Atlas Spine LLC- Anatomy of the Spine

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. It is made up primarily of vertebrae, discs, and the spinal cord. There are 33 vertebrae that make up the bony structure of the spinal column, The last four are fused together to make the tailbone. Each vertebrae is separated by a disc which acts as a cushion and a seal.

Acting as a conduit for the brain, signals are transmitted and received through the spinal cord. When an injury to the spinal cord occurs, the flow of information from that point down is stopped. This break in instructions to the arms, legs, and other parts of the body will prevent the person from moving, breathing and can obstruct or stop any sense of feel or touch.

The spinal column is separated in to five areas:

The Spinal Cord
The spinal cord is a long, thin, bundle of nervous tissue and cells that extend from the brain. The spinal cord extends down to the space between the first and second lumbar vertebrae. It does not, however, extend the entire length of the vertebral column. It is approximately 18 inches long in men and 17 inches long in women.

The primary function of the spinal column is to transmit neural signals between the brain and the rest of the body. It is protected by three layers of tissue called spinal meninges, which surround the cord. The dura mater is the outermost layer. Between the dura mater and the surrounding bone of the vertebrae is a space called the epidural space. It is filled with adipose tissue and it contains a network of blood vessels. The arachnoid is the middle protective layer. It's name comes from the fact that the tissue has a spiderweb-like appearance. The space between the arachnoid and the underlying pia mater is called the subarachnoid space. The subarachnoid space contains cerebrospiinal fluid. The pia mater is the inntermost protective layer. It is very delicate and it is tightly associated with the surface of the spinal cord.

Cervical Spine
The cervical spine begins at the base of the skull and acts as a bridge between the brain and the rest of the body. It supports the weight of the head and protects the nerves that come from the brain to the rest of the body. This section of the spine has seven vertebra that get smaller as they get closer to the base of the skull. The cervical spine is made up of 7 vertebrae (C1 - C7). Most of the rotation of the cervical spine comes from the top two segments. Most of the flexion and extension movements come from C5 - C7.

A complex set of ligaments, muscles and tendons exist to support the cervical spine. Ligaments help prevent excessive movement that would result in serious injury. The muscles help provide balance and stability to the spinal column and enable movement.

Thoracic Spine
The 12 vertebra in the upper back make up the thoracic spine. It provides stability and structural support to the upper back and allows very little motion. The thoracic spine is located in the chest area, is connected to the ribs and protects the vital organs of the heart and lungs.

Since the thoracic spine is not designed for motion, injuries to it are rare.

Lumbar Spine
The lower back (the lumbar spine) carries all the weight of the torso. It is the most frequently injured area of the spine. It has five vertebral bodies that extend from the lower spine to the sacrum. These vertebrae are the largest of the spine because they bear the majority of the body's weight.

Most people have 5 vertebrae in the lumbar spine, although it is not unusual to have six.

Sacrum
At the bottom of the lumbar spine is a bone called the sacrum. It makes up the back part of the pelvis. The sacrum is shaped like a triangle that fits between two halves of the pelvis, connecting the spine to the lower half of the body.

The sacrum is connected to part of the pelvis by sacroiliac joints.

The coccyx is located at the end of the spinal column. It is often referred to as the "tailbone". It consists of three to five vertebrae. These vertebrae may be fused together in groups or all together. It varies from person to person.