Lumbar
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223957936
2008-07-06T18:17:24Z
151.20.185.192
[[Image:Lumbar region in human skeleton.svg|right|250px]]
In [[anatomy]], '''lumbar''' is an [[adjective]] that means ''of or pertaining to the [[abdominal]] segment of the [[torso]], between the [[diaphragm (anatomy)|diaphragm]] and the [[sacrum]] ([[pelvis]])''. The five [[vertebrae]] in the lumbar region of the back are the largest and strongest in the movable part of the [[spinal column]], and can be distinguished by the absence of a foramen in the transverse process, and by the absence of facets on the sides of the body. In most [[mammal]]s, the lumbar region of the spine curves outward; this is called [[lordosis]].
The actual [[spinal cord]] (medulla spinalis) terminates between vertebrae one and two of this series, called L1 and L2. The [[central nervous system|nervous]] tissue that extends below this point are individual strands that collectively form the [[cauda equina]]. In between each lumbar vertebra a [[nerve]] root exits, and these nerve roots come together again to form the largest single nerve in the [[human body]], the [[sciatic nerve]]. The sciatic nerve runs through the back of each leg and into the feet. This is why a disorder of the low back that affects a nerve root, such as a [[spinal disc herniation]], can cause pain that radiates along the sciatic nerve ([[sciatica]]) down into the foot.
There are several [[muscle]]s in the low back that assist with rotation, flexibility and strength. These muscles are susceptible to injury, especially while lifting heavy objects, or lifting while twisting. A low back [[muscle strain]] can be extremely painful but will usually heal within a few days or weeks.
The lumbar portion of the spine bears the most body weight and also provides the most flexibility, a combination that makes it susceptible to injury and wear and tear over time. This is why low back pain is so prevalent.
==See also==
*[[Car seat]] and lumbar support
*[[Low back pain]]
*[[Lumbar Puncture]]
*[[Lumbar vertebrae]]
==External links==
*[http://www.medicinenet.com/low_back_pain/article.htm Lower back pain information]
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[[Category:Skeletal system]]
[[la:Lumbus]]
[[pt:Região lombar]]
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