This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
The space between the posterior commissure and the anus, about 3 cm. (1 1/4 in.) is the perineum (Fig. 465).
The labia minora divide anteriorly to form the prepuce above the clitoris and the fraenum on its lower surface. Posteriorly they fade away into a thin crescentic fold of mucous membrane called the fourchette. The space between the labia minora is the vestibule. The meatus or urethra is in the vestibule 2.5 cm. (1 in.) behind the clitoris. It is surrounded by a ring of mucous membrane and in introducing the catheter it can be recognized by the sense of touch and so localized. The openings of the para-urethral ducts are just below and to the outside of the meatus. The vulvovaginal glands (of Bartholin) empty on the inner side of the labia minora in the sulcus between them and the hymen. The openings of the ducts are just visible to the naked eye. The openings are about opposite the middle of the vaginal orifice and the ducts pass down and out to the glands, which are of the size of a bean and lie on each side of the lower end of the vagina.
Fig. 465. - External female genitals (vulva).
The hymen partly occludes the lower end of the vagina across its posterior portion. The carunculae hymenales are the remains of the ruptured hymen. The fossa navicularis is the space between the hymen and the fourchette.
The external genitals are well supplied with veins, and in pregnancy or pelvic growths they may become enlarged and varicose, especially over the labia majora. The fourchette and perineum frequently become ruptured in delivery, the tear, if complete, going into the rectum. The meatus is sometimes the seat of a papillo-an-giomatous growth called urethral caruncle. It is treated by removal. The vulvovaginal glands are the seat of cysts and abscesses. They appear as swellings alongside the posterior portion of the vaginal opening. The former are to be carefully and completely excised and the latter opened and packed. The vulvar slit is anteroposterior, the vagina forms a transverse slit and the hymen is placed at the point of transition. In making a vaginal examination (dorsal decubitus) the index finger is to be held vertically until the vestibule is entered. It then is passed horizontally into the vagina and turned palmar surface upward to recognize the cervix entering the anterior vaginal wall. Firm pressure with the other hand to depress the external parts is necessary to reach the posterior fornix and Douglas's pouch.
Fig,. 466. - Hernia of the bladder (cystocele) and of the rectum (rectocele).
As a result of the relaxation following childbirth the bladder may prolapse through the vaginal orifice. When the uterus prolapses it also drags the bladder down with it. It is to be recognized by passing a sound through the urethra into it. It is treated by excising the mucous membrane covering the cystocele and sewing the sides of the wound together, thus crowding the mucous lining of the bladder up into position (Fig. 466).
The rectum prolapses at the posterior wall of the vagina the same as the bladder does anteriorly and it is treated in a similar manner.