Sex For Dummies. Dr. Ruth K. Westheimer
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any less clean than its male counterpart. But, if you still feel uncomfortable about this region, you have an easy solution.
The hymen: Symbol of virginity
The hymen is the membrane that covers the entrance to the vagina. When intact, the hymen was once considered the traditional proof of a woman’s virginity. Her status as a virgin was verified by the bleeding that often occurs when the hymen is first penetrated (see Chapter 10).
In some cultures, the mother of the bride would actually display the bloody sheets after the wedding night to show how pure her daughter had been before her marriage. And if by some chance the daughter had been slightly impure, some chicken’s blood would do — especially because DNA testing hadn’t been invented yet.
Today, however, many women break this membrane accidentally before their first attempt at sexual intercourse, either by inserting a tampon or while performing vigorous activities, such as bicycle riding or horseback riding. In the vast majority of cases, even an intact hymen has perforations so menstrual blood can pass through, but some women are born without these perforations and a doctor must pierce the hymen. (By the way, the fact that a woman has broken her hymen before she’s had sexual intercourse doesn’t change her status as a virgin. Traditionally, only through actual intercourse with a man could she change that standing, as that was the only way to risk pregnancy. In today’s world, where people engage in sex in so many ways, the entire concept of virginity remains quite fluid.)
The vagina: The main thoroughfare
What makes women different from men is that much of our sexual apparatus is on the inside — most notably, the vagina. The vagina itself is a hollow, muscular tube that extends from the external opening at the vestibule all the way to the cervix, which is the entrance to the uterus. (The cervix and uterus have their own sections in this chapter.)
An adult woman’s vagina is about 3 to 4 inches long and extremely flexible. During intercourse, the vagina stretches to accommodate the penis. When a woman gives birth, the vagina stretches even more, becoming part of the birth canal through which the baby passes on its way into the world. When a vagina has nothing in it, it collapses like an empty balloon.
Supporting the structure
The walls of the vagina have several layers (see Figure 3-3). The first is the mucosa, or vaginal lining. The mucosa is very thick and has many folds. It responds to the woman’s hormonal changes by secreting various types of fluids. Under the mucosa are a muscular layer and a layer of connective tissue (the adventitia) that are rich in blood.
Illustration by Kathryn Born
FIGURE 3-3: Lubricating fluids and an enveloping fullness come from the vaginal walls to enhance sexual pleasure.
Beneath the vagina, on the pelvic floor, are other muscles that are responsible for keeping the vagina elevated, tight, and firm. Women can do Kegel exercises, which I talk about in Chapter 12, to help tone these muscles.
Speaking of working out, sometimes when a woman exercises or has intercourse, the action can force air into the vagina. When the woman changes position, the air goes back out, producing a sound as if she were passing gas. This occurrence is common and shouldn’t cause any embarrassment.
Lubricating the vagina
During sexual excitement, a woman experiences several physical changes:
The vaginal lips and clitoris swell.
The nipples on her breasts become erect.
The vaginal walls fill with blood in a process called vasocongestion, which is similar to the way blood flows into the penis during erection.
The vagina becomes lubricated, or slippery, by the passage of fluids through the vaginal walls. This lubrication isn’t manufactured by a gland, but occurs when fluid filters into the vagina from blood vessels surrounding it. The vasocongestion causes increased pressure that, in turn, causes the fluid within the blood serum to be pushed through the tissues of the vaginal wall.
This fluid has another function besides making it easier for the penis to slide in and out of the vagina. It also changes the chemical nature of the vagina, making it more alkaline and less acidic, an environment that proves more hospitable to sperm.
In most mammals, the female doesn’t provide any lubrication; instead, the male secretes the lubricant, similar to what the Cowper’s gland in human males produces, but in much greater quantities. Researchers have noted that, when males of certain species, such as horses, get aroused, a steady stream of this fluid flows out of the penis.
Changes through your life
The vagina goes through several changes in a woman’s life.
Before puberty, the vaginal walls are thinner and the vaginal tube is smaller, which is one reason that so much damage can be done to a young girl who is sexually abused.
During puberty, the vagina grows, and hormones cause other changes to take place. The vagina becomes elevated, firm, and erect when a woman becomes sexually aroused.
After menopause (which I explain very soon, so be patient), a woman’s hormonal levels go down, and the vaginal tissue becomes more fragile and less elastic. A woman’s natural lubrication also declines at this time. Luckily, you have ways to treat all these problems so that they don’t affect good sexual functioning.
At your cervix
At the top of the vagina is the cervix, which is the entrance to the uterus. The cervix is actually the lower portion of the uterus, and it protrudes approximately one-third of an inch into the vagina. The cervix produces a special mucus that changes according to the woman’s menstrual cycle — the monthly process of releasing eggs in preparation for possible pregnancy (see “The ‘Men’ Words: Menstruation and Menopause,” later in this chapter).