The human spine is made up of 33 bones that house the spinal cord. The spine is divided up into five regions. Starting at the base of the head and moving towards the feet, the regions are called the cervical spine (7 articulating vertebrae), the thoracic spine (12 articulating vertebrae), the lumbar spine (5 articulating vertebrae), the sacrum (5 fused vertebrae), and the coccyx (4 fused vertebrae).
The cervical spine is attached to the base of the skull and makes up the “neck” portion of the spine. The individual vertebrae are numbered one through seven and are referred to as C1-C7.
The thoracic spine is the second region down from the skull. There are twelve thoracic vertebrae (T1 to T12) with articulations to the rib cage. The thoracic spine is in between the cervical and lumbar regions and makes up the “chest” region in humans.
The lumbar spine is below the thoracic section of the spine and bears the greatest amount of weight in humans. The lumbar region has five lumbar vertebrae (L1-L5).
The fourth section of the spine is the sacrum. The sacrum is made up of five compounded vertebrae levels (S1-S5). The sacrum is a unique region of the spine, as there are no discs separating the vertebrae. The pelvis is connected to the sacrum.
The fifth and final region of the spine is the coccyx or “tailbone.” The coccyx is attached to the sacrum by a fibrocartilaginous joint and consists of four fused vertebrae. The coccyx also lacks discs.
The five varying regions of the human spine function to lend support to the body by simultaneously providing ample rigidity and flexibilty. The spinal cord is housed in the spinal canal by the vertebrae. The spinal cord is an integral part of the central nervous system.
The spinal cord plays a role in the body’s ability to send messages from one region to another. Sensory information is received from nerve endings throughout the body, and that information is then transferred to the brain via chemical messengers. The spinal cord is very fragile, and thus, must be protected by the rigid, strong bones of the spinal column.