Back Anatomy

Back Pain Management logo
Take control of back pain.
man with back pain
Basic Anatomy of the back

Back Anatomy

Basic Anatomy of the Spine.

The Spinal Column:

The spinal column (also called the vertebral column) contains and protects the spinal cord and supports the body and head. The spinal column is flexible to allow movement of the body.

The spinal column is comprised of a column of small bones called vertebrae.

Shock absorbing discs separate the vertebrae

Facet Joints:

Facet joints (commonly called spinal joints) join adjacent vertebrae. Facet joints are hinge-like and allow adjacent vertebrae to move on one another to allow bending and twisting and also keep the spine within a normal range of motion. The surfaces of the bones that make up the facet joints are coated with smooth cartilage that allows the bones to glide smoothly against each other. Muscles, ligaments and discs support the joints of the spine.


Ligaments are tough bands of connective tissue that connect the vertebrae. Facet joints and ligaments help protect the spine by limiting how far the spine can bend or twist.


Muscles support the spine and allow movement. Muscles of the back, abdomen and buttocks stabilize the spine and maintain proper posture. Muscles protect the spine by absorbing shock before it reaches the discs and facet joints.

Spinal Cord:

The spinal cord begins at the brain and runs down to the level of the second lumbar vertebrae. The lumbar spinal nerves join to form the sciatic nerve. Spinal nerves branch out form the spinal cord.

Sciatic nerve:

The sciatic nerve branches off nerve roots off the lower end of the spinal cord. (The spinal cord ends in the lower back) Two branches run through the pelvis, deep into each side of the buttocks, through the hip, the backside of the upper leg down to the foot. . The sciatic nerve is the largest nerve in the human body - the diameter of a finger.


The 24 vertebrae are named according to their location along the spine. We start out with 33 vertebrae but the lowest nine fuse together to form single bones- 5 fused vertebrae form the sacrum and 4 tiny fused vertebrae form the coccyx (tailbone).

The 24 vertebrae:

Cervical spine (neck area) with 7 vertebrae (labeled C1 - C7)

Thoracic spine (chest area) with 12 vertebrae (labeled T1 - T12)
Lumbar spine (lower back) with 5 vertebrae (labeled L1 - L5)

Below the lumbar spine:

Sacrum: a triangular shaped solid base with 5 fused vertebrae - connects with the pelvis

Coccyx: (the tailbone) with 4 very small fused vertebrae.


The vertebrae are separated by shock absorbing intervertebral discs. Theses discs have a tough outer coating with and contain a jelly-like substance.

Back to the Top ^

Back Pain Home Page

Powered by World Connect Hosting a Division of INT Communications © 2004
© 2004 All Rights Reserved. / Back Anatomy