Dermatomes of the Upper and Lower Limbs (Modified, after Keegan, J. J., and Garrett, F. D.) According to the clinical, surgical, and experimental findings of Keegan and Garrett, the dermatomes of the limbs from the 5th cervical to the 1st thoracic, and from the 3rd lumbar to the 2nd sacral extend as a series of bands from the mid-dorsal line of the trunk into the limbs, as illustrated. When the function of even a single dorsal nerve root is interrupted, faint but definite diminution of sensitivity can be demonstrated in the dermatome. The best method to detect and plot the area of diminished sensitivity is by the use of light pin scratch for pain sensation, although it can be found for temperature and for tactile sensation also. #Diagnosis #Anatomy #Dermatomes #Dermatomal #Nerves #Roots
