Nervengebiet

Nervengebiet, literally "nerve territory," is the geographic area of the body that is innervated by a single nerve or nerve root. It encompasses sensory and motor components and is a key concept in anatomy, neurophysiology, and clinical diagnosis. In German medical usage it is closely related to dermatomes and myotomes.

Spinal nerves create dermatomes, which describe the skin areas that convey sensory information from a specific dorsal root. Motor fibers from the corresponding ventral root and the peripheral nerve supply the muscles in that region, forming a myotome. In practice, nerves often supply overlapping nervengebiete, especially in the limbs, so borders are not sharply defined.

Examples include the axillary nerve, whose nervengebiet includes the lateral shoulder area (sensory) and the deltoid muscle (motor); the median nerve, with sensation on the palmar side of the thumb, index, middle, and half of the ring finger and motor control of many forearm flexors and some intrinsic hand muscles; and the sciatic nerve, which covers a large posterior limb territory with its tibial and common fibular branches.

Clinically, localizing deficits to a nervengebiet helps diagnose nerve injuries and radiculopathies. Sensory loss, weakness, or altered reflexes within a territory guide management, including rehabilitation, decompression, or targeted nerve repair.

Map borders are estimates; individual variation is common. Nerve conduction studies, electromyography, and imaging improve accuracy when assigning symptoms to a specific nervengebiet.