Chapter 1 & 3 Female Sexual Anatomy Physiology and Response Paper

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For both questions, you are required to thoroughly answer the reflection questions below and clearly connect the information to the learning objectives. The summaries should show critical analysis and synthesis of the information in a way that demonstrates good understanding of the material presented. Each question should be 4-5 paragraphs (containing a minimum of 4-6 sentences each) in length. So around 10 paragraphs total.

Question #1:

Reading Chapter 1 (pp. 39 - pp. 65) of the book that I attached in the following PDF file, complete the Questions for Discussion on page 27:

1. At what age do you believe a young person should be given a smartphone? What, if any, type of education should accompany it?

2. To what extent do you think your peers are influenced by the media? To what extent are you?

3. While growing up, what sexual behaviors did you consider to be normal? Abnormal? How have these views changed now that you are older?

Question #2

Read the Chapter 3 of the textbook (pp.68 - pp.103) and answer the 3 Questions for Discussion (pp. 103) found in Chapter 3 of the textbook related to sex research.


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yar35317_ch03_068-104.indd Page 68 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles chapter 3 Female Sexual Anatomy, Physiology, and Response 68 MAIN TOPICS Female Sex Organs: What Are They For? 69 Female Sexual Physiology 81 Female Sexual Response 90 yar35317_ch03_068-104.indd Page 69 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles “I identify with the passion [of women], the strength, the calmness, and the flexibility of being a woman. To me being a woman is like being the ocean. The ocean is a powerful thing, even at its calmest moments. It is a beauty that commands respect. It can challenge even the strongest men, and it gives birth to the smallest creatures. It is a provider, and an inspiration; this is a woman and this is what I am.” —20-year-old female “The more I think about things that annoy me about being a woman, the more I realize that those annoyances are what make it so special. When I get my period, it isn’t just a ‘monthly curse’; it is a reminder that I can have children.” —19-year-old female “When I started my period, my father kept a bit of a distance. How could I forget [that day]? The entire family was at my aunt’s house, and no one had pads. You would think among 67 or so people one female would have a pad. I remember crying and my grandmother asking me what was wrong. After I told Student her, she began to Voices laugh and said it was a natural cycle. I knew this from sixth-grade sexuality education class, but I still didn’t want it. I was finally a woman.” —19-year-old female “I think I am a good sexual partner and enjoy pleasing a woman. I especially love the foreplay that occurs between two people because it gets the body more excited than just going at it. I can go on forever with foreplay because I get to explore my partner’s body, whether it is with my hands, lips, or tongue.” —25-year-old male A lthough women and men are similar in many more ways than they are different, we tend to focus on the differences rather than the similarities. Various cultures hold diverse ideas about exactly what it means to be female or male, but virtually the only differences that are consistent are actual physical differences, most of which relate to sexual structure and function. In this chapter and the following one, we discuss both the similarities and the differences in the anatomy (body structures), physiology (body functions), and sexual response of females and males. This chapter introduces the sexual structures and functions of women’s bodies, including hormones and the menstrual cycle. We also look at models of sexual arousal and response, the relationship of these to women’s experiences of sex, and the role of orgasm. In Chapter 4, we discuss male anatomy and physiology, and in Chapter 5, we move beyond biology to look at gender and the meanings we ascribe to being female and male. • Female Sex Organs: What Are They For? Anatomically speaking, all embryos are female when their reproductive structures begin to develop (see Figure 3.1). If it does not receive certain genetic and hormonal signals, the fetus will continue to develop as a female. In humans and most other mammals, the female, in addition to providing half the genetic instructions for the offspring, provides the environment in which it can develop until it becomes capable of surviving as a separate entity. She also nourishes the offspring, both during gestation (the period of carrying the young in the uterus) via the placenta and following birth via the breasts through lactation (milk production). In spite of what we do know, we haven’t yet mapped all of the basic body parts of women, especially as they relate to the microprocesses of sexual Female Sex Organs: What Are They For? • 69 yar35317_ch03_068-104.indd Page 70 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Undifferentiated Stage Prior to 6th Week Genital tubercle Genital groove Urogenital fold Female Labioscrotal swelling Anus 7th– 8th Week Male Glans (clitoris) Glans (penis) Inner labial fold Urogenital fold Labial swelling Vulval groove Urethral groove Scrotal swelling Anus Anus Female 12th Week Male Penis Clitoris Labia minora Opening of urethra Opening of vagina Urethral closure Scrotum Labia majora • FIGURE 3.1 Embryonic-Fetal Differentiation of the External Reproductive Organs. Female and male reproductive organs are formed from the same embryonic tissues. An embryo’s external genitals are female in appearance until certain genetic and hormonal instructions signal the development of male organs. Without such instructions, the genitals continue to develop as female. 70 • Chapter 3 response. Such issues as the function of the G-spot, the role of orgasm, and the placement of the many nerves that spider through the pelvic cavity still are not completely understood. Add to these puzzles the types, causes, and treatments of sexual function problems and one can quickly see that the science of sexual response is still emerging. Clearly, the female sex organs serve a reproductive function. But they perform other functions as well. Significant to nearly all women are the sexual parts that bring them pleasure; they may also serve to attract potential sexual partners. Because of the mutual pleasure partners give each other, we can see that sexual structures also serve an important role in human relationships. People demonstrate their affection for one another by sharing sexual pleasure and generally form enduring partnerships at least partially on the basis of mutual sexual sharing. Let’s look at the features of human female anatomy and physiology that provide pleasure to women and their partners and that enable women to conceive and give birth. Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 71 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Symphysis pubis Suspensory ligament of clitoris Corpora cavernosa of clitoris Glans clitoris Prepuce of clitoris Crura of clitoris Frenulum of clitoris Inner lips External urethral opening Remnants of hymen Vaginal opening Ischiocavernosus muscle Vestibular bulb Greater vestibular gland and its orifice External anal sphincter muscle Vestibule of vagina; Frenulum of inner lips Anus • FIGURE 3.2 External Female Structures (Vulva) External Structures (the Vulva) The sexual and reproductive organs of both men and women are usually called genitals, or genitalia, from the Latin genere, “to beget.” The external female genitals are the mons pubis, the clitoris, the labia majora, and the labia minora, collectively known as the vulva (see Figure 3.2). (People often use the word “vagina” when they are actually referring to the vulva. The vagina is an internal structure.) The Mons Pubis The mons pubis (pubic mound), or mons veneris (mound of Venus), is a pad of fatty tissue that covers the area of the pubic bone about 6 inches below the navel. Beginning in puberty, the mons is covered with pubic hair. Because there is a rich supply of nerve endings in the mons, caressing it can produce pleasure in most women. The current practice of trimming and shaving pubic hair has become one barometer of fashion (Ramsey, Sweeney, Fraser, & Oades, 2009). Over the past few years, it has become commonplace in both sexes and for similar reasons: aesthetic and psychosexual. Its acceptance and practice among women has been revealed in a recent publication (Herbenick, Schick, Reece, Sanders, & Fortenberry, 2010) which notes that a diverse range of pubic hair–grooming practices appears to be an important component of sexual expression and People will insist on treating the mons “ veneris as though it were Mount Everest. —Aldous Huxley (1894–1963) Female Sex Organs: What Are They For? • 71 yar35317_ch03_068-104.indd Page 72 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles participation in sexual activity. Findings were that pubic hair styles are diverse and that it is more common than not for women to have at least some pubic hair on their genitals. The authors of the study found that women’s total removal of their pubic hair was associated with being young, being partnered, having looked closely at one’s own genitals, cunnilingus, positive genital self-image, and sexual function. Implicated in the shift in cultural attitudes regarding pubic hair is Internetbased pornography, where removal has become the “norm.” This practice, however, is not new; many societies have decorated and sculpted their pubic hair for centuries, while others have removed the hair to avoid body lice. Many anecdotal reports on the removal of pubic hair highlight increased genital sensitivity and increased partner satisfaction. From a public health perspective, body hair removal may be a risk factor for folliculitis (the inflammation of one or more hair follicles) (Trager, 2006). On the other hand, a significant drop has been found in the number of cases of pubic lice (Armstrong & Wilson, 2006). If a woman chooses to shave, wax, or have her genitals pierced, she should use only clean tools and exercise caution, since this is obviously a sensitive area. Really that little dealybob is too far from the hole. It should be built “ away right in. —Loretta Lynn (1935–) Artwork often imitates anatomy, as can be seen in this painting titled Black Iris (Georgia O’Keeffe, 1887–1986). The Clitoris The clitoris (KLIH-tuh-rus) is considered the center of sexual arousal. It contains a high concentration of sensory nerve endings and is exquisitely sensitive to stimulation, especially at the tip of its shaft, the glans clitoris. A fold of skin called the clitoral hood covers the glans when the clitoris is not engorged. Although the clitoris is structurally analogous to the penis (it is formed from the same embryonic tissue), its sole function is