag reflex.
The arteria vertebralis is a branch of the subclavian artery, which also exists in pairs. It originates approximately at the level of the depression between the collarbone (clavicle), cervical muscles and cervical spine (supraclavicular fossa) and runs behind the front cervical muscle (scalenus muscle) to the cervical spine. At the level of the 6th cervical vertebra it enters an opening within this vertebra (Foramen transversarium).
All cervical vertebral bodies have this opening in their lateral extension (processus transversus), which is why the vertebral artery can pull along the cervical spine to the head relatively protected by these superimposed holes. The superimposed holes are also called the vertebral canal (Canalis vertebralis). At the head, the artery enters the posterior fossa through the foramen magnum at the transition from the neck to the head.
The arteria vertebralis is divided into four segments (V1-V4) from the beginning. Segment V1 describes the free course of the artery until it enters the intervertebral holes. This is where changes in the inner wall of the vessel such as calcifications in the context of arteriosclerosis occur.
In addition, it can happen that the vessel wall loses its elasticity due to aging processes and thus bends, which leads to (functional) occlusion. Segment V2 runs through the Canalis vertebralis and can be constricted here mainly by age-related changes in the cervical vertebrae. Segments V2 and V3 (area of the first cervical vertebra, where the vertebral artery wraps around the first cervical vertebra) are most at risk for external injuries, for example in accidents, due to their anatomical proximity to the cervical spine. The fourth segment is the section of the vertebral artery that runs inside the skull.