Head and Spine Anatomy

The spine is made up of vertebrae and cushions of soft tissue known as disks. When you see the spine in a side view, there are three distinct curves. The top curve in the neck area is known as the cervical curve. The thoracic curve is at the chest level. Finally, the lower back has the lumbar curve. Two fused bones are at the bottom of the spine: the sacrum and coccyx.

From the front or back, the spinal column should be straight. This keeps the body in balance and allows optimal comfort.


Cervical Vertebrae (C1-C7)

The cervical spine is further divided into two parts; the upper cervical region (C1 and C2), and the lower cervical region (C3 through C7). C1 is termed the Atlas and C2 the Axis.

The Atlas (C1) is the first cervical vertebra and is abbreviated C1. This vertebra supports the skull. It looks different than the rest of the vertebrae. The Atlas is a ring of bone made up of two lateral masses that are joined at the font and back by the anterior and posterior arches.
The Axis is the second cervical vertebra or C2. It has a blunt tooth-like structure that projects upward. This bone allows the head and Atlas to rotate around the "dens."


Thoracic Vertebrae (T1 - T12)

The thoracic vertebrae increase in size from T1 through T12.


Lumbar Vertebrae (L1 - L5)

The lumbar vertebrae graduate in size from L1 through L5. These vertebrae bear much of the body's weight.


Sacral Spine (S1 through S5)

The Sacrum is located behind the pelvis. These five bones are fused into a triangle shape that forms the sacrum. The sacrum fits between the two hipbones connecting the spine to the pelvis. The last of the lumbar vertebrae (L5) provides the movement for the sacrum. Right below the sacrum is five additional bones that are fused together to form the Coccyx, which is commonly known as the tailbone.