Shafik A
Faculty of Medicine, Cairo University, Egypt.
Int Urogynecol J Pelvic Floor Dysfunct. 2000 Dec;11(6):361-76. doi: 10.1007/pl00004028.
This paper reviews the role of the levator ani muscle (LAM) in evacuation, sexual performance and pelvic floor disorders. The LAM fixes the vesical neck, anorectal junction and vaginal fornices to the side wall of the pelvis by means of the suspensory sling and hiatal ligament. On contraction it shares in the mechanism of evacuation (urination, defecation). During the sexual act vaginal distension by the erect penis evokes the vaginolevator and vaginopuborectalis reflexes, with a resulting LAM contraction. The LAM also contracts upon stimulation of the clitoris or cervix uteri, an action mediated through clitoromotor and cervicomotor reflexes. LAM contraction leads to upper vagina ballooning, which acts as receptacle for semen collection, to uterine elevation and straightening and to elongation and narrowing of the vagina. These actions enhance the sexual response and prepare the uterus and vagina for the reproductive process. During ejaculation LAM contraction facilitates semen ejection. Levator subluxation and sagging leads to levator dysfunction syndrome, which may present as pudendal canal syndrome.
本文综述了肛提肌（LAM）在排空、性功能及盆底功能障碍中的作用。肛提肌通过悬吊吊带和裂孔韧带将膀胱颈、直肠肛门交界处及阴道穹隆固定于骨盆侧壁。收缩时，它参与排空机制（排尿、排便）。在性行为中，勃起的阴茎使阴道扩张会引发阴道肛提肌和阴道耻骨直肠肌反射，导致肛提肌收缩。刺激阴蒂或子宫颈时，肛提肌也会收缩，此动作通过阴蒂运动反射和子宫颈运动反射介导。肛提肌收缩会导致阴道上段膨胀，起到收集精液的容器作用，使子宫抬高并伸直，以及使阴道伸长和变窄。这些动作增强性反应，并为生殖过程准备好子宫和阴道。射精时，肛提肌收缩有助于精液射出。肛提肌半脱位和下垂会导致肛提肌功能障碍综合征，可能表现为阴部管综合征。