sexual arousal. (The penis serves the additional functions of urine excretion and semen ejaculation.) The clitoris is a far more extensive structure than its visible part, the glans, would suggest (Bancroft, 2009). The shaft of the clitoris is both an external and an internal structure. The external portion is about 1 inch long and a quarter inch wide. Internally, the shaft is divided into two branches called crura (KROO-ra; singular, crus), each of which is about 3.5 inches long, which are the tips of erectile tissue that attach to the pelvic bones. The crura contain two corpora cavernosa (KOR-por-a kav-er-NO-sa), hollow chambers that fill with blood and swell during arousal. The hidden erectile tissue of the clitoris plus the surrounding muscle tissue all contribute to muscle spasms associated with orgasm. When stimulated, the clitoris enlarges initially and then retracts beneath the hood just before and during orgasm. With repeated orgasms, it follows the same pattern of engorgement and retraction, although its swellings may not be as pronounced after the initial orgasm. The role of the clitoris in producing an orgasm is discussed later in the chapter. The Labia Majora and Labia Minora The labia majora (LAY-be- a maJOR-a) (major lips) are two folds of spongy flesh extending from the mons pubis and enclosing the labia minora, clitoris, urethral opening, and vaginal entrance. The labia minora (minor lips) are smaller folds within the labia majora that meet above the clitoris to form the clitoral hood. The labia minora also enclose the urethral and vaginal openings. They are smooth and hairless and vary quite a bit in appearance from woman to woman. Another rich source of sexual sensation, the labia are sensitive to the touch and swell during sexual arousal, doubling or tripling in size and changing in color 72 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 73 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles from flesh-toned to a deeper hue. The area enclosed by the labia minora is referred to as the vestibule. During sexual arousal, the clitoris becomes erect, the labia minora widen, and the vestibule (vaginal opening) becomes visible. Within the vestibule, on either side of the vaginal opening, are two small ducts from the Bartholin’s glands (or vestibular glands), which secrete a small amount of moisture during sexual arousal. Internal Structures The internal female sexual anatomy and reproductive organs include the vagina; the uterus and its lower opening, the cervix; the ovaries; and the fallopian tubes. (Figure 3.3 provides illustrations of the front and side views of the female internal sexual anatomy.) • FIGURE 3.3 Internal Female Sexual Structures Fallopian tube Fimbriae Ovary Uterus Cervix Bladder Rectum Pubic bone Vagina Approximate location of the G-spot Urethra Crura Clitoris (glans) Anus Hymen Urinary opening Vaginal opening (introitus) Labia majora Labia minora (a) Side view Fallopian tubes Ovaries Fimbriae Uterus Endometrium Cervix Os (b) Front view Vagina Female Sex Organs: What Are They For? • 73 yar35317_ch03_068-104.indd Page 74 6/25/12 7:25 PM user-f502 The external female genitalia (vulva) can assume many different colors, shapes, and structures. 74 • Chapter 3 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles The Vagina The vagina (va-JI-na), from the Latin word for sheath, is a flexible, muscular structure that extends 3–5 inches back and upward from the vaginal opening. It is the birth canal through which an infant is born, allows menstrual flow to pass from the uterus, and encompasses the penis or other object during sexual expression. In the unaroused state, the walls of the vagina are relaxed and collapsed together, but during sexual arousal, the inner two thirds of the vagina expand while pressure from engorgement causes the many small blood vessels that lie in the vaginal wall to produce lubrication. In response to sexual stimulation, lubrication can occur within 10–30 seconds. The majority of sensory nerve endings are concentrated in the lower third of the vagina, or the introitus (in-TROY-tus). This part of the vagina is the most sensitive to erotic pressure and touch. In contrast, the inner two thirds of the vagina have virtually no nerve endings, which make it likely that a woman cannot feel a tampon when it is inserted deep in the vagina. Although the vaginal walls are generally moist, the wetness of a woman’s vagina can vary by woman, by the stage of her menstrual cycle, and after childbirth or at menopause. Lubrication also increases substantially with sexual excitement. This lubrication serves several purposes. First, it increases the possibility of conception by alkalinizing the normally acidic chemical balance in the vagina, thus making it more hospitable to sperm, which die faster in acid environments. Second, it can make penetration more pleasurable by reducing friction in the vaginal walls. Third, the lubrication helps prevent small tears in the vagina which, if they occur, can make the vagina more vulnerable to contracting HIV. Prior to first intercourse or other form of penetration, the introitus is partially covered by a thin membrane containing a relatively large number of blood vessels, the hymen (named for the Roman god of marriage). The hymen typically has one or several perforations, allowing menstrual blood and mucous secretions to flow out of the vagina (and generally allowing for tampon insertion). In many cultures, it is (or was) important for a woman’s hymen to be intact on her wedding day. Blood on the nuptial bedsheets is taken as proof of her virginity. The stretching or tearing of the hymen may produce some pain or discomfort and Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 75 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles practically speaking Performing a Gynecological Self-Examination While reading this material, female readers may wish to examine their own genitals and discover their unique features. In a space that is comfortable for you, take time to look at your vulva, or outer genitals, using a mirror and a good light. The large, soft folds of skin with hair on them are the outer lips, or labia majora. The color, texture, and pattern of this hair vary widely among women. Inside the outer lips are the inner lips, or labia minora. These have no hair and vary in size from small to large and protruding. They extend from below the vagina up toward the pubic bone, where they form a hood over the clitoris. The glans may not be visible under the clitoral hood, but it can be seen if a woman separates the labia minor and retracts the hood. The size and shape of the clitoris, as well as the hood, also vary widely among women. These variations have nothing to do with a woman’s ability to respond sexually. You may also find some cheesy white matter under the hood. This is called smegma and is normal. Below the clitoris is a smooth area and then a small hole. This is the urinary opening, also called the meatus. Below the urinary opening is the vaginal opening, which is surrounded by rings of tissue. One of these, which you may or may not be able to see, is the hymen. Just inside the vagina, on both sides, are the Bartholin’s glands. These may secrete a small amount of mucus during sexual excitement, but little else of their function is known. If they are infected, they will be swollen, but otherwise you won’t notice them. The smooth area between your vagina and anus is called the perineum. You can also examine your inner genitals, using a speculum, flashlight, and mirror. A speculum is an instrument used to hold the vaginal walls apart, allowing a clear view of the vagina and cervix. You should be able to obtain a speculum and information about doing an internal exam from a clinic that specializes in women’s health or family planning. It is a good idea to observe and become aware of what your normal vaginal discharges look and feel like. Colors vary from white to gray, and secretions change in consistency from thick Examining your genitals can be an enlightening and useful practice that can provide you with information about the health of your body. to thin and clear (similar to egg white that can be stretched between the fingers) over the course of the menstrual cycle. Distinct changes or odors, along with burning, bleeding between menstrual cycles, pain in the pelvic region, itching, or rashes, should be reported to a physician. By inserting one or two fingers into the vagina and reaching deep into the canal, it is possible to feel the cervix, or tip of the uterus. In contrast to the soft vaginal walls, the cervix feels like the end of a nose: firm and round. In doing a vaginal self-exam, you may initially experience some fear or uneasiness about touching your body. In the long run, however, your patience and persistence will pay off in increased body awareness and a heightened sense of personal health. Once you’re familiar with the normal appearance of your outer genitals, you can check for any changes, especially unusual rashes, soreness, warts, or parasites, such as pubic lice, or “crabs.” possibly some bleeding. Usually, the partner has little trouble inserting the penis or other object through the hymen if he or she is gentle and there is adequate lubrication. Prior to first intercourse, the hymen may be stretched or ruptured by tampon insertion, by the woman’s self-manipulation, by a partner during noncoital sexual activity, by accident, or by a health-care provider conducting a routine pelvic examination. Hymenoplasty, a controversial procedure that reattaches the hymen to the vagina, is now sought by some women, particularly in Muslim countries where traditionalists place a high value on a woman’s virginity, to create the illusion that they are still virgins. Hymen repair, also referred to as “revirgination,” may also be performed for women who have been abused Female Sex Organs: What Are They For? • 75 yar35317_ch03_068-104.indd Page 76 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles • FIGURE 3.4 The Grafenberg Spot (G-Spot). To locate the Grafenberg spot, insert two fingers into the vagina and press deeply into its anterior wall. Pubic bone Approximate location of G-spot Emptied bladder Uterus Cervix Urethra Urethral opening (exit point for emission) Anus Anterior vaginal wall or those from cultures who risk a violent reaction from their partners. In spite of its availability, the American College of Obstetricians and Gynecologists has issued strong warnings to women that there is no evidence cosmetic genital surgery is safe or effective (ACOG, 2007). An area inside the body, surrounding the urethra, is what many women report to be an erotically sensitive area, the Grafenberg spot, or G-spot. The name is derived from Ernest Grafenberg, a gynecologist, who first discussed its erotic significance. Located on the front wall of the vagina midway between the pubic bone and the cervix on the vaginal side of the urethra (see Figure 3.4), this area varies