So far in this chapter, we have described the parts of the female sexual anatomy, but we have said relatively little about how these structures function. Because lubrication is a unique feature of the vagina, the process is explained here. Other physiological aspects of female arousal will be discussed in Chapter 6.
During sexual arousal, a clear, slippery fluid begins to appear on the vaginal mucosa within 10 to 30 seconds after effective physical or psychological stimulation begins. This lubrication is a result of vasocongestion, caused by the extensive network of blood vessels in the tissues surrounding the vagina engorging with blood. Clear fluid seeps from the congested tissues to the inside of the vaginal walls to form the characteristic slippery coating of the sexually aroused vagina.
Vaginal lubrication serves two functions. First, it enhances the possibility of conception by helping to alkalinize the normally acidic vaginal chemical balance. Vaginal pH level changes from 4.5 to 6.0-6.5 with sexual arousal (Meston, 2000). Sperm travel faster and survive longer in an alkaline environment than in an acidic one. (The seminal fluid of the male also helps alkalinize the vagina.) Second, vaginal lubrication can increase sexual enjoyment. During manual genital stimulation, the slippery wetness can increase the sensuousness and pleasure of touching. During oral-genital sex, some women’s partners enjoy the erotic scent and taste of the vaginal lubrication. During intercourse, vaginal lubrication makes the walls of the vagina slippery, which facilitates entry of the penis into the vagina. Lubrication also helps make the thrusting of intercourse pleasurable. Without adequate lubrication, entry of the penis and subsequent thrusting can be uncomfortable for the woman—and often for the man. Irritation and small tears of the vaginal tissue can result.
Insufficient vaginal lubrication can be remedied in several ways, depending on the source of the difficulty. Changing any anxiety-producing circumstances and engaging in effective stimulation are important. Saliva, lubricated condoms, or a nonirritating water-soluble jelly can be used to provide additional lubrication. Occasionally, hormone treatment is necessary. •