一、直肠肛管的界限和构成1.直肠是结肠的延续,为大肠的终段,上接乙状结肠,下连肛管,成人的长度约为12～15cm,起自第3骶椎平面,其走行方向开始段通常与正中线相吻合,以后紧依骶骨和尾骨的曲线向下。在其下段有提肛肌的耻骨直肠部分与其两侧接触,该部在男性 First, the limits and composition of the rectum anal canal 1. The rectum is the continuation of the colon, the large intestine of the final section, the next sigmoid colon, the next even the anal canal, adult length of about 12 ~ 15cm, starting from the 3rd sacral plane, its The beginning of the walking direction usually coincides with the median line, and the curve following the sacrum and coccyx closely follows downward. In the lower part of the levator ani muscle puborectalis part of its contact with both sides, the Ministry of men