The healthy spine is strong and flexible. The spine supports the body and protects the spinal cord. The spine allows flexibility and free movement and provides points of attachment for muscles and ligaments (Harvey 2005).
Lumbar Spine
SPINAL COLUMN
The lumbar spine is formed by five vertebrae. The vertebrae are commonly referred to as L1 through L5. Each of these vertebrae are stacked on top of the other, with a gel like cushion called the intervertebral disc in between. The discs help to absorb pressure, distribute stress, and keep the vertebrae from grinding against each other. The vertebrae and discs are held together by groups of ligaments. Each vertebra has a bony arch that encircles the spinal canal. It is composed of one spinous process and two pedicles, two laminae, two sets of facet joints and two transverse processes. The bony arch provides the support necessary for upright posture (Strayer 2006).
SPINAL CANAL
In the center of the spinal column is a vertical hole called the spinal canal; it contains the spinal cord. The bony arch of the vertebra that encircles the spinal canal help to protect the spinal cord from injury by acting as armour. Branching off from the spinal cord are nerve roots. The lumbar and sacral nerve roots are called the cauda equina and exit off the spinal cord at the conus medullaris. This large fanning bundle of nerve roots communicates with the lower extremities and also controls bowel, bladder and sexual function (Strayer 2006).
http://orthoinfo.aaos.org
The lumbar spine is formed by five vertebrae. The vertebrae are commonly referred to as L1 through L5. Each of these vertebrae are stacked on top of the other, with a gel like cushion called the intervertebral disc in between. The discs help to absorb pressure, distribute stress, and keep the vertebrae from grinding against each other. The vertebrae and discs are held together by groups of ligaments. Each vertebra has a bony arch that encircles the spinal canal. It is composed of one spinous process and two pedicles, two laminae, two sets of facet joints and two transverse processes. The bony arch provides the support necessary for upright posture (Strayer 2006).
SPINAL CANAL
In the center of the spinal column is a vertical hole called the spinal canal; it contains the spinal cord. The bony arch of the vertebra that encircles the spinal canal help to protect the spinal cord from injury by acting as armour. Branching off from the spinal cord are nerve roots. The lumbar and sacral nerve roots are called the cauda equina and exit off the spinal cord at the conus medullaris. This large fanning bundle of nerve roots communicates with the lower extremities and also controls bowel, bladder and sexual function (Strayer 2006).
http://orthoinfo.aaos.org
Dermatonal distribution of lumbar nerve roots
This illustrates the dermatonal distribution of lumbar nerve roots. Where there is compression of the nerve root, pain and/or numbness may occur along the area of dermatonal disrtibution (Strayer 2006). Eg. If compression occurs at L4 level of the spine pain and/or numbness may be experienced in the lower back, thighs, and feet.
http://www.maturespine.com/symptoms/sciatica.html
http://www.maturespine.com/symptoms/sciatica.html
This is only a basic overview of the anatomy of the lumbar spine. For further information please see "Strayer, A, 2006. Lumbar spine surgery a guide to preoperative and postoperative patient care AANN reference series for clinical practice. American association of neuroscience nurses, 1-40."