Difference between revisions of "Dermatome"

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<p>A <strong>Dermatome</strong> is an area of skin associated with a pair of dorsal roots from the spine. The significance of dermatomic regions is important as pain in a dermatomic area may indicate spinal damage or neurological stenosis. A compressed spinal nerve may show as pain elesewhere on the body, according to the dermatomic area covered by the compressed nerve. A similar area innervated by peripheral nerves is called a peripheral nerve field.</p>
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<p>The body can be divided into regions that are mainly supplied by a single spinal nerves. There are eight cervical (one for the head, and one for each cervical vertebra), twelve thoracic, five lumbar and five sacral spinal nerves.</p>
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<p>This innervates the body in a patterned form. Along the thorax and abdomen it is simply like a stack of discs forming a human, each supplied by a different spinal nerve.</p>
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<p>Along the arms and the legs, the pattern is different: the dermatomes run longitudinally along the limbs.</p>
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<p>&nbsp;</p>
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<h2><span class="editsection"></span><span class="mw-headline">Clinical significance</span></h2>
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<p>Dermatomes are useful in neurology for finding the site of damage to the spine. viruses that infect spinal nerves such as Herpes zoster infections (shingles), can reveal their origin by showing up as a painful dermatomic area. Herpes zoster, a virus that is dormant in the dorsal root ganglion, migrates along the spinal nerve to affect only the area of skin served by that nerve. Symptoms are usually unilateral but in the immune suppressed, they are more likely to become bilateral and symmetrical, meaning that the virus is present in both ganglia of a dorsal root ganglion pair.</p>
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<p>&nbsp;</p>
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<h2><span class="editsection"></span><span class="mw-headline">Important dermatomes and anatomical landmarks</span></h2>
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<ul>
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    <li>C6 - (median nerve) 1st digit (thumb) </li>
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    <li>C7 - (radial nerve) 2nd and 3rd digit </li>
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    <li>C8 - (ulnar nerve) 4th and 5th digit, also the funny bone </li>
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    <li>T4 - nipples. </li>
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    <li>T5 - Inframammary fold. </li>
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    <li>T6 - xiphoid process. </li>
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    <li>T10 - umbilicus. </li>
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    <li>T12 - pubic bone area. </li>
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</ul>
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<p>&nbsp;</p>
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<h2><span class="editsection"></span><span class="mw-headline">Additional images</span></h2>
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<table cellspacing="0" cellpadding="0" class="gallery">
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    <tbody>
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        <tr>
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            <td>
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            <div class="gallerybox" style="WIDTH: 155px">
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            <div class="thumb" style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 13px; WIDTH: 150px; PADDING-TOP: 13px">
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            <div style="MARGIN-LEFT: auto; WIDTH: 120px; MARGIN-RIGHT: auto"><img height="120" alt="" width="59" border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Gray797.png/59px-Gray797.png" /></div>
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            </div>
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            <div class="gallerytext">
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            <p>Distribution of cutaneous nerves. Ventral aspect.</p>
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            </div>
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            </div>
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            </td>
 +
            <td>
 +
            <div class="gallerybox" style="WIDTH: 155px">
 +
            <div class="thumb" style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 13px; WIDTH: 150px; PADDING-TOP: 13px">
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            <div style="MARGIN-LEFT: auto; WIDTH: 120px; MARGIN-RIGHT: auto"><img height="119" alt="" width="56" border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Gray798.png/56px-Gray798.png" /></div>
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            </div>
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            <div class="gallerytext">
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            <p>Distribution of cutaneous nerves. Dorsal aspect.</p>
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            </div>
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            </div>
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            </td>
 +
        </tr>
 +
    </tbody>
 +
</table>
 +
<table cellspacing="0" cellpadding="0" class="gallery">
 +
    <tbody>
 +
        <tr>
 +
            <td>
 +
            <div class="gallerybox" style="WIDTH: 155px">
 +
            <div class="thumb" style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 13px; WIDTH: 150px; PADDING-TOP: 13px">
 +
            <div style="MARGIN-LEFT: auto; WIDTH: 120px; MARGIN-RIGHT: auto"><img height="120" alt="" width="85" border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Gray811and813.PNG/85px-Gray811and813.PNG" /></div>
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            </div>
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            <div class="gallerytext">
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            <p>Cutaneous nerves of right upper extremity.</p>
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            </div>
 +
            </div>
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            </td>
 +
            <td>
 +
            <div class="gallerybox" style="WIDTH: 155px">
 +
            <div class="thumb" style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 13px; WIDTH: 150px; PADDING-TOP: 13px">
 +
            <div style="MARGIN-LEFT: auto; WIDTH: 120px; MARGIN-RIGHT: auto"><img height="120" alt="" width="111" border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/d/de/Gray812and814.PNG/111px-Gray812and814.PNG" /></div>
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            </div>
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            <div class="gallerytext">
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            <p>Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.</p>
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            </div>
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            </div>
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            </td>
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        </tr>
 +
    </tbody>
 +
</table>
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<p>&nbsp;</p>
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<h2><span class="editsection"></span><span class="mw-headline">See also</span></h2>
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<ul>
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    <li>Cutaneous innervation </li>
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    <li>Myotome </li>
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</ul>
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<p>&nbsp;</p>
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<h2><span class="editsection">E</span><span class="mw-headline">xternal links</span></h2>
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<ul>
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    <li><a title="University of Kansas" href="/wiki/University_of_Kansas">Hand kinesiology at UK</a> <em><a class="external text" title="http://classes.kumc.edu/sah/resources/handkines/nerves/dermatome.htm" rel="nofollow" href="http://classes.kumc.edu/sah/resources/handkines/nerves/dermatome.htm">nerves/dermatome.htm</a></em> </li>
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</ul>

