Vagina

The vagina is a fibromuscular canal that forms part of the female internal reproductive tract, running from the vulva to the cervix. In adults it is typically about 7 to 10 centimeters long, but length varies. It serves as a passage for sexual intercourse, menstrual blood, and childbirth, and it accommodates natural lubrication during sexual arousal.

The vaginal wall consists of three layers: an inner mucosal lining, a muscular middle layer, and an connective tissue outer layer. The mucosa is lined by non-keratinized stratified squamous epithelium with folds called rugae that allow expansion. The canal lies anterior to the rectum and behind the urethra and bladder.

The vaginal environment is normally acidic thanks to a Lactobacillus-dominated microbiota, which produces lactic acid and helps protect against infections. Normal secretions from the vaginal and cervical mucosa provide lubrication. Bartholin’s glands near the vaginal opening contribute additional lubrication.

Functions extend beyond intercourse: the vagina acts as a channel for menstrual flow and, during childbirth, forms the birth canal through which a baby passes. It is also part of the broader female reproductive system, interacting with the uterus and cervix.

Health considerations include infections such as bacterial vaginosis and candidiasis, as well as hormonal changes that can cause dryness or atrophy after menopause. Douching is generally discouraged because it can disrupt the natural microbiota. Regular gynecologic care and safe-sex practices support vaginal health; Pap tests assess the cervix, not the vagina itself.