The anatomy of the spine consists of 33 bones called vertebrae composing the five regions of what is commonly known as the backbone. Vertebrae have a slight resemblance to doughnuts. They are flat, somewhat rounded bones that are open in the middle and stacked on top of each other. The five regions of the backbone are the cervical, thoracic, lumbar, sacral and coccyx spine, and they are each made up of a specific number of vertebrae. There are seven vertebrae in the cervical spine, 12 in the thoracic, five in the lumbar, five in the sacral and four in the coccyx spine, although some medical sources on the anatomy of the spine differ slightly regarding the exact number of vertebrae in each part.
People who are not healthcare providers generally know the anatomy of the spine better by the more common names for these regions: the neck, the ribs, the lower back, the back wall of the pelvis and the tailbone. The cervical spine is the neck, the thoracic spine is the ribs, and the lumbar area is the lower back. Vertebrae of the sacral spine make up the back wall of the pelvis, and those of the coccyx comprise the tailbone region. The spinal cord runs from the brain and down the back through the openings in the center of the stacked vertebrae.
The anatomy of the spine permits some vertebrae to be more susceptible to injury and damage than others. For example, the cervical spine is just seven vertebrae that must support the weight of a person's head. Another vulnerable region of the anatomy of the spine is the lumbar area. It is prone to injury because it is not supported by any other parts of the skeleton.
Injury to the cervical spine, especially to the high end closest to the brain, can prove fatal because control of the muscles involved in breathing arises from this area. Automobile accidents, particularly those in which a person's head is whipped back and forth, are among the incidents that can and often do result in some type of injury to the anatomy of the spine. Injury to any part of the spine could result in some form of paralysis because the anatomy does not just involve bone but also the spinal cord protected by that bone.