DeLancey J O, Starr R A
Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor 48109-0718.
J Reprod Med. 1990 Aug;35(8):765-71.
The proximal urethra is a mobile structure, and voluntary control of its position is an integral part of the initiation of urination and continence. This paper describes the histology of the vagina's attachment to the medial portion of the levator ani muscles, which, because of the intimate attachment of the vagina and urethra, is responsible, in part, for control of the urethral position. A histologic examination of 1,500 serial microscopic slides from eight women, dissection of four bodies and study of whole pelvis cross-sections from two cadavers were performed. Smooth muscle, collagen and elastin fibers of the vaginal wall and paraurethral tissues directly interdigitate with the muscle fibers of the most medial portion of the levator ani, in the region of the proximal urethra. This strong connection lies at a level just below the entry of the urethra into the bladder and extends downward to the level of the perineal membrane (urogenital diaphragm) in an area corresponding to the mobile portion of the urethra. The inseparable nature of the vagina and urethra in this region makes it possible for the connection of the levator ani to the vagina to control the proximal urethral position. These observations suggest a specific role of the medial levator ani muscle in controlling vesical neck position and open the question of the specific part played by this arrangement in voiding and continence relative to other factors known to influence lower urinary tract function.
近端尿道是一个可移动的结构，对其位置的自主控制是排尿起始和控尿的一个组成部分。本文描述了阴道与肛提肌内侧部分附着处的组织学情况，由于阴道和尿道紧密相连，这部分结构在一定程度上负责控制尿道位置。对8名女性的1500张连续显微切片进行了组织学检查，解剖了4具尸体，并研究了2具尸体的全盆腔横截面。在近端尿道区域，阴道壁和尿道旁组织的平滑肌、胶原纤维和弹性纤维与肛提肌最内侧部分的肌纤维直接相互交错。这种紧密连接位于尿道进入膀胱的入口下方，向下延伸至会阴膜（尿生殖膈）水平，对应于尿道的可移动部分。该区域阴道和尿道不可分割的特性使得肛提肌与阴道的连接能够控制近端尿道的位置。这些观察结果提示了肛提肌内侧部分在控制膀胱颈位置方面的特定作用，并引发了关于这种结构在排尿和控尿中相对于其他已知影响下尿路功能的因素所起特定作用的问题。
