Nerve Dermatome Mapdermatomes Nclex Radiculopathy Occupational Therapy Spinal Nerve – The term “dermatome” is a combination of 2 Ancient Greek words; “derma” implying “skin”, and “tome”, meaning “cutting” or “thin section”. It is an area of skin which is innervated by the posterior (dorsal) root of a single spinal nerve. As posterior roots are organized in sections, dermatomes are as well. This is why the term “dermatome” describes the segmental innervation of the skin.
Dermatomes Diagram Spinal Nerves And Locations – Dermatomes Diagram Spinal Nerves And Locations
Neighboring dermatomes typically, if not constantly overlap to some degree with each other, as the sensory peripheral branches corresponding to one posterior root typically surpass the limit of their dermatome. The thin lines seen in the dermatome maps are more of a scientific guide than a genuine boundary. Nerve Dermatome Mapdermatomes Nclex Radiculopathy Occupational Therapy Spinal Nerve
This suggests that if a single spinal nerve is impacted, there is likely still some degree of innervation to that sector of skin originating from above and below. For a dermatome to be entirely numb, generally two or 3 surrounding posterior roots require to be impacted. In addition, it’s important to note that dermatomes undergo a large degree of interindividual variation. A visual representation of all the dermatomes on a body surface chart is referred to as a dermatome map. Nerve Dermatome Mapdermatomes Nclex Radiculopathy Occupational Therapy Spinal Nerve
Dermatome maps
Dermatome maps portray the sensory distribution of each dermatome throughout the body. Clinicians can assess cutaneous sensation with a dermatome map as a way to localize sores within central nervous tissue, injury to particular spinal nerves, and to identify the extent of the injury. Numerous dermatome maps have been established over the years but are typically clashing.
The most frequently used dermatome maps in significant textbooks are the Keegan and Garrett map (1948) which leans towards a developmental interpretation of this principle, and the Foerster map (1933) which correlates much better with scientific practice. This article will examine the dermatomes using both maps, identifying and comparing the major differences between them.
Why Are Dermatomes Important?
To comprehend dermatomes, it is very important to understand the anatomy of the spine. The spine is divided into 31 segments, each with a pair (right and left) of anterior and posterior nerve roots. The types of nerves in the anterior and posterior roots are different.
Anterior nerve roots are accountable for motor signals to the body, and posterior nerve roots get sensory signals like discomfort or other sensory symptoms. The posterior and anterior nerve roots integrate on each side to form the spinal nerves as they exit the vertebral canal (the bones of the spinal column, or backbone).