Latest revision as of 13:14, 9 March 2008

A Dermatome is an area of skin associated with a pair of dorsal roots from the spine. The significance of dermatomic regions is important as pain in a dermatomic area may indicate spinal damage or neurological stenosis. A compressed spinal nerve may show as pain elesewhere on the body, according to the dermatomic area covered by the compressed nerve. A similar area innervated by peripheral nerves is called a peripheral nerve field.

The body can be divided into regions that are mainly supplied by a single spinal nerves. There are eight cervical (one for the head, and one for each cervical vertebra), twelve thoracic, five lumbar and five sacral spinal nerves.

This innervates the body in a patterned form. Along the thorax and abdomen it is simply like a stack of discs forming a human, each supplied by a different spinal nerve.

Along the arms and the legs, the pattern is different: the dermatomes run longitudinally along the limbs.

 

Clinical significance

Dermatomes are useful in neurology for finding the site of damage to the spine. viruses that infect spinal nerves such as Herpes zoster infections (shingles), can reveal their origin by showing up as a painful dermatomic area. Herpes zoster, a virus that is dormant in the dorsal root ganglion, migrates along the spinal nerve to affect only the area of skin served by that nerve. Symptoms are usually unilateral but in the immune suppressed, they are more likely to become bilateral and symmetrical, meaning that the virus is present in both ganglia of a dorsal root ganglion pair.

 

Important dermatomes and anatomical landmarks

  • C6 - (median nerve) 1st digit (thumb)
  • C7 - (radial nerve) 2nd and 3rd digit
  • C8 - (ulnar nerve) 4th and 5th digit, also the funny bone
  • T4 - nipples.
  • T5 - Inframammary fold.
  • T6 - xiphoid process.
  • T10 - umbilicus.
  • T12 - pubic bone area.

 

Additional images

Distribution of cutaneous nerves. Ventral aspect.

Distribution of cutaneous nerves. Dorsal aspect.

Cutaneous nerves of right upper extremity.

Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.

 

See also

  • Cutaneous innervation
  • Myotome

 

External links

Retrieved from "http://Opengenome.net/index.php?title=Dermatome&oldid=28869"