In common speech, the term “vagina” is often used improperly to refer to the female genitals generally or the vulva; strictly speaking the vagina is a specific internal structure and the vulva is the exterior genitalia only. Calling the vulva the vagina is akin to calling the mouth the throat. The appearance of the vulva and the size of the various parts varies a great deal from one woman to another, and it is common for the left and right sides to not “match” exactly in an individual woman
The vagina can perform the following tasks:
- Admit the penis of the male for sexual intercourse and ultimately the introduction of sperm for the fertilization of ova.
- Provide sexual pleasure to a woman (although vaginal orgasms are rarer than clitoral orgasms).
- During live birth, provide the route to deliver the fetus from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal.
- Provide a path for menstraul fluids to leave the body.
The vagina is an elastic muscular tube about 4 inches (100 mm) long and 1 inch (25 mm) in diameter that connects the vulva at the outside to the cervix of the uteras at the inside. If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of approximately 90 degrees with the uterus. The vaginal opening is at the back end of the vulva, behind the opening of the uretha. The inside of the vagina is usually pink.
Length, width and shape of the vagina vary greatly. Vaginal lubrication is provided by glands near the vaginal opening and the cervix. There is some debate on whether or not the vaginal lining (epithelium) provides any type of lubrication.
Slightly below and to the left and right of the vaginal opening are two Bartholin glands; when the woman is sexually aroused, they produce a lubricating substance that makes sexual penetration easier. If this lubrication is insufficient, artificial lubrication may be used to facilitate sexual intercourse. If excessive lubrication is experienced, there are non-medical and medical options available to decrease some of the vaginal moisture.
The cervix has a constant downward flow of mucous to prevent bacteria from entering the uterus and continually cleanses the vagina. This mucous is affected by the hormone changes (ie. menstual cycle, birth contol pills).
Vaginal mucous tissue (epithelium) is a protective tissue that covers the wall of the vagina and is rather strong. The thickness of this tissue is determined by the balance of the sex hormones. This balance changes during the menstrual cycle, during pregnancy and with age. In young girls and older women, the mucous tissue is only a few cell layers thick, therefore these women are quite vulnerable and the delicate balance of micro-organisms in the vagina can be easily disturbed.
The vaginal environment is a complex ecosystem that consists of a great many ‘friendly’ micro-organisms (bacteria and yeast) that live together in the vagina. Together these micro-organisms are called the ‘vaginal flora’. If this balance is upset, yeast can overgrow causing symptoms that often indicate a vaginal infection. (ie. Yeast infection). It is important to note that the vagina usually has an acidic environment (low pH) to prevent overgrowth of the normal yeast present in the vagina. This acidity is largely determined by Lactobacilli, one of the ‘friendly’ bacteria found in the vagina. The ecosystem is hormonally and pH dependent & thus varies throughout the menstrual cycle.