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Image courtesy of flickr.com
The Vertebral Column

The vertebral column is extremely important to the human body. It is arguably the second most important group of bones in the body, second only to the essential cranial bones. All motor function that occurs below the brain depends on the cord of nerves that run through the 26 protective vertabrae. Quadrapalegics and parapalegics are all too familiar with the consequences of damage to the spinal cord.

Essential Functions

The vertebral column has three main functions. As the body's axial support, the vertebral column transmits the weight of the upper body, specifically the heavy skull/brain and the thoracic cage, onto the pelvis and femurs. It provides attachment points for all twelve ribs, as well as the various neck and back muscles. Most importantly, the vertebral column protects the fragile spinal cord.


General Structure

The verterbral column consists of 33 bones, the vertabrae. Only 24 of them are actually seperate. Five of them fuse to form the sacrum and the remaining four fuse to form the coccyx. The column is divided into three major sections or curvatures (does not include the sacrum/coccyx regions). The three curvatures are the cervical curvature, the thoracic curvature, and the lumbar curvature.

Cervical Curvature

7 vertabrae form the cervical region, C1 through C7. The atlas (C1) and the axis (C2) are the most notable vertabrae fournd in this region. The atlas connects with the skull at he occipital condyles, essentially carrying the skull. The name of this vertabrae is derived from Greek mythology. The axis directly below allows for the atlas to rotate.

Thoracic Curvature

The thoracic region of the vertebral column consists of 12 vertabrae. All 12 vertabrae articulate with the ribs, which form the thoracic cage, hence the name.

Lumbar Curvature

The last five individual bones form the lumbar region of the spine. These five vertabrae receive the most stress, and are therefore the strongest of the 24. They are also more rigid than the two superior curvatures.

Problems

Sometimes, the vertebral column is afflicted by abnormal curvature. The most common disorder of this type is called scoliosis. For more information, visit the National Scoliosis Foundation at www.**scoliosis**.org.