Regions of the Spine

Spine Anatomy:

Regions of the Spine

There are 33 vertebrae (bones) in the spine. Anatomically, the spine is divided into four regions:

• The top seven vertebrae that form the neck are called the cervical spine and are labeled C1-C7.
• The upper back, or thoracic spine, has 12 vertebrae, labeled T1-T12.
• The lower back, or lumbar spine has five vertebrae, labeled L1-L5.
• The sacrum and coccyx (tailbone) are made up of nine vertebrae that are fused together to form a solid bone. The sacrum is labeled S1.

Curves of the Spine

When viewed from the front or back, the normal spine is in a straight line, with each vertebra sitting directly on top of the other. A side-to-side curve in the spine is called a scoliosis.

When viewed from the side, the normal spine has three gradual curves:

• The neck has a lordosis; it curves toward the back.
• The thoracic spine has a kyphosis; it curves toward the front.
• The lumbar spine also has a lordosis.

These curves help the spine to support the load of the head and upper body, and maintain balance in the upright position.