in size from a small bean to a half walnut. It can be located by pressing one or two fingers into the front wall of a woman’s vagina. Coital positions such as rear entry, in which the penis makes contact with the spot, may also produce intense erotic pleasure (Ladas, Whipple, & Perry, 1982; Whipple & Komisaruk, 1999). A variety of responses have been reported by women who first locate this spot. Initially, a woman may experience a slight feeling of discomfort or the need to urinate, but shortly thereafter, the tissue may swell and a pleasurable feeling may occur. Women who report orgasms as a result of stimulation of the G-spot describe them as intense and extremely pleasurable (Perry & Whipple, 1981; Whipple, 2002). Though an exact gland or site has not been found in all women, nor do all women experience pleasure when the area is massaged, it has been suggested that the orgasm occurring in the area called the G-spot could be caused by the contact and connection of the richly innervated internal clitoris and the anterior vaginal wall (Foldes & Buisson, 2009). More specifically, by using special instruments and photography that measure changes in the vagina, it was found that the displacement of the anterior vaginal wall that occurs with pressure of the finger on this site, along with movement of the engorged and enlarged clitoris that occurs during sexual arousal, could provide close contact between the internal root of the clitoris and the anterior vaginal wall and thereby lead to what 76 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 77 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles is known as a G-spot orgasm, sometimes with accompanying emission of fluid. This fluid, referred to as the “female ejaculate,” has the appearance of skim milk and is chemically similar to seminal fluid, but different from urine (Komisaruk, Whipple, Nasserzadeh, & Beyer-Flores, 2010). It has been suggested that the emitted fluid comes from the para-urethral glands, which recently have been named the “female prostate gland.” The orgasm and emission that accompanies G-spot stimulation is a healthy part of sexual expression and can be pleasurable. The Uterus and Cervix The uterus (YU-te-rus), or womb, is a hollow, thickwalled, muscular organ held in the pelvic cavity by a number of flexible ligaments and supported by several muscles. It is pear-shaped, with the tapered end, the cervix, extending down and opening into the vagina. If a woman has not given birth, the uterus is about 3 inches long and 3 inches wide at the top; it is somewhat larger in women who have given birth. The uterus expands during pregnancy to the size of a volleyball or larger, to accommodate the developing fetus. The inner lining of the uterine walls, the endometrium (en-doe-MEE-tree-um), is filled with tiny blood vessels. As hormonal changes occur during the monthly menstrual cycle, this tissue is built up and then shed and expelled through the cervical os (opening), unless fertilization has occurred. In the event of pregnancy, the pre-embryo is embedded in the nourishing endometrium. In addition to the more or less monthly menstrual discharge, mucous secretions from the cervix also flow out through the vagina. These secretions tend to be somewhat white, thick, and sticky following menstruation, becoming thinner as ovulation approaches. At ovulation, the mucous flow tends to increase and to be clear, slippery, and stretchy, somewhat like egg white. (Birth control using cervical mucus to determine the time of ovulation is discussed in Chapter 11.) The Ovaries On each side of the uterus, held in place by several ligaments, is one of a pair of ovaries. The ovary is a gonad, an organ that produces gametes (GA-meets), the sex cells containing the genetic material necessary for reproduction. Female gametes are called oocytes (OH-uh-sites), from the Greek words for egg and cell. (Oocytes are commonly referred to as eggs or ova [singular, ovum]. Technically, however, the cell does not become an egg until it completes its final stages of division following fertilization.) The ovaries are the size and shape of large almonds. In addition to producing oocytes, they serve the important function of producing hormones such as estrogen, progesterone, and testosterone. (These hormones are discussed later in this chapter.) At birth, the female’s ovaries contain about half a million oocytes. During childhood, many of these degenerate; then, beginning in puberty and ending after menopause, a total of about 400 oocytes mature and are released during a woman’s reproductive years. The release of an oocyte is called ovulation. The immature oocytes are embedded in saclike structures called ovarian follicles. The fully ripened follicle is called a vesicular or Graffian follicle. At maturation, the follicle ruptures, releasing the oocyte. After the oocyte emerges, the ruptured follicle becomes the corpus luteum (KOR-pus LOO-tee-um) (from the Latin for yellow body), a producer of important hormones; it eventually degenerates. The egg is viable for about 24 hours. Girls got balls. They’re just a little higher “ up, that’s all. —Joan Jett (1960–) The Fallopian Tubes At the top of the uterus are two tubes, one on each side, known as fallopian tubes, uterine tubes, or oviducts. The tubes are about 4 inches long. They extend toward the ovaries but are not attached to them. Female Sex Organs: What Are They For? • 77 yar35317_ch03_068-104.indd Page 78 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Instead, the funnel-shaped end of each tube (the infundibulum) fans out into fingerlike fimbriae (fim-BREE-ah), which drape over the ovary but may not actually touch it. Tiny, hairlike cilia on the fimbriae and ampulla become active during ovulation. Their waving motion, along with contractions of the walls of the tube, transports the oocyte that has been released from the ovary into the fallopian tube. Just within the infundibulum is the ampulla, the widened part of the tube in which fertilization normally occurs if sperm and oocyte are there at the same time. (The process of ovulation and the events leading to fertilization are discussed later in this chapter; fertilization is covered in Chapter 12.) Other Structures There are several other important anatomical structures in the genital areas of both men and women. Although they may not serve reproductive functions, they may be involved in sexual activities. Some of these areas may also be affected by sexually transmitted infections. In women, these structures include the urethra, anus, and perineum. The urethra (yu-REE-thra) is the tube through which urine passes; the urethral opening, or meatus, is located between the clitoris and the vaginal opening. Between the vagina and the anus—the opening of the rectum, through which excrement passes—is a diamond-shaped region called the perineum (per-e-NEE-um). This area of soft tissue covers the muscles and ligaments of the pelvic floor, the underside of the pelvic area extending from the top of the pubic bone (above the clitoris) to the anus. (To learn more about this muscle and Kegel exercises, which can strengthen it, see Chapter 14.) The anus consists of two sphincters, which are circular muscles that open and close like valves. The anus contains a dense supply of nerve endings that, along with the tender rings at the opening, can respond erotically. (For additional discussion about anal eroticism, see Chapter 9.) In sex play or intercourse involving the anus or rectum, care must be taken not to rupture the delicate tissues. This may occur because of the lack of adequate lubrication or very rough anal sex play. Anal sex, which involves insertion of the penis or other object into the rectum, is potentially unsafe, as is vaginal sex, because abrasions of the tissue provide easy passage for pathogens, such as HIV (the virus that causes AIDS), to the bloodstream (see Chapter 16). To practice safer sex, partners who engage in anal intercourse should use a latex condom with a water-based lubricant. Uncorsetted, her friendly bust gives “ promise of pneumatic bliss. —T. S. Eliot (1888–1965) 78 • Chapter 3 The Breasts With the surge of sex hormones that occurs during adolescence, the female breasts begin to develop and enlarge (see Figure 3.5). The reproductive function of the breasts is to nourish offspring through lactation, or milk production. A mature female breast, also known as a mammary gland, is composed of fatty tissue and 15–25 lobes that radiate around a central protruding nipple. Around the nipple is a ring of darkened skin called the areola (a-REE-o-la). Tiny muscles at the base of the nipple cause it to become erect in response to touch, cold, or sexual arousal. When a woman is pregnant, the structures within the breast undergo further development. Directly following childbirth, in response to hormonal signals, small glands within the lobes called alveoli (al-VEE-a-lee) begin producing milk. The milk passes into ducts, each of which has a dilated region for storage; the ducts open to the outside at the nipple. (Breastfeeding is discussed in Chapter 12.) During lactation, a woman’s breasts increase in size from enlarged glandular tissues and stored milk. Because there is little variation in the amount Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 79 6/25/12 7:25 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles • FIGURE 3.5 Suspensory ligaments Fat Ribs The Female Breast. Front and cross-section views. Chest wall Areola Nipple Mammary glands Milk ducts Alveoli of glandular tissue among women, the amount of milk produced does not vary with breast size. In women who are not lactating, breast size depends mainly on fat content, which is determined by hereditary factors. In the Western culture, women’s breasts capture a significant amount of attention and serve an erotic function. Many, but not all, women find breast stimulation intensely pleasurable, whether it occurs during breastfeeding or sexual contact. Partners tend to be aroused by both the sight and the touch of women’s breasts. Although there is no basis in reality, some believe that large breasts denote greater sexual responsiveness than small breasts. (See Chapter 13 for a discussion of breast enhancement.) (Table 3.1 provides a summary of female sexual anatomy.) Western culture tends to be ambivalent about breasts and nudity. Many people are comfortable with artistic portrayals of the nude female body. Female Sex Organs: What Are They For? • 79 yar35317_ch03_068-104.indd Page 80 6/25/12 7:26 PM user-f502 TABLE 3.1 • /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Summary Table of Female Sexual Anatomy External Structures (Vulva) Mons pubis (mons veneris) Fatty tissue that covers the area of the pubic bone Clitoris Center of sexual arousal Clitoral hood Covers the glans clitoris when the clitoris is not engorged Crura (singular, crus) Tips of erectile tissue that attach to the pelvic bones Corpora cavernosa Hollow chambers that fill with blood