Cervical Dermatome Chart – The term “dermatome” is a combination of two Ancient Greek words; “derma” suggesting “skin”, and “tome”, indicating “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 sectors, 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
Surrounding dermatomes frequently, if not always overlap to some degree with each other, as the sensory peripheral branches representing one posterior root generally exceed the limit of their dermatome. The thin lines seen in the dermatome maps are more of a clinical guide than a real boundary. Cervical Dermatome Chart
This indicates that if a single spine nerve is impacted, there is most likely still some degree of innervation to that sector of skin coming from above and listed below. For a dermatome to be entirely numb, typically two or three neighboring posterior roots need to be impacted. In addition, it’s important to note that dermatomes go through a big degree of interindividual variation. A visual representation of all the dermatomes on a body surface chart is referred to as a dermatome map. Cervical Dermatome Chart
Dermatome maps
Dermatome maps portray the sensory distribution of each dermatome throughout the body. Clinicians can examine cutaneous sensation with a dermatome map as a way to localize lesions within central nervous tissue, injury to specific spine nerves, and to identify the degree of the injury. A number of dermatome maps have been developed throughout the years however are often clashing.
The most commonly used dermatome maps in significant textbooks are the Keegan and Garrett map (1948) which leans towards a developmental analysis of this concept, and the Foerster map (1933) which correlates better with scientific practice. This article will evaluate the dermatomes utilizing both maps, recognizing and comparing the significant differences between them.
Why Are Dermatomes Important?
To understand dermatomes, it is essential to understand the anatomy of the spine. The spinal column is divided into 31 sectors, each with a pair (right and left) of posterior and anterior nerve roots. The types 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 get sensory signals like discomfort or other sensory signs. The posterior and anterior nerve roots combine on each side to form the spinal nerves as they leave the vertebral canal (the bones of the spine, or backbone).