Читать книгу Ridley's The Vulva - Группа авторов - Страница 95

The pudendal nerve enters the ischiorectal fossa, close to the tip of the ischial spine on the medial side of the pudendal artery. Running anteriorly on the lateral wall of the ischiorectal fossa, it gives rise to the inferior haemorrhoidal nerve, which arches over the roof of the fossa to reach the midline, where it supplies the terminal part of the anal canal and the perianal skin. The pudendal nerve then divides into the perineal branch, which supplies the rest of the perineal skin, and the dorsal nerve of the clitoris, which supplies the anterior labia minora and the glans of the clitoris.

The inferior haemorrhoidal branch of the pudendal nerve supplies the deep and subcutaneous parts of the external anal sphincter. The perineal branch supplies the muscles of the urogenital triangle as well as the anterior part of the levator ani muscle and the urethral sphincter. The remainder of the levator ani muscle and the superficial part of the external anal sphincter are supplied by the perineal branch of the fourth sacral nerve. Damage to the pudendal nerves may cause loss of muscle tone in the pelvic floor and can be associated with problems of incontinence.