脊髓灰質內的背核(Nucleus dorsalis)其軸突(Axons)形成:
背側脊髓小腦徑路(Dorsal spinocerebellar tract)
腹側脊髓小腦徑路(Ventral spinocerebellar tract)
脊髓視丘徑路(Spino thalamic tract)
脊髓網狀徑路(Spino reticular tract)