and swell during sexual arousal Labia majora (major lips) Two folds of spongy flesh that extend from the mons pubis and run downward along the sides of the vulva Labia minora (minor lips) Smaller, hairless folds within the labia majora that meet above the clitoris to form the clitoral hood Vestibule (vaginal opening) Area enclosed by the labia minora Bartholin’s glands Glands that secrete a small amount of moisture during sexual arousal Internal Structures Vagina (birth canal) Flexible, muscular structure in which menstrual flow and babies pass Introitus The lower part of the vagina Hymen Thin membrane that partially covers the introitus and contains a relatively large number of blood vessels Grafenberg spot (G-spot) Located on the front wall of the vagina, an erotically sensitive area that may produce intense erotic pleasure and a fluid emission in some women Uterus (womb) Hollow, thick-walled muscular organ in which a fertilized ovum implants and develops until birth Cervix Lower end of the uterus that extends down and opens to the vagina Endometrium Inner lining of the uterine wall to which the fertilized egg attaches; partly discharged (if pregnancy does not occur) with the menstrual flow Os Opening to the cervix Ovary (gonad) Organ that produces gametes (see below) Gametes Sex cells containing the genetic material necessary for reproduction; also referred to as oocytes, eggs, ova (singular, ovum) Ovarian follicles Saclike structures that contain the immature oocytes Corpus luteum Tissue formed from a ruptured ovarian follicle that produces important hormones after the oocyte emerges Fallopian tubes (oviducts) Uterine tubes that transport the oocyte from the ovary to the uterus Infundibulum Funnel-shaped end of each fallopian tube Fimbriae Fingerlike projections that drape over the ovary and help transport the occyte from the ovary into the fallopian tube Cilia Tiny, hairlike structures that provide waving motion to help transport the oocyte within the fallopian tube to the ovary Ampulla Widened part of the fallopian tube in which fertilization normally occurs Other Structures Urethra 80 Tube through which urine passes Urethral opening (meatus) Opening in the urethra, through which urine is expelled Anus Opening in the rectum, through which excrement passes Perineum Area that lies between the vaginal opening and the anus Pelvic floor Underside of the pelvic area, extending from the top of the pubic bone (above the clitoris) to the anus • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 81 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles During ovulation, the ovarian follicle swells and ruptures, releasing the mature oocyte to begin its journey through the fallopian tube. • Female Sexual Physiology Just how do the various structures of the female anatomy function to produce the menstrual cycle? The female reproductive cycle can be viewed as having two components (although, of course, multiple biological processes are involved): (1) the ovarian cycle, in which eggs develop, and (2) the menstrual, or uterine, cycle, in which the womb is prepared for pregnancy. These cycles repeat approximately every month for about 35 or 40 years. The task of directing these processes belongs to a class of chemicals called hormones. Reproductive Hormones Hormones are chemical substances that serve as messengers, traveling within the body through the bloodstream. Most hormones are composed of either amino acids (building blocks of proteins) or steroids (derived from cholesterol). They are produced by the ovaries and the endocrine glands—the adrenals, pituitary, and hypothalamus. Hormones assist in a variety of tasks, including development of the reproductive organs and secondary sex characteristics during puberty, regulation of the menstrual cycle, maintenance of pregnancy, initiation and regulation of childbirth, initiation of lactation, and, to some degree, the regulation of libido (li-BEE-doh; sex drive or interest). Hormones that act directly on the gonads are known as gonadotropins (go-nad-a-TRO-pins). Among the most important of the female hormones are the estrogens, which affect the maturation of the reproductive organs, menstruation, and pregnancy, and progesterone, which helps to maintain the uterine lining until menstruation occurs. (The principal hormones involved in a woman’s reproductive and sexual life and their functions are described in Table 3.2.) (Testosterone is discussed later in this chapter.) The Ovarian Cycle The development of female gametes is a complex process that begins even before a woman is born. In infancy and childhood, the cells develop into ova (eggs). During puberty, hormones trigger the completion of the process of oogenesis Female Sexual Physiology • 81 yar35317_ch03_068-104.indd Page 82 6/25/12 7:26 PM user-f502 TABLE 3.2 • /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Female Sex Hormones Hormone Where Produced Functions Estrogen (including estradiol, estrone, estriol) Ovaries, adrenal glands, placenta (during pregnancy) Promotes maturation of reproductive organs, development of secondary sex characteristics, and growth spurt at puberty; regulates menstrual cycle; sustains pregnancy; maintains libido Progesterone Ovaries, adrenal glands, placenta Promotes breast development, maintains uterine lining, regulates menstrual cycle, sustains pregnancy Gonadotropin-releasing hormone (GnRH) Hypothalamus Promotes maturation of gonads, regulates menstrual cycle Follicle-stimulating hormone (FSH) Pituitary Regulates ovarian function and maturation of ovarian follicles Luteinizing hormone (LH) Pituitary Assists in production of estrogen and progesterone, regulates maturation of ovarian follicles, triggers ovulation Human chorionic gonadotropin (HCG) Embryo and placenta Helps sustain pregnancy Testosterone Adrenal glands and ovaries Helps stimulate sexual desire Oxytocin Hypothalamus Stimulates uterine contractions during childbirth and possibly during orgasm, promotes milk let-down Prolactin Pituitary Stimulates milk production Prostaglandins All body cells Mediates hormone response, stimulates muscle contractions (oh-uh-JEN-uh-sis), literally, “egg beginning” (see Figure 3.6). The oocyte, otherwise referred to as germ cell or immature ovum, marks the start of mitosis, the process by which a cell duplicates the chromosome in its cell nucleus. Oogenesis results in the formation of both primary oocytes, before birth, and as secondary oocytes after it and as part of ovulation. This process, called the ovarian cycle (or menstrual cycle), continues until a woman reaches menopause. The ovarian cycle averages 28 days in length, although there is considerable variation among women, ranging from 21 to 40 days. In their own particular cycle length after puberty, however, most women experience little variation. Generally, ovulation occurs in only one ovary each month, alternating between the right and left sides with each successive cycle. If a single ovary is removed, the remaining one begins to ovulate every month. The ovarian cycle has three phases: follicular (fo-LIK-u-lar), ovulatory (ov-UL-a-tor-ee), and luteal (LOOtee-ul) (see Figure 3.7). As an ovary undergoes its changes, corresponding changes occur in the uterus. Menstruation marks the end of this sequence of hormonal and physical changes in the ovaries and uterus. The Follicular Phase On the first day of the cycle, gonadotropin-releasing hormone (GnRH) is released from the hypothalamus. GnRH begins to stimulate the pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), initiating the follicular phase. During the first 10 days, 10–20 ovarian follicles begin to grow, stimulated by FSH and LH. In 98–99% of cases, only one of the follicles will mature completely during this period. 82 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 83 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles • FIGURE 3.6 Oogonium (46 chromosomes) Oogenesis. This diagram charts the development of an ovum, beginning with embryonic development of the oogonium and ending with fertilization of the secondary oocyte, which then becomes the diploid zygote. Primary oocytes are present in a female at birth; at puberty, hormones stimulate the oocyte to undergo meiosis. mitosis Mitosis Many oogonia growth and differentiation Primary oocyte (46 chromosomes) before birth after birth Meiosis I sexual maturity meiosis ovulation First polar body Secondary oocyte (23 chromosomes) Fertilization Sperm (23 chromosomes) Meiosis II meiosis meiosis Second polar body Diploid zygote Polar bodies degenerating (The maturation of more than one oocyte is one factor in multiple births.) All the developing follicles begin secreting estrogen. Under the influence of FSH and estrogen, the oocyte matures, bulging from the surface of the ovary. This may also be referred to as the proliferative phase. The ovulatory phase begins at about day 11 of the cycle and culminates with ovulation at about day 14. Stimulated by an increase of LH from the pituitary, the primary oocyte undergoes cell division and becomes ready for ovulation. The ballooning follicle wall thins and ruptures, and the oocyte enters the abdominal cavity near the beckoning fimbriae. Ovulation is now complete. Some women experience a sharp twinge, called Mittelschmerz, on one side of the lower abdomen during ovulation. A very slight bloody discharge from the vagina may also occur. Occasionally, more than one ovum is released. If two ova are fertilized, nonidentical twins will result. If one egg is fertilized and divides into two separate zygotes, identical twins will develop. Ovulatory Phase The Luteal Phase Following ovulation, estrogen levels drop rapidly, and the ruptured follicle, still under the influence of increased LH, becomes a corpus luteum, which secretes progesterone and small amounts of estrogen. Increasing levels of these hormones serve to inhibit pituitary release of FSH and LH. Unless fertilization has occurred, the corpus luteum deteriorates. In the event of pregnancy, the corpus luteum maintains its hormonal output, helping to Female Sexual Physiology • 83 yar35317_ch03_068-104.indd Page 84 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Menstrual Phase Follicular Phase (also called the Proliferative Phase) (Menstruation) (Follicle development) Fallopian tube Oocyte disintegrates Uterine lining Uterine lining renews Ovary Fimbriae Uterus Uterine lining sloughs off and passes out of the body through the cervix and vagina Maturing oocyte in follicle Immature oocytes Cervix Vagina Ovulatory Phase Luteal Phase Uterine lining thickens Oocyte travels through tube Remaining cells of follicle develop into corpus luteum Oocyte is released Lining continues to thicken • FIGURE 3.7 Ovarian and Menstrual Cycles. The ovarian cycle consists of the activities within the ovaries and the development of oocytes; it includes the follicular, ovulatory, and luteal phases. The menstrual cycle consists of processes occurring in the uterus. Hormones regulate these