Ribs in the area of the cervical spine are originally formed in almost all terrestrial vertebrates . In the course of evolution , all terrestrial vertebrate groups, with the exception of snakes , have specialized in various spinal segments, with the ribs being receded in most areas and only preserved in their original form in the thoracic area . In the terrestrial vertebrates living today, free neck ribs only exist in crocodiles , bridge lizards, and within birds only in ratites (ratitae); in the other groups, the cervical ribs were reduced or fused with the cervical vertebrae. Except for the cervical vertebrae of ratites, the cervical ribs in the bird skeleton are in the form of short processes ( uncinate processes ).
Neck ribs in humans
In humans, as in all mammals , the cervical ribs are reduced and, together with the transverse processes of the cervical vertebrae, form small bony eyelets (foramina processus transversi) in which the vertebral artery runs. Real ribs only appear in the thoracic spine , where they are involved in the structure of the thorax (chest).
An atavistic cervical rib on the 7th cervical vertebra can be a harmless malformation . They are usually dorsally attached, stubby ribs with cartilaginous or connective tissue connection to the sternum . This training is found in around 1% of people and is usually symptom-free, but sometimes it also causes symptoms in the form of cervical rib syndrome .