Vaginal lining. Coloured scanning electron micrograph (SEM) of the lining of the vagina, showing the characteristic flat, scale-like squamous cells. The vagina is a muscular tube leading from the uterus to the exterior of the body (vulva) in female placental mammals. It serves as a passageway for receiving sperm and discharging menstrual flow, and expands greatly to allow the passage of a baby during childbirth. The surface of the vagina is covered in a stratified squamous epithelial layer. Magnification x500 when printed 10 centimetres wide