cycles. sustain the pregnancy. The hormone human chorionic gonadotropin (HCG)— similar to LH—is secreted by the embryo and signals the corpus luteum to continue until the placenta has developed sufficiently to take over hormone production. The luteal phase typically lasts from day 14 (immediately after ovulation) through day 28 of the ovarian cycle. Even when cycles are more or less than 28 days, the duration of the luteal phase remains the same; the time between ovulation and the end of the cycle is always 14 days. At this point, the ovarian hormone levels are at their lowest, GnRH is released, and FSH and LH levels begin to rise. The Menstrual Cycle As hormone levels decrease following the degeneration of the corpus luteum, the uterine lining (endometrium) is shed because it will not be needed to help sustain the fertilized ovum. The shedding of endometrial tissue and the bleeding 84 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 85 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles that accompanies it are, collectively, a monthly event in the lives of women from puberty through menopause. Cultural and religious attitudes, as well as personal experience, influence our feelings about this phenomenon. (The physical and emotional effects of menstruation are discussed later in this section. The onset of menstruation and its effect on a woman’s psychosexual development are discussed in Chapter 6. Menopause is discussed in Chapter 7.) Most American women who menstruate use sanitary pads, panty liners, or tampons to help absorb the flow of menstrual blood. While pads and panty liners are used outside the body, tampons are placed inside the vagina. For a wide variety of reasons, including environmental concerns, comfort, chemical residues, and toxic shock syndrome (a bacterial infection that can occur in menstruating women and cause a person to go into shock; discussed in Chapter 13), women are turning to alternative means for catching menstrual flow. While some Americans may question the use of alternative products, across time and culture a wide variety of methods have been used to absorb the flow of blood. Cloth menstrual pads are reusable, washable, and quite comfortable. For those desiring to wear something internally, other products, called The Keeper, DivaCuptm, or Instead, consist of a menstrual cup that is held in place by suction in the lower vagina and acts to collect menstrual fluid. Some women have used the diaphragm or cervical cap in a similar manner. Reusable sea sponges can work like tampons in absorbing blood. Boiling the sponge before use and between uses can help to rid it of possible ocean pollutants and help to keep it sanitary. Sewing or tying a piece of cotton string on the sponge for easy retrieval is suggested. Most likely, the majority of American women will continue to rely on more widely available and advertised commercial tampons or sanitary pads; however, alternatives provide women with an opportunity to take charge of how they respond to their menstrual flow and the environmental impacts of that decision. The menstrual cycle (or uterine cycle), is divided into three phases: menstrual, proliferative, and secretory. What occurs within the uterus is inextricably related to what is happening in the ovaries, but only in their final phases do the two cycles actually coincide (see Figure 3.8). An array of choices that collect and absorb menstrual flow are now available to women. The Menstrual Phase With hormone levels low because of the degeneration of the corpus luteum, the outer layer of the endometrium becomes detached from the uterine wall. The shedding of the endometrium marks the beginning of the menstrual phase. This endometrial tissue, along with mucus, other cervical and vaginal secretions, and a small amount of blood (2–5 ounces per cycle), Female Sexual Physiology • 85 yar35317_ch03_068-104.indd Page 86 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles • FIGURE 3.8 The Menstrual Cycle, Ovarian Cycle, and Hormone Levels. This chart compares the activities of the ovaries and uterus and shows the relationship of blood hormone levels to these activities. Highest intimacy and sex drive Pituitary hormone levels in bloodstream LH FSH Ovarian hormone levels in bloodstream Estrogen Progesterone Testosterone/Androgen Ovarian cycle Follicle Ovum Corpus luteum degenerates Menstrual cycle Menstrual flow Menses Endometrium Menstrual flow Estrogenic phase Day 1 Ovulation Day 14 Progestational phase Menses Day 28 is expelled through the vagina. The menstrual flow, or menses (MEN-seez), generally occurs over a period of 3–5 days. FSH and LH begin increasing around day 5, marking the end of this phase. A girl’s first menstruation is known as menarche (MEH-nar-kee). The Proliferative Phase The proliferative phase lasts about 9 days. During this time, the endometrium thickens in response to increased estrogen. The mucous membranes of the cervix secrete a clear, thin mucus with a crystalline structure that facilitates the passage of sperm. The proliferative phase ends with ovulation. The Secretory Phase During the first part of the secretory phase, with the help of progesterone, the endometrium begins to prepare for the arrival of a fertilized ovum. Glands within the uterus enlarge and begin secreting glycogen, a cell nutrient. The cervical mucus thickens and starts forming a plug to seal off the uterus in the event of pregnancy. If fertilization does not occur, the corpus luteum begins to degenerate, as LH levels decline. Progesterone levels then fall, and the endometrial cells begin to die. The secretory phase lasts 14 days, corresponding with the luteal phase of the ovarian cycle. It ends with the shedding of the endometrium. 86 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 87 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Menstrual Synchrony Women who live or work together often report developing similarly timed menstrual cycles (Cutler, 1999). Termed menstrual synchrony, this phenomenon appears to be related to the sense of smell—more specifically, a response to pheromones, chemical substances secreted into the air. Though there is considerable controversy among researchers as to whether the phenomenon actually exists, if it does, there could be implications for birth control, sexual attraction, and other aspects of women’s lives. (Pheromones are discussed later in the chapter.) Menstrual Effects American women have divergent attitudes toward menstrua- tion. For some women, menstruation is a problem; for others, it is simply a fact of life that creates little disruption. For individual women, the problems associated with their menstrual period may be physiological, emotional, or practical. The vast majority of menstruating women notice at least one emotional, physical, or behavioral change in the week or so prior to menstruation. Most women describe the changes negatively: breast tenderness and swelling, abdominal bloating, irritability, cramping, depression, or fatigue. Some women also report positive changes such as increased energy, heightened sexual arousal, or a general feeling of well-being. For most women, changes during the menstrual cycle are usually mild to moderate; they appear to have little impact on their lives. The most common problems associated with menstruation are discussed below. Menstrual Period Slang “ that time of the month monthlies the curse female troubles a visit from my friend a visit from Aunt Flo a visit from George on the rag on a losing streak falling off the roof Premenstrual Syndrome A collection of physical, emotional, and psychological changes that may occur 7–14 days before a woman’s menstrual period is known as premenstrual syndrome (PMS). These symptoms disappear soon after the start of menstrual bleeding. Though no one knows for sure what causes PMS, it seems to be linked to alterations in the levels of sex hormones and brain chemicals, or neutrotransmitters. Controversy exists over the difference between premenstrual discomfort and true PMS. Premenstrual discomfort is a common occurrence, affecting about 75% of all menstruating women (InteliHealth, 2005). Only about 3–8% of women, however, have symptoms that are severe enough to be labeled PMS. While some doctors equate premenstrual dysphoric disorder to PMS, others use a less stringent definition for PMS, which includes mild to moderate symptoms. Symptoms of PMS fall into two categories: physical symptoms, which may include bloating, breast tenderness, swelling and weight gain, headaches, cramping, migraine headaches, and food cravings; and psychological and emotional symptoms, which include fatigue, depression, irritability, crying, and changes in libido. For many, symptoms may be worse some months and better other ones. It may also be comforting to know that in most women, PMS symptoms begin to subside after the age of 35 and at menopause. Menorrhagia At some point in her menstrual life, nearly every woman experiences heavy or prolonged bleeding during her menstrual cycle, also known as menorrhagia. Although heavy menstrual bleeding is common among most women, only a few experience blood loss severe enough for it to be defined as menorrhagia. Signs and symptoms may include a menstrual flow that soaks through one or more sanitary pads or tampons every hour for several consecutive hours, the need to use double sanitary protection throughout the menstrual flow, menstrual flow that includes large blood clots, and/or heavy menstrual flow that interferes with the regular lifestyle. Though the cause of heavy menstrual bleeding is unknown, a number of conditions may cause menorrhagia, including hormonal Female Sexual Physiology • 87 yar35317_ch03_068-104.indd Page 88 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles imbalances, uterine fibroids, having an IUD, cancer, or certain medications. The combined effect of hormonal imbalances and uterine fibroids accounts for 80% of all cases of menorrhagia. Excessive or prolonged menstrual bleeding can lead to iron deficiency anemia and other medical conditions; thus, it is advisable for women with this problem to seek medical care and treatment. Dysmenorrhea While menstrual cramps are experienced by some women before or during their periods, a more persistent, aching, and serious pain sufficient to limit a woman’s activities is called dysmenorrhea. There are two types of dysmenorrhea. Primary dysmenorrhea is not associated with any diagnosable pelvic condition. It is characterized by pain that begins with (or just before) uterine bleeding when there is an absence of pain at other times in the cycle. It can be very severe and may be accompanied by nausea, weakness, or other physical symptoms. In secondary dysmenorrhea, the symptoms may be the same, but there is an underlying condition or disease causing them; pain may not be limited to the menstrual phase alone. Secondary dysmenorrhea may be caused by pelvic inflammatory disease (PID), endometriosis, endometrial cancer, or