C1 is called Atlas and C2 is called Axis and the rest C3-C7 are more classic in their structure, having a body, pedicles, laminae, spinous processes, and facet joints. C1 and C2 provide a great amount of mobility  for the skull. C1 acts as a ring or washer that the skull rests upon and articulates in a pivotal joint with the dens or odontoid process of C2.

The cervical spine is much more mobile than the rest of the spine in the thoracic and lumbar regions. The cervical spine has transverse foramina in each vertebra for the vertebral arteries to reach the brain with their supply of blood. The function of the backbone or spinal column is to house and protect the spinal cord in its’ spinal canal created by the 33 vertebrae in the backbone.

The skull can move up and down due to the atlanto-occipital joint and the atlantoaxial joint is what allows the neck to turn or twist from left to right. The axis also sits upon the first intervertebral disc of the spinal column. All mammals except manatees and sloths have seven vertebrae, no matter the length of their neck.