Gray matter 3)Anterior horn (column) Two groups of nuclei 后角固有核 ① Medial nuclear group 前角内侧核 present in most segments of 中间内侧核 spinal cord, innervating axial ∴ muscles 中间外侧核 ② Lateral nuclear group 前角外侧核 present only in cervical and lumbosacral enlargements enervating limb muscles 前角运动细胞Gray matter Two groups of nuclei ① Medial nuclear group 前角内侧核: present in most segments of spinal cord, innervating axial muscles. ② Lateral nuclear group 前角外侧核: present only in cervical and lumbosacral enlargements, innervating limb muscles 3) Anterior horn (column):