The vagina is an elastic, yet muscular canal that is approximately 9 to 10 centimeters in length. The upper part of the vagina connects to the cervix, which opens into the uterus, and the lower part opens to the outside of the body. It lies between the urethra (which connects to the bladder) and the rectum.
During sexual intercourse, the vagina lengthens, widens and engorges with blood as it prepares to accept the penis. Additionally, the vagina serves as a passageway for cervical mucus, menstrual fluid and other secretions out of the body. During childbirth, the baby is pushed from the uterus out of the body, also through the vaginal canal.
It is important to know that the vagina is self-cleaning. Many women feel the need to douche or clean the vagina using sprays or deodorants. Not only is that not necessary, but it can actually harm your vaginal health.
The vagina maintains this self-cleaning property in a few ways.
It's slightly acidic environment prevents most bacteria from living in it. Douching or cleaning the vagina can alter the pH, making it more susceptible to bacterial or fungal infections.
In addition, the tissue lining the vagina is thickened after puberty and until menopause, which also helps prevents bacterial colonization.
The bacteria Lactobacillus acidophilus is normally found in the vaginal tissue, and it helps to stabilize the pH at its natural acidic level. Anything that disturbs these bacteria (like antibiotics) can also increase your risk for vaginal infection. Eating yogurt with natural cultures or taking a L. acidophilus supplement during antibiotic usage may be helpful in preventing an infection. Of course, talk to your doctor to make sure that this is appropriate for you.