Читать книгу Ridley's The Vulva - Группа авторов - Страница 108

The vagina has an outer adventitial coat of fibroelastic tissue by which it is bound to the urethra and anchored to the pelvic walls by the pelvic ligaments. The intermediate coat of circular and longitudinal smooth muscle is intermingled with striated muscle from the pelvic floor. Between the muscular and inner epithelial layers is a layer of loose fibroelastic tissue in which there is an extensive network of venous channels. This venous network, with distension, changes the vaginal walls into erectile tissue and is the probable source of vaginal secretion during sexual intercourse. The inner aspect of the vagina is lined with non‐cornifying stratified squamous epithelium, the cells of which are heavily glycogenated. The vaginal surface of the cervix is covered with stratified squamous epithelium, while the cervical canal is lined by columnar epithelium in which there are numerous mucus‐secreting cells. The squamocolumnar junction may occur at the external os, but more often there is a transformation zone of variable extent situated around the external os.