Dermatome Chart Upper Limb

Dermatome Chart Upper LimbThe term “dermatome” is a mix of 2 Ancient Greek words; “derma” indicating “skin”, and “tome”, suggesting “cutting” or “thin section”. It is an area of skin which is innervated by the posterior (dorsal) root of a single back nerve. As posterior roots are arranged in sectors, dermatomes are. This is why the term “dermatome” describes the segmental innervation of the skin.

Dermatome Chart Upper Limb

Dermatomes Neurology Medbullets Step 1 – Dermatomes Neurology Medbullets Step 1

Surrounding dermatomes often, if not always 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 scientific guide than a genuine boundary. Dermatome Chart Upper Limb

This implies that if a single spine nerve is impacted, there is likely still some degree of innervation to that segment of skin coming from above and listed below. For a dermatome to be completely numb, usually 2 or 3 neighboring posterior roots need to be affected. In addition, it’s important to note that dermatomes undergo 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. Dermatome Chart Upper Limb

Dermatome maps

Dermatome maps depict the sensory distribution of each dermatome across the body. Clinicians can examine cutaneous sensation with a dermatome map as a way to localize lesions within central anxious tissue, injury to specific spine nerves, and to figure out the level of the injury. A number of dermatome maps have been established over the years but are often contrasting.

The most typically used dermatome maps in major textbooks are the Keegan and Garrett map (1948) which leans towards a developmental analysis of this concept, and the Foerster map (1933) which associates much better with scientific practice. This post will evaluate the dermatomes utilizing both maps, recognizing and comparing the major distinctions in 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 sections, each with a set (right and left) of anterior and posterior 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 receive sensory signals like pain or other sensory symptoms. The anterior and posterior nerve roots combine on each side to form the back nerves as they leave the vertebral canal (the bones of the spinal column, or backbone).