Cervical spine
The cervical spine (HWS) consists of seven vertebrae. These are located directly below the skull and represent the most mobile part of the spinal column. The cervical spine bears the main load of the skull. The first two vertebrae of the cervical spine, Atlas and Axis, are the only vertebrae that deviate significantly from the basic vertebral structure.
Anatomy
The cervical spine is the uppermost and most mobile part of the Spine . It has seven cervical vertebrae, of which the first and second cervical vertebrae (Atlas and Axis) deviate significantly from the basic form. Together with the base of the skull, the two cervical vertebrae form the upper and lower head joint (bicondylar joint). In contrast to the other vertebrae, the atlas has no vertebral body. Furthermore, there is no intervertebral disc between the first two cervical vertebrae.
The remaining five cervical vertebrae have a relatively small and almost cuboid vertebral body. The associated vertebral foramen is triangular and large compared to the vertebral body.
The marginal surfaces of the vertebral body are inclined in a saddle-like manner and rise at the cranial surfaces (procc. uncinatus), which, however, only become visible in the tenth year of life.
The cervical vertebrae three to six have a forked spinous process which is relatively short. The seventh cervical vertebra is called vertebra prominens (protruding vertebra) because its spinous process protrudes a little further than in the other six cervical vertebrae. It can be clearly felt from the outside and therefore serves as a point of orientation. The vertebral arteries (arteriae vertebrales) run through the transverse processes of the cervical spine. Together with the internal carotid arteries, they ensure the supply of blood to the brain. The cranial surface of the transverse process has a groove from the third cervical vertebra onwards, the sulcus n. spinalis. The spinal nerve is located in this groove.
Movements
Atals and axis together with the base of the skull form the upper and lower cervical joints. The connection between the occipital bone and the first cervical vertebra is the upper cervical joint. This connection is surrounded by a loose joint capsule and is held in place by ligaments between the occipital bone and the anterior and posterior arches of the atlas. This creates a range of motion of the joint of about 20° (forward and backward).
The lower head joint consists of three separate joints:
- the first between the tooth (dens) of the axis vertebra, the anterior arch of the first cervical vertebra and a ligament (Ligamentum cruciforme atlantis) in the atlas
- the second and third left and right between the joint surfaces of the first cervical vertebra and the axis vertebra
Somit erlaubt das untere Kopfgelenk zusammen mit einer schmalen Gelenkkapsel eine Bewegungsfreiheit von 30° nach rechts und links.
Funktion
Die Halswirbelsäule dient dazu, den Schädel zu tragen und trotzdem eine Beweglichkeit zu ermöglichen. An der Halswirbelsäule entspringen ebenfalls acht Rückenmarksnerven. Davon versorgen die oberen vier den Hals und die dazu gehöhrige Muskulatur sowie das Zwerchfell. Mit der Halswirbelsäule werden die aufsteigenden Blutgefäße sowie das Rückenmark geschützt.
