The spinal column is composed of 33 vertebrae, which are distributed as:
- Cervical vertebrae – 7
- Thoracic vertebrae – 12
- Lumbar vertebrae – 5
- Sacrum – 5
- Coccyx – 4
The vertebrae from the cervical, thoracic and lumbar are distinct yet possess some basic common features. The vertebra is a ring-like structure with a body, a canal and bony projections.
The vertebral body is a solid bony mass which helps in the function of weight bearing. It has end plates on either end to provide for growth and nutrition. It is connected to the intervertebral disc.
The spinal canal is the hollow within the ring, through which the spinal cord passes down. The spinal nerves emerge from this and pass out from the intervertebral foramen which is the space between the 2 vertebral bodies.
The bony projections include the spinous process which is the pointed thing that is felt at the back when we run our hand over it. The lateral processes emerge at the side providing attachments for spinal musculature and adding to the stability. The superior and inferior articular processes are the projections that participate in the joints that connect two vertebrae to each other.
The regional differences of the vertebrae are significant as they prepare the vertebrae for the specific functions of the region.