Dermatomes and myotomes

Dermatomes

A dermatome refers to an area of skin which is innervated by sensory fibers from the posterior (dorsal) root of a single spinal nerve. 

Apart from the spinal nerve C1 and sometimes the coccygeal nerve (spinal nerve Co) that do not have an associated dermatome, the posterior root of each spinal nerve supplies a segment of skin. Spinal nerves C2-S5, thus, provide sensory innervation to the skin of the entire body, except for the face, which is supplied by the trigeminal nerve (CN V).

A dermatome map is a graphical representation of all the dermatomes on a body surface chart. The two most common dermatome maps that are often depicted in textbooks are the Keegan and Garrett map (1948) and the Foerster map (1933).

This video will help you learn more about the dermatomes of the body using the two most widely used variations of dermatome maps.

Take a closer look at the dermatomes of the human body below. 

Myotomes

A myotome describes a group of skeletal muscles which are innervated by somatic motor nerves from the anterior (ventral) nerve root of a single spinal nerve. Myotomes are often described as the motor equivalent of a dermatome.

Take a look at an overview of the myotomes of the human body below.

Take a quiz

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Browse atlas

Take a look at our atlas gallery to further review dermatomes and myotomes of the human body. 

Summary