Spine Anatomy

Anatomy of the Spine

The spine consists of 33 vertebrae. Vertebrae in the cervical, thoracic, and lumbar spine articulate with each other to allow movement within the spine. The vertebrae in the sacrum and coccyx are fused and do not allow movement. Neither the sacrum nor coccyx has intervertebral discs between the vertebrae.

Cervical Spine
The cervical spine consists of seven vertebrae known as C1 to C7.
Thoracic Spine
The thoracic spine consists of twelve vertebrae known as T1 to T12 that serve as attachment for the rib cage.
Lumbar Spine
The lumbar spine consists of five vertebrae known as L1 to L5.
Sacrum or Sacral Spine
The sacrum consists of five fused vertebrae known as S1 to S5.
Coccyx
The coccyx consists of four small, fused vertebrae.
Kyphosis
The forward rounding of the spine.
Lordosis
The backward rounding of the spine.

Vertebral Body
The cylinder shaped vertebral body is the weight-bearing structure of the vertebra.
Lamina
The flat plates of the lamina create the back wall of the vertebral canal and help protect the spinal cord.
Facet
The facet is a joint that attaches the rear section of the vertebra to those above and below.
Pedicles
Pedicles connect the lamina to the vertebral body.
Transverse Process
Transverse processes extend from the sides of each vertebra. Muscles and ligaments that move and stabilize the vertebrae attach to the transverse processes.
Spinous Process
The spinous process protrudes from the back of each vertebra. The spinous processes are the bumps that one can see or feel down the middle of one's back.  Muscles and ligaments that move and stabilize the vertebrae attach to the spinous processes.
Vertebral Canal
The spinal cord sits in this channel formed by the lamina and the vertebral body.

Intervertebral Disc
The intervertebral discs act as shock absorbers and are found between the vertebrae. A disc is made of the NUCLEUS, a gelatinous center, which is surrounded by the ANNULUS, a tough fibrous outer ring.

Spinal Cord
The spinal cord is protected by the spine and gives rise to nerve roots that carry signals, such as pain, from the arms, legs, and organs to the brain.
Nerve Root
Nerve roots are used to transmit information between the spinal cord and other parts of the body, such as arms, legs and organs.
Foramen
An opening through bone, which allows passage of nerve roots or blood vessels.

Sacroiliac Joint
The sacroiliac joint attaches the spine to the pelvis.
Sciatic Nerve
A large nerve fiber that begins in the lower back and runs through the buttock and down the lower limb. It is the largest nerve in the body.


This information is not designed to replace a physician's independent decision about the appropriateness or risks of a procedure for a given patient. Always consult your doctor about your back problem or medical conditions. Life Spine does not provide medical advice, diagnosis or treatment.