Cervical vertebrae

The cervical vertebrae ( cervical vertebrae Latin ) make up the head side ( cranial ) end of the spine of vertebrates and are the most movable vertebrae between the thoracic spine and the head. This portion is referred to as the cervical spine.

Number

Mammals have seven cervical vertebrae in the rule. This applies to the long neck of the giraffe as well as whales, but also for small mammals such as shrews. Man also has seven cervical vertebrae, which are abbreviated in medicine with the letter C (C1 to C7). Manatees and the Hoffmann- Two -toed sloth ( Choloepus hoffmanni ) have the only mammals only six cervical vertebrae. In three -toed animals three to four thoracic vertebrae are shifted, which is why you ran out of up to ten neck vertebrae long. In birds, the number of cervical vertebrae varies between ten and 26 (see also bird skeleton).

The largest cervical vertebrae ever found a land vertebrate was the eighth cervical vertebra of Sauroposeidon, which was 1.4 m long.

Head joint

The two head next vertebrae of the cervical spine differ morphologically from the rest of the cervical vertebrae, which mostly correspond to the uniform plan of a vortex: the top vertebrae, the atlas or " Nicker " - has the shape of a ring. Its mission is to carry the head. (Also called " spin ") of the second cervical vertebra, the axis, together with the Atlas, the two components in the lower head joint, the so-called articulationes atlantoaxiales et median lateral. When the head is turned sideways, the atlas ring rotates around the Axiszahn ( dens ).

Anatomy

The remaining 5 cervical vertebrae have as a feature in humans hook extensions, Unci corporis (singular uncus corporis ), sometimes referred to as uncinate process, the raise in the first decade of life and leads to formation of a gap between the vertebrae and the Unci, the unkovertebralen columns or Unkovertebralgelenken. With the exception of the first and sometimes second thoracic vertebra all other vertebrae are nearly planar at the surfaces. A disturbance of the vortex system can lead to Unkovertebralarthrosen and significant movement limitations to nerve or Gefäßeinklemmung the Klippel -Feil syndrome, or at an advanced age in these transitions, since the Unci corporis are spatially adjacent to the Spinalnervenrinne ( sulcus nervi spinalis).

Another special feature of the cervical vertebrae are the foramina transversaria (singular: transverse foramen ) which after a Durchtrittsort for the vertebral artery ( from the 6th to the 1st cervical vertebra ) to the top and for the venous plexus of the vertebral vein from 1st to 7th vertebrae serve below.

The seventh cervical vertebra is the vertebra prominens because it has the most protruding ( towards the back ) spinous process and usually is easily felt. On her and on 6 sometimes even short ribs approaches may be present, so-called cervical ribs can lead to difficulties ( cervical rib syndrome).