The myotome and dermatome have a nerve component. The hypaxial myotome forms the abdominal muscles. Adductor longus is derived from the myotome of spinal roots L2, L3, and L4. In anatomy the myotome is the motor equivalent of a dermatome. A myotome is the group of muscles that a single spinal nerve innervates. The myotome is that part of a somite that forms the muscles of the animal.