The vertebrae are the irregular bones that create the spinal column. These irregular bones are divided into four sections which are the cervical, thoracic, lumbar, and sacral or pelvic spine sections, which are also referred to as curvatures. There are seven vertebrae that make up the cervical spine (neck); twelve vertebrae that make up the thoracic spine (chest); five vertebrae that make up the lumbar spine (waist); and finally there are five fused vertebrae that make up the sacrum and three vertebrae that make up the coccyx (tail bone) that combined make up the sacral or pelvic spine (Bridwell, 2012). These numbers are for an adult spine. In the infant spine, the sacral spine is actually in five vertebrae that have not fused into one which happens by the age of 30 (Martini & Nath, 2009, p. 234).
The vertebrae are referred to or abbreviated as C1-C7 for the cervical vertebrae; T1-T12 for the thoracic vertebrae; L1-L5 for the lumbar vertebrae; S1-S5 for the sacral vertebrae. The coccyx or tail bone does not have an abbreviation (Bridwell, 2012).
Cervical Vertebra:
Cervical vertebrae are the smallest out of the entire spinal column. The size is determined by the comparison of body of the vertebrae to the vertebral foramen or the area where the spinal cord travels through in the center of the spinal column. The vertebral foramen is larger at the top of the spinal column and gets smaller the further it travels downward. The vertebral arch diameter also follows suit (Martini & Nath, 2009, p. 234). The cervical vertebrae are supportively responsible only for the weight of the person’s head and do not need to be bigger in size. Each of the cervical vertebrae has a concave upper surface of the body.
Keep in mind that the first cervical vertebra is called the atlas and the second is called the axis. The atlas has no spinous process which
References: Bridwell, K. MD. (2012). Vertebral column. Retrieved from: http://www.spineuniverse.com/anatomy/vertebral-column Martini, F., & Nath, J. L. (2009). Fundamentals of anatomy & physiology. San Francisco: Pearson/Benjamin Cummings.