Dermatome | |
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![]() Dermatomes of the upper and lower limbs (modified, after Keegan, J. J., and Garrett, F. D.) | |
![]() Dermatomes of the upper parts of the body, displaying significant overlapping (modified, from Fender, after Foerster) | |
Anatomical terminology |
A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of any given spinal nerve.[1][2] There are 8 cervical nerves (C1 being an exception with no dermatome), 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Each of these nerves relays sensation (including pain) from a particular region of skin to the brain.
The term is also used to refer to a part of an embryonic somite.
Along the thorax and abdomen, the dermatomes are like a stack of discs forming a human, each supplied by a different spinal nerve. Along the arms and the legs, the pattern is different: the dermatomes run longitudinally along the limbs. Although the general pattern is similar in all people, the precise areas of innervation are as unique to an individual as fingerprints.
An area of skin innervated by a single nerve is called a peripheral nerve field.
The word dermatome is formed from Ancient Greek δέρμα 'skin, hide' and τέμνω 'cut'.