Breasts, or mammary glands, are modified sweat glands that produce milk to nourish a newborn child. The breasts contain fatty tissue and milk-producing glands and are capped by a nipple surrounded by a round, pigmented area called the areola (ah-REE — oh-luh). Each breast contains between 15 and 20 lobes, made up of a number of compartments that contain alveoli, the milk-secreting glands. Alveoli empty into secondary tubules, which in turn pass the milk into the mammary ducts and then into the lactiferous sinuses, where the milk is stored until the lactiferous ducts release it from the nipple (Figure 4.4). When lactation begins, infant suckling stimulates the posterior pituitary gland to release prolactin, which signals milk synthesis, and oxytocin, which allows the milk to be ejected.
Most people see the breasts as an erogenous zone and include stimulation of the breasts in sexual arousal and masturbation. Some women can even experience orgasm from breast and nipple stimulation alone. But many women in American society are uncomfortable about the size and shape of their breasts. Because breasts are a constant source of attention in our society and are considered an important part of a woman’s attractiveness, women may worry that their breasts are unattractive, too small, or too large. Yet the ideal breast differs in other cultures. For example, large breasts are valued in the United States, and so over 80% of breast surgeries are performed to increase the size of the bust. In France, however, the majority of surgical alterations of the breasts are to decrease their size! Although there has been a cultural emphasis on larger breasts in
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I nipple A pigmented, wrinkled protuberance on the surface of the breast that contains ducts for the release of milk. |
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areola The pigmented ring around the nipple of the breast. |
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lactation The collective name for milk creation, secretion, and ejection from the nipple. |
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prolactin A hormone secreted by the pituitary gland that initiates and maintains milk secretion. |
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oxytocin A hormone secreted by the hypothalamus that stimulates contraction of both the uterus for delivery of the newborn and the mammary gland ducts for lactation. |
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the United States, there has been a significant decrease in the chest size preferred by women overall (Tantleff-Dunn, 2001).
Other Erogenous Zones
There are many other erogenous zones on the body that can be considered part of a woman’s sexual organ system. In fact, the largest sexual organ of all is the skin, and there is no part of it that cannot be aroused if caressed in the right way at the right time during lovemaking. Some of the more common erogenous areas include the lips or the ears, but others, such as the back of the knee, the armpit, or the base of the neck, for example, may be stimulating to certain people. Some people find stimulation of the anus, or anal intercourse, extremely erotic, whereas others do not. Of course, the most important sexual organ is one that you can stimulate only indirectly—the brain.