other conditions that should be treated. (See Chapters 13 and 15.) The effects of dysmenorrhea can totally incapacitate a woman for several hours or even days. Once believed to be a psychological condition, primary dysmenorrhea is now known to be caused by high levels of prostaglandins (pros-ta-GLANdins), a type of hormone with a fatty-acid base that is found throughout the body. Drugs like ibuprofen (Motrin and Advil) relieve symptoms by inhibiting the production of prostaglandins. Some doctors may prescribe birth control pills. Amenorrhea When women do not menstruate for reasons other than aging, the condition is called amenorrhea (ay-meh-neh-REE-a). Principal causes of amenorrhea are pregnancy and breastfeeding. Lack of menstruation, if not a result of pregnancy or nursing, is categorized as either primary or secondary amenorrhea. Women who have passed the age of 16 and never menstruated are diagnosed as having primary amenorrhea. It may be that they have not yet reached their critical weight (when an increased ratio of body fat triggers menstrual cycle–inducing hormones) or that they are hereditarily late maturers. But it can also signal hormonal deficiencies, abnormal body structure, or an intersex condition or other genital anomaly that makes menstruation impossible. Most primary amenorrhea can be treated with hormone therapy. Secondary amenorrhea exists when a previously menstruating woman stops menstruating for several months. If it is not due to pregnancy, breastfeeding, or the use of hormonal contraceptives, the source of secondary amenorrhea may be found in stress, lowered body fat, heavy physical training, cysts or tumors, disease, or hormonal irregularities. Anorexia (discussed in Chapter 13) is a frequent cause of amenorrhea. If a woman is not pregnant, is not breastfeeding, and can rule out hormonal contraceptives as a cause, she should see her health-care practitioner if she has gone 3 months without menstruating. Lifestyle changes or treatment of the underlying condition can almost always correct amenorrhea, unless it is caused by a congenital anomaly. Because there is no known harm associated with amenorrhea, the condition is corrected when an underlying problem presents itself or it causes a woman psychological distress. Sexuality and the Menstrual Cycle Although studies have tried to determine whether there is a biologically based cycle of sexual interest and activity 88 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 89 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles practically speaking Many factors can influence the way we experience the changes that occur over the course of the menstrual cycle. While the vast majority of women feel few and minor changes, others experience changes that are uncomfortable and debilitating. The variations can be significant in any one woman and from month to month. For women, recognizing their menstrual patterns, learning about their bodies, and recognizing and dealing with existing difficulties can be useful in heading off or easing potential problems. Different remedies work for different women. We suggest that you try varying combinations of them and keep a record of your response to each. Following are some common changes that occur during the menstrual cycle and self-help means to address them. For Vaginal Changes The mucous membranes lining the walls of the vagina normally produce clear, white, or pale yellow secretions. These secretions pass from the cervix through the vagina and vary in color, consistency, odor, and quantity, depending on the phase of the menstrual cycle, the woman’s health, and her unique physical characteristics. It is important for you to observe your secretions periodically and note any changes, especially if symptoms accompany them. Because self-diagnosis of unusual discharges is inaccurate over half the time, it is wise to go ahead with selftreatment only after a diagnosis is made by a health-care practitioner. Call a health professional if you feel uncertain or suspicious and/or think you may have been exposed to a sexually transmitted infection. Here are some simple guidelines that may help a woman avoid getting vaginitis: 4. Wear cotton underpants with a cotton crotch. Nylon does not “breathe,” and it allows heat and moisture to build up, creating an ideal environment for infectious organisms to reproduce. 5. If you use a vaginal lubricant, be sure it is water-soluble. Oil-based lubricants such as Vaseline encourage bacterial growth. 6. Socialize with others or go to a support group to help reduce the stress that may cause or exacerbate the infection. For Premenstrual Changes 1. Consume a well-balanced diet, with plenty of whole-grain cereals, fruits, and vegetables. 2. Moderate your intake of alcohol, avoid tobacco, and get sufficient sleep. 3. Exercise at least 30–45 minutes a day. Aerobic exercise brings oxygen to body tissues and stimulates the production of endorphins, chemical substances that help promote feelings of well-being. For Cramps 1. Relax and apply heat by using a heating pad or hot-water bottle (or, in a pinch, a cat) applied to the abdominal area may help relieve cramps; a warm bath may also help. 2. Get a lower-back or other form of massage, such as acupressure, or Shiatsu. 1. Avoid douching and vaginal deodorants, especially deodorant suppositories or tampons. They upset the natural chemical balance of the vagina. 3. Take prostaglandin inhibitors, such as aspirin and ibuprofen, to reduce cramping of the uterine and abdominal muscles. Aspirin increases menstrual flow slightly, whereas ibuprofen reduces it. Stronger antiprostaglandins may be prescribed by your health-care practitioner. 2. Maintain good genital hygiene by washing the labia and clitoris regularly (about once a day) with mild soap. 4. Having an orgasm (with or without a partner) is reported by some women to relieve menstrual congestion and cramping. 3. After a bowel movement, wipe the anus from front to back, away from the vagina, to prevent contamination with fecal bacteria. When symptoms are severe, further medical evaluation is needed. in women that correlates with the menstrual cycle (such as higher interest around ovulation), the results have been varied. There is also variation in how people feel about sexual activity during different phases of the menstrual cycle. There has been a general taboo in our culture, as in many others, against sexual intercourse during menstruation. This taboo may be based on religious or cultural beliefs. Among Orthodox Jews, for example, women are required to refrain from intercourse for 7 days following the end of menstruation. They may then resume sexual activity after a ritual bath, the mikvah. Contact with Female Sexual Physiology • 89 yar35317_ch03_068-104.indd Page 90 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles blood may make some people squeamish. Some women, especially at the beginning of their period, feel bloated or uncomfortable; they may experience breast tenderness or a general feeling of not wanting to be touched. Others may find that sexual activity helps relieve menstrual discomfort. For some couples, merely having to deal with the logistics of bloodstains, bathing, and laundry may be enough to discourage them from intercourse at this time. For many people, however, menstrual blood holds no special connotation. In a study of 108 women aged 18–23, females described their experiences with sexuality during menstruation. Nearly one half, most of whom were in committed relationships, stated they had sexual activity during their menstrual cycle (Allen & Goldberg, 2009). Young adults who were comfortable with menstrual sex saw it as just another part of a committed intimate relationship. It is important to note that although it is unusual, conception can occur during menstruation. Some women find that a diaphragm or menstrual cup can collect the menstrual flow. Menstrual cups, however, are not a contraceptive. It is not recommended that women engage in intercourse while a tampon is inserted because of possible injury to the cervix. And inventive lovers can, of course, find many ways to give each other pleasure that do not require putting the penis into the vagina. • Female Sexual Response The ways in which individuals respond to sexual arousal are highly varied. Women’s sexuality, though typically thought of as personal and individual, is significantly influenced by the social groups to which women belong. Sociocultural variables include gender, religious preference, class, educational attainment, age, marital status, race, and ethnicity. For many women, gender—the social and cultural characteristics associated with being male or female—is probably the most influential variable in shaping their sexual desires, behaviors, and partnerships. Because gender is largely defined by cultural expectations, women’s sexual experiences must be understood in terms of cultural, political, and relational forces. New research into the anatomy and physiology of sexuality has helped us to increase our understanding of orgasm. By looking beyond the genitals to the central nervous system, where electrical impulses travel from the brain to the spinal cord, researchers are examining nerves and pathways to better understand the biology of the orgasm. What is probably most critical to all of these functions are the ways we interpret sexual cues. Though scientific research has contributed much to our understanding of sexual arousal and response, there is still much to be learned. One way in which researchers investigate and describe phenomena is through the creation of models, hypothetical descriptions used to study or explain something. Although models are useful for promoting general understanding or for assisting in the treatment of specific clinical problems, we should remember that they are only models. It may be helpful to think of sexual functioning as interconnected, linking desire, arousal, orgasm, and satisfaction. Turbulence or distraction at any one point affects the functioning of the others. Passion, though a bad regulator, is a “ powerful spring. —Ralph Waldo Emerson (1803–1882) 90 • Chapter 3 Sexual Response Models A number of sexologists have attempted to outline the various physiological changes that both men and women undergo when they are sexually stimulated. Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 91 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles think about it Sexual Fluidity: Women’s Variable Sexual Attractions When the media report stories about same-sex lovers, such as actress Anne Heche leaving Ellen DeGeneres for a man, Cynthia Nixon (from Sex and the City) leaving her male partner of 15 years for a woman, and Julie Cypher leaving a heterosexual marriage for Melissa Etheridge then later leaving her for a man, what are your responses? Are these incidents simply flukes? Are the women confused? Bisexual? None of these, according to Lisa Diamond, professor of psychology and gender studies at the University of Utah. Rather, she has coined the term “sexual fluidity” to describe sexual desires and attractions as situation-dependent in sexual responsiveness (Diamond, 2008). Based on her own research and analysis of animal mating and women’s sexuality, Diamond suggests that female desire may be dictated by both intimacy and emotional connection. She came to this conclusion after 10 years following the erotic attractions of nearly 100 young women who, at the start of her work, identified themselves as lesbian, bisexual, or refused a label. From her analysis of their shifts between sexual identities and descriptions of their erotic lives, Diamond suggests that for her participants and possibly for women on the whole, desire is malleable, embedded in the nature of female desire, and cannot be captured by asking women to categorize their attractions. Among the women in her study who called themselves lesbian, one third reported attraction solely to women while the other two thirds revealed periodic and genuine desire and attraction to men. When discussing sexual orientation, Diamond sees significance in the fact that many of her subjects agreed with the statement “I am the kind of person who becomes physically attracted to the person rather than their gender.” Thus it is, in the cases of Diamond’s subjects, that emotional closeness overrode innate orientation, resulting in attraction and desire. This concept seems to violate the core underlying assumption of our model of sexuality: that sexual orientation is defined by sexual behavior. Not long ago, the sexualities—heterosexuality, homosexuality, and even bisexuality—were categorical. Sexual attraction and desire, sexual behavior, and sexual identity were assumed to be congruent; same-gender sexual attraction/ behavior assumed a gay, lesbian, or bisexual identity; and other sexual attraction/behavior assumed a heterosexual identity (Schecter, 2009). Now, Diamond’s work along with others’, reveals this may be true for some women, but not true for all. In fact, desire/behavior and orientation/identity do not always match up. The more scholars learn about sexual desire, the more it becomes apparent that it involves a complex interplay among biological, environmental, psychological, cultural, and interpersonal factors. Evidence points to three characteristics about desire: (1) It is both hormonally and situationally driven, (2) individuals are often unaware of the full range of their desires, and (3) women’s sexual desires show more variability than do men’s. Probably the largest review of all the published data on the subject around the variability of women’s sexual desires was published by Roy Baumeister (2000), professor of psychology at Florida State University. The study found that women show greater variability than men in a wide range of sexual behaviors, including desired frequency of sex, preferred contexts for sexual behavior, types and frequency of fantasy, and desirable partner characteristics. Nevertheless, sex researchers still do not understand the mechanisms that underlie sexual fluidity. While tremendous strides have been made to foster greater acceptance of a diversity of sexual expression, sexual minorities as a whole still remain isolated and unsupported. Textbooks, media, and culture continue to assume that there is a fixed model of same-sex sexuality, in spite of the fact that many individuals know differently. Although the notion of sexual fluidity may be confusing, frightening, or threatening to some, it does offer one more variable to the broad spectrum of sexual expression of which humans are capable and can celebrate. Think Critically 1. Is sexual orientation innate and/or fixed? If so, at what age? How do you know this? 2. Have you experienced sexual fluidity? If so, what were your reactions? 3. What would you do if your same-sex or other-sex best friend told you that he or she was romantically interested in you? Three important models are described here. The sequence of changes and patterns that take place in the body during sexual arousal is referred to as the sexual response cycle. Masters and Johnson’s four-phase model of sexual response identifies the significant stages of response as excitement, plateau, orgasm, and resolution (see Figure 3.9). Helen Singer Kaplan (1979) collapses the excitement and plateau phases into one, eliminates the resolution phase, and adds a phase Female Sexual Response • 91 yar35317_ch03_068-104.indd Page 92 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Pubic bone Uterus elevates Bladder Clitoral hood Clitoris Urethra Labia minora Vaginal lubrication appears Labia majora Clitoris engorges with blood Labia minora swell Anus Labia majora swell Unaroused Excitement Clitoral shaft and glans swell; glans retracts beneath hood Uterus elevates further Labia minora deepen in color and enlarge Upper part of vagina expands Labia majora separate from the vaginal opening Vaginal wall forms orgasmic platform Color of labia deepens Late Excitement or Plateau Clitoris withdraws under clitoral hood Bartholin’s glands may secrete a small amount of fluid Excitement Contractions in uterus Clitoris remains retracted under hood Rhythmic contractions in vagina Orgasmic platform contracts Rectal sphincter contracts Anal sphincter contracts Orgasm Orgasm Uterus lowers Seminal pool Orgasmic platform disappears Resolution 92 • Chapter 3 Vagina returns to normal • FIGURE 3.9 Clitoris returns to unaroused position Masters and Johnson Stages of Female Sexual Response (internal, left; and external, right) Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 93 6/25/12 7:26 PM user-f502 TABLE 3.3 • /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Models of the Sexual Response Cycle Psychological/Physiological Process Name of Phase People make a conscious decision to have sex even if there might not be emotional or physical desire. Willingness (Loulan) Some form of thought, fantasy, or erotic feeling causes individuals to seek sexual gratification. (An inability to become sexually aroused may be due to a lack of desire, although some people have reported that they acquire sexual desire after being sexually aroused.) Desire (Kaplan, Loulan) Physical and/or psychological stimulation produces characteristic physical changes. In men, increased amounts of blood flow to the genitals produce erection of the penis; the scrotal skin begins to smooth out, and the testicles draw up toward the body. Later in this phase, the testes increase slightly in size. In women, vaginal lubrication begins, the upper vagina expands, the uterus is pulled upward, and the clitoris becomes engorged. In both women and men, the breasts enlarge slightly, and the nipples may become erect. Both men and women experience increasing muscular contractions. Excitement (Masters/Johnson, Loulan) Excitement (Kaplan) Sexual tension levels off. In men, the testes swell and continue to elevate. The head of the penis swells slightly and may deepen in color. In women, the outer third of the vagina swells, lubrication may slow down, and the clitoris pulls back. Coloring and swelling of the labia increase. In both men and women, muscular tension, breathing, and heart rate increase. Plateau (Masters/Johnson) Increased tension peaks and discharges, affecting the whole body. Rhythmic muscular contractions affect the uterus and outer vagina in women. In men, there are contractions of the tubes that produce and carry semen, the prostate gland, and the urethral bulb, resulting in the expulsion of semen (ejaculation). Orgasm (Masters/Johnson, Kaplan, and Loulan) The body returns to its unaroused state. In some women, this does not occur until after repeated orgasms. Resolution (Masters/Johnson) Pleasure is one purpose of sexuality and can be defined only by the individual. One can experience pleasure during all or only some of the above stages, or one can leave out any of the stages and still have pleasure. Engorgement (Loulan) Pleasure (Loulan) to the beginning of the process. Kaplan’s tri-phasic model of sexual response includes the desire, excitement, and orgasm phases. Though Masters and Johnson’s and Kaplan’s are the most widely cited models used to describe the phases of the sexual response cycle, they do little to acknowledge the affective parts of human response. A third but much less known pattern is Loulan’s sexual response model, which incorporates both the biological and affective components into a six-stage cycle. Beyond any questions of similarities and differences in the female and male sexual response cycle is the more significant issue of variation in how individuals experience each phase. The diversity of experiences can be described only by the individual. (These models are described and compared in Table 3.3.) Female Sexual Response • 93 yar35317_ch03_068-104.indd Page 94 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles To help organize our thinking about the complexities of human behavior, the dual control model provides a theoretical perspective of sexual response that is based on brain function and the interaction between sexual excitation (responding with arousal to sexual stimuli) and sexual inhibition (inhibiting sexual arousal) (Bancroft, Graham, Janssen, & Sanders, 2009). The authors of this model argue that, though much research has been dedicated to understanding sexual excitation, little research has been conducted on the inhibitory brain mechanisms which provide an equally significant role in sexual arousal and response. They purport that the adaptive role the inhibitory mechanism produces is relevant to our understanding of “normal” sexuality, individual variability, and problematic sexuality. The functions of the inhibitory response can be found in the following circumstances: (1) When sexual activity in a specific situation is potentially risky (as when you or your partner suspects an unintended pregnancy could result); (2) when a nonsexual challenge occurs and sex needs to be suppressed (as when a child calls out for help); (3) when excessive involvement in the pursuit of sexual pleasure distracts from other important functions (as when someone is late for work because he or she is distracted by viewing sexually explicit materials); (4) when social or environmental pressure results in suppression of reproductive behavior (as when someone is so stressed during finals week, he or she doesn’t feel like having sex); and (5) when the consequences of continued excessive sexual behavior potentially reduces possible conception (as when repeated ejaculations can result in lower sperm count). A major finding of the dual control model is that it views excitation and sexual inhibition as separate systems, as opposed to other models that view these as two ends of a single dimension. Additional findings from this model include the following: ■ Though most people fall in the moderate range on propensities toward ■ ■ ■ ■ ■ sexual excitation and sexual inhibition, there is great variability from one person to the next. Men, on average, score higher on excitation and lower on inhibition than women. Gay men, on average, score higher on excitation and lower on inhibition than straight men. Bisexual women, on average, score higher on excitation than lesbian and straight women. Excitation lessens with age for men and women; however, inhibition is not age-related in women but is somewhat age-related in men. The relation between negative mood and sexuality is best predicted by inhibition scores in men, but by excitation scores in women. The dual control model postulates that individuals who have a low propensity for sexual excitation or a high propensity for sexual inhibition are more likely to experience difficulties related to sexual response or sexual interest. Furthermore, those who have a high propensity for sexual excitation or low propensity for sexual inhibition are more likely to engage in problematic sexuality such as high-risk sexual behaviors, for example, not using a condom. Because the focus is on sexual arousal, there remain questions about if and how this model might apply to orgasm. As long as researchers see it as a model rather than as a description of reality, then the model and questionnaire used for investigating it can be improved. 94 • Chapter 3 Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 95 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles Desire: Mind or Matter? Desire is the psychological component of sexual arousal. Although we can experience desire without becoming aroused, and in some cases become aroused without feeling desire, some form of erotic thought or feeling is usually involved in our sexual behavior. The physical manifestations of sexual arousal involve a complex interaction of thoughts and feelings, sensory organs, neural responses, and hormonal reactions involving various parts of the body, including the nucleus accumbens, cerebellum, and hypothalamus of the brain, the nervous system, the circulatory system, and the endocrine glands—as well as the genitals. A meta-study, which combined the results of several studies, of men’s and women’s sexual arousal patterns found that in women, lubrication was only one of the physiological changes that occurred when they were sexually aroused, and not a necessary condition for women to report that they were sexually aroused (Chivers, Seto, Lalumière, & Grimbos, 2010). Much of the science behind sexuality was designed around a very linear model: First, there’s desire, then there’s arousal, followed by orgasms, then snuggling. For most women, this process is more circular, whereby sexuality is about intimacy, relationships, and wanting to cuddle first and feel close to someone. It’s also about how women feel about themselves. If they do not feel desirable or comfortable with their bodies, it’s likely that they will not be able to relax and enjoy the sexual interchange. Among men who have trouble getting erect, genital engorgement is aided by drugs such as Viagra because the pills target genital capillaries. (See Chapter 14 for more information about erection-enhancing drugs.) Thus, the medications may enhance male desire by granting men a feeling of power and control, but not necessarily desire or wanting. For some men, desire is not an issue. In women, the primary difficulty appears to be in the mind, not the body (Brotto, Heiman & Tolman, 2009). Therefore, experimental attempts to use penileenhancing drugs to treat women who complain of low sexual desire have proven ineffective (Bergner, 2010). In both cases, then, the physiological effects of the drugs have proven irrelevant. Some desire is necessary to keep life in “ motion. —Samuel Johnson (1709–1784) The Neural System and Sexual Stimuli The brain is crucial to sexual response and is currently a focus of research to understanding how we respond to sexual stimulation. Through the neural system, the brain receives stimuli from the five senses plus one: sight, smell, touch, hearing, taste, and the imagination. The Brain The brain, of course, plays a major role in all of our body’s functions. Nowhere is its role more apparent than in our sexual functioning. The relationship between our thoughts and feelings and our actual behavior is not well understood (and what is known would require a course in neurophysiology to satisfactorily explain it). Relational factors and cultural influences, as well as expectations, fantasies, hopes, and fears, combine with sensory inputs and neurotransmitters (chemicals that transmit messages in the nervous system) to bring us to where we are ready, willing, and able to be sexual. Even then, potentially erotic messages may be short-circuited by the brain itself, which can inhibit as well as incite sexual responses. It is not known how the inhibitory mechanism works, but negative conditioning and emotions will prevent the brain from sending messages to the genitals. In fact, the reason moderate amounts of alcohol and marijuana appear to enhance sexuality is that they Female Sexual Response • 95 yar35317_ch03_068-104.indd Page 96 6/25/12 7:26 PM user-f502 Women might be able to fake orgasms. “ But men can fake whole relationships. —Sharon Stone (1958–) /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles reduce the control mechanisms of the brain that act as inhibitors. Conversely, women who feel persistent sexual arousal and no relief from orgasm reveal unusually high activation in regions of the brain that respond to genital stimulation (Komisaruk et al., 2010). (See Chapter 14 for a discussion of persistent sexual arousal syndrome.) Anatomically speaking, the part of the body that appears to be involved most in sexual behaviors of both men and women is the vast highway of nerves called the vagus nerve network that stretches to all the major organs, including the brain. Using MRI scans to map the brain, researchers have found increases in brain activity during sexual arousal (Holstege et al., 2003; Komisaruk et al., 2010). Since specific parts of the brain send their sensory signals via specific nerves, the different quality of orgasms that result from clitoral or anal stimulation, for example, is divided among the different genital sensory nerves. As many of us know, the early stages of a new romantic relationship are characterized by intense feelings of euphoria, well-being, and preoccupation with the romantic partner. This was observed in one study in which college students were shown photos of their beloved intermixed with photos of an equally attractive acquaintance (Younger, Aron, Parke, Chatterjee, & Mackey, 2010). Induced with pain during the experiment, students reported their pain was less severe when they were looking at photos of their new love. The test results suggest the chemicals the body releases in the early stages of love— otherwise referred to as endogeneous opioids—work on the spinal cord to block the pain message from getting to the brain. MRI scans showed that, indeed, the areas of the brain activated by intense love are the same areas targeted by pain-relieving drugs. The Senses An attractive person (sight), a body fragrance or odor (smell), a lick or kiss (taste), a loving caress (touch), and erotic whispers (hearing) are all capable of sending sexual signals to the brain. Preferences for each of these sensory inputs are both biological and learned and are very individualized. Many of the connections we experience between sensory data and emotional responses are probably products of the limbic system, or those structures of the brain that are associated with emotions and feelings and involved in sexual arousal. Some sensory inputs may evoke sexual arousal without a lot of conscious thought or emotion. Certain areas of the skin, called erogenous zones, are highly sensitive to touch. These areas may include the genitals, breasts, mouth, ears, neck, inner thighs, and buttocks; erotic associations with these areas vary from culture to culture and from individual to individual. Our olfactory sense (smell) may bring us sexual messages below the level of our conscious awareness. Scientists have isolated chemical substances, called pheromones, that are secreted into the air by many kinds of animals, including humans, ants, moths, pigs, deer, dogs, and monkeys. One function of pheromones, in animals at least, appears to be to arouse the libido. Sensory inputs, such as the sight, touch, or smell of someone we love or the sound of his or her voice, may evoke desire and sexual arousal. 96 • Chapter 3 Hormones The libido in both men and women is biologically influenced by the hormone testosterone. In men, testosterone is produced mainly in the testes; in women, it is produced in the adrenal glands and the ovaries. Growing evidence suggests that testosterone may play an important role in the maintenance of women’s bodies (Davis, Davison, Donath, & Bell, 2005). Although it does not play a large part in a woman’s hormonal makeup, it is present in the blood vessels, brain, skin, bone, and vagina. Testosterone is believed to Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 97 7/27/12 11:21 AM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles contribute to bone density, blood flow, hair growth, energy and strength, and libido. Although women produce much less testosterone than men, this does not mean that they have less sexual interest; apparently, women are much more sensitive than men to testosterone’s effects. Though testosterone decreases in women as they age, the ovaries manufacture it throughout life. Symptoms produced by the decrease of testosterone can be similar to those related to estrogen loss, including fatigue, vaginal dryness, and bone loss. Signs specific to testosterone deficiency are associated with reduced sexual interest and responsiveness in men. The effects of such hormonal changes in women are less predictable (Bancroft, 2009). In spite of widespread claims of testosterone’s effect in treating low sex desire in women, in December 2004, the Food and Drug Administration voted against approval of a testosterone patch, citing concerns about the safety of long-term use of the patch and use by groups that have not been adequately studied. More recently, the balance of evidence seems to show that testosterone replacement therapy for surgically and naturally menopausal women has, if used properly under medical supervision, a more positive effect than a negative one on women (Panzer & Guay, 2009). Though sexual problems, including low libido and/or sexual dissatisfaction, may have physiological causes, they may also be caused by relationship issues, work fatigue, past experiences, or financial problems. It is necessary to look beyond medical solutions when assisting women who have the courage to confront their sexual dissatisfaction. (Testosterone replacement therapy is discussed in Chapter 7.) Estrogen also plays a role in sexual functioning, though its effects on sexual desire are not completely understood. In addition to protecting the bones and