成人尸体１５具，其中男尸６具，女尸９具，共３０侧，分别去其头、颈和四肢，取出胸腔器官，从背部人路进行解剖，直至切除椎弓，暴露硬膜囊和椎间孔，打开硬膜囊，并追随后根直至椎间孔处的脊神经节，剥去包膜，清理周围组织，用游标卡尺测量第１胸髓上缘至第５腰髓下缘长度 There were 15 adult cadavers, of whom 6 were male and 9 were female, with a total of 30 sides. The thoracic organs were removed to their heads, neck and extremities respectively and dissected from the dorsal path until the vertebral arch was removed and the dural sac and vertebrae were exposed Between the holes, open the dural sac, and follow the back root until the spinal foramen at the intervertebral foramen, peel off the envelope, clean up the surrounding tissue, using the caliper to measure the upper edge of the first thoracic to the lower edge of the 5th lumbar