直肠的弯曲及直肠壶腹 Rectum and Anal canal Rectosigmoid junction Supenor rectal valve iddle rectal valve Inferior rectal valre 11-13 Anal columns (of Morgagni) Muscularis mucosae Circular muscle layer ret Longitudinal muscle layer Rectal fascia Levator ani muscle Anal sinus Anorectal (pectinate, or dentate) line Intemal rect plexus in submucous space Intemal sphincter muscle Surgica Deep extemal sphincter muscle anal canal Conjoined longitudinal muscle Anat 一2:53 atomical Superficial extemal sphincter muscle Anal valve I canal Anal crypt Anal verge ≈ al glands Sweat glands -Transverse fibrous septum and hairs in Intermuscular groove (white line of Hilton) Musculus submucosa ani perianal skin Extemal rectal venous plexus in perianal sPace Penanal space Corrugator cutis ani muscle Subcutaneous extemal sphincter muscl O CIBA-GEIGY直肠的弯曲及直肠壶腹