Dermatome Levels Chart – The term “dermatome” is a combination of 2 Ancient Greek words; “derma” implying “skin”, and “tome”, indicating “cutting” or “thin sector”. It is a location of skin which is innervated by the posterior (dorsal) root of a single spinal nerve. As posterior roots are organized in sections, dermatomes are. This is why the term “dermatome” refers to the segmental innervation of the skin.
Dermatomes Diagram Spinal Nerves And Locations – Dermatomes Diagram Spinal Nerves And Locations
Surrounding dermatomes frequently, if not constantly overlap to some degree with each other, as the sensory peripheral branches corresponding to one posterior root normally go beyond the limit of their dermatome. As such, the thin lines seen in the dermatome maps are more of a medical guide than a real boundary. Dermatome Levels Chart
This means that if a single spinal nerve is affected, there is likely still some degree of innervation to that sector of skin originating from above and listed below. For a dermatome to be completely numb, typically two or 3 surrounding posterior roots need to be impacted. In addition, it’s essential to note that dermatomes go through a large degree of interindividual variation. A visual representation of all the dermatomes on a body surface chart is described as a dermatome map. Dermatome Levels Chart
Dermatome maps
Dermatome maps depict the sensory distribution of each dermatome throughout the body. Clinicians can examine cutaneous sensation with a dermatome map as a way to localize sores within main nervous tissue, injury to specific spine nerves, and to identify the level of the injury. Several dermatome maps have actually been established for many years however are frequently conflicting.
The most typically used dermatome maps in significant textbooks are the Keegan and Garrett map (1948) which leans towards a developmental interpretation of this concept, and the Foerster map (1933) which correlates better with scientific practice. This post will review the dermatomes utilizing both maps, determining and comparing the major distinctions between them.
Why Are Dermatomes Important?
To understand dermatomes, it is important to comprehend the anatomy of the spinal column. The spinal column is divided into 31 sections, each with a set (right and left) of posterior and anterior nerve roots. The types of nerves in the posterior and anterior roots are different.
Anterior nerve roots are responsible for motor signals to the body, and posterior nerve roots get sensory signals like pain or other sensory symptoms. The posterior and anterior nerve roots integrate on each side to form the back nerves as they leave the vertebral canal (the bones of the spinal column, or backbone).