Breasts are not part of the internal or external female genitalia. Instead, they are secondary sex characteristics (physical characteristics other than genitals that distinguish males from females). In a physically mature woman, the breasts consist internally of fatty tissue and mammary (MAM-uh-ree), or milk, glands (I Figure 3.7). The glandular tissue in the breasts responds to sex hormones. During adolescence, both the fatty and the glandular tissues develop markedly. The amount of glandular tissue
Female Sexual Anatomy and Physiology
in the breasts varies little from woman to woman, despite differences in overall size. Consequently, the amount of milk produced after childbirth does not correlate with the size of the breasts. Variation in breast size is due primarily to the amount of fatty tissue distributed around the glands. It is common for one breast to be slightly larger than the other. Breasts show some size and texture variations at different phases of the menstrual cycle and when influenced by pregnancy, nursing, or birth control pills.
The nipple is in the center of the areola (ah-REE-oh-luh), the darker area of the external breast. The areola contains sebaceous (oil-producing) glands that help lubricate the nipples during breast-feeding. The openings of the mammary glands are in the nipples. Some nipples point outward from the breast, others are flush with the breast, and still others sink into the breast. The nipples become erect when small muscles at their base contract in response to touch, sexual arousal, or cold. For many women breast and nipple stimulation is an important source of pleasure and arousal during masturbation or sexual interaction. Some find that such stimulation helps build the sexual intensity that leads to orgasm; others enjoy it for its own sake. Other women find breast and nipple touching a neutral or unpleasant experience.
Breasts come in a multitude of sizes and shapes. One writer explained, "On real women, I’ve seen breasts as varied as faces: breasts shaped like tubes, breasts shaped like tears, breasts that flop down, breasts that point up, breasts that are dominated by thick, dark nipples and areola, breasts with nipples so small and pale they look airbrushed" (Angier, 1999, p. 128).
Breast size is a source of considerable preoccupation for many women and men in our society:
In talking with my friends about how we feel about our breasts, I discovered that not one of us feels really comfortable about how she looks. I’ve always been envious of women with large breasts because mine are small. But my friends with large breasts talk about feeling self-conscious about their breasts too. (Authors’ files)
I Figure 3.7 Cross-section front and side views of the female breast.
Surgeries to enlarge or reduce breasts reflect the dissatisfaction many women feel because their breasts do not fit the cultural ideal. In 2008 over 355,600 women in the United States had cosmetic breast implant surgery (American Society for Aesthetic Plastic Surgery, 2009). Since the late 1980s, increasing numbers of young women have been receiving breast augmentation (Farr, 2000). Many women who have cosmetic breast augmentation are pleased with the results. Others experience painful or disfiguring complications and poor results, such as loss of breast sensation, asymmetric breasts, and capsular contraction (scar tissue develops around the implant, which turns the soft capsule into a hard disk). One study found that 73% of women with breast implants experienced side effects, and 27% of women had their implants removed within 3 years because of infection, painful scar tissue, or a broken or leaking implant (about 15% rupture by 10 years) (Springen, 2003).