Dermatome Hand Map – The term “dermatome” is a mix of 2 Ancient Greek words; “derma” suggesting “skin”, and “tome”, suggesting “cutting” or “thin segment”. It is an area of skin which is innervated by the posterior (dorsal) root of a single spinal nerve. As posterior roots are arranged in sectors, dermatomes are. This is why the term “dermatome” describes the segmental innervation of the skin.
Dermatomes Neurology Medbullets Step 1 – Dermatomes Neurology Medbullets Step 1
Neighboring dermatomes often, if not always overlap to some degree with each other, as the sensory peripheral branches corresponding to one posterior root usually surpass the limit of their dermatome. As such, the thin lines seen in the dermatome maps are more of a clinical guide than a genuine boundary. Dermatome Hand Map
This means that if a single back nerve is affected, there is most likely still some degree of innervation to that sector of skin coming from above and below. For a dermatome to be completely numb, normally 2 or three 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 Hand Map
Dermatome maps
Dermatome maps illustrate the sensory circulation of each dermatome across the body. Clinicians can assess cutaneous experience with a dermatome map as a method to localize sores within central worried tissue, injury to specific spinal nerves, and to identify the level of the injury. Several dermatome maps have been established throughout the years however are often conflicting.
The most typically utilized dermatome maps in major books are the Keegan and Garrett map (1948) which leans towards a developmental analysis of this principle, and the Foerster map (1933) which associates better with medical practice. This article will review the dermatomes utilizing both maps, recognizing and comparing the major distinctions between them.
Why Are Dermatomes Important?
To understand dermatomes, it is essential to understand the anatomy of the spinal column. The spinal column is divided into 31 segments, each with a pair (right and left) of anterior and posterior nerve roots. The types of nerves in the posterior and anterior roots are various.
Anterior nerve roots are responsible for motor signals to the body, and posterior nerve roots get sensory signals like pain or other sensory signs. The anterior and posterior nerve roots integrate on each side to form the spine nerves as they exit the vertebral canal (the bones of the spinal column, or backbone).