Nerve Dermatome Map12 6e Dermatomes Medicine Libretexts

Nerve Dermatome Map12 6e Dermatomes Medicine LibretextsThe term “dermatome” is a mix of two Ancient Greek words; “derma” implying “skin”, and “tome”, suggesting “cutting” or “thin section”. It is a location of skin which is innervated by the posterior (dorsal) root of a single back nerve. As posterior roots are arranged in sections, dermatomes are. This is why the term “dermatome” describes the segmental innervation of the skin.

Nerve Dermatome Map12 6e Dermatomes Medicine Libretexts

12 6E Dermatomes Medicine LibreTexts – 12 6E Dermatomes Medicine LibreTexts

Surrounding dermatomes often, if not constantly overlap to some degree with each other, as the sensory peripheral branches corresponding to one posterior root typically exceed the limit of their dermatome. As such, the thin lines seen in the dermatome maps are more of a medical guide than a genuine limit. Nerve Dermatome Map12 6e Dermatomes Medicine Libretexts

This implies that if a single spinal nerve is impacted, there is likely still some degree of innervation to that segment of skin originating from above and listed below. For a dermatome to be completely numb, usually two or 3 neighboring posterior roots require to be impacted. In addition, it’s important to keep in mind that dermatomes go through a large degree of interindividual variation. A visual representation of all the dermatomes on a body surface area chart is described as a dermatome map. Nerve Dermatome Map12 6e Dermatomes Medicine Libretexts

Dermatome maps

Dermatome maps portray the sensory circulation of each dermatome throughout the body. Clinicians can examine cutaneous feeling with a dermatome map as a method to localize sores within central worried tissue, injury to specific spine nerves, and to identify the extent of the injury. Several dermatome maps have actually been established over the years but are often clashing.

The most commonly used dermatome maps in significant books are the Keegan and Garrett map (1948) which leans towards a developmental interpretation of this idea, and the Foerster map (1933) which correlates better with scientific practice. This article will review the dermatomes using both maps, recognizing and comparing the major differences between them.

Why Are Dermatomes Important?

To comprehend dermatomes, it is very important to comprehend the anatomy of the spine. The spinal column is divided into 31 segments, each with a set (right and left) of anterior and posterior nerve roots. The kinds of nerves in the anterior and posterior roots are various.

Anterior nerve roots are responsible for motor signals to the body, and posterior nerve roots receive sensory signals like discomfort or other sensory symptoms. The posterior and anterior nerve roots combine on each side to form the back nerves as they exit the vertebral canal (the bones of the spine, or backbone).