The spinal cord Gray matter P央管胸核 胶状质 Posterior horn(column) 后角边缘核 Posteromarginal nucleus 后角固有核 后角边缘核 Substantia gelatinosa胶状质 Nucleus proprius后角固有核 中间内侧核 Nucleus thoracicus(dorsalis)I 网状结 胸核(背核) in segments 中间外侧核 C8~L3Gray matter 1) Posterior horn (column): The spinal cord Posteromarginal nucleus 后角边缘核 Substantia gelatinosa 胶状质 Nucleus proprius 后角固有核 Nucleus thoracicus (dorsalis) 胸核（背核）in segments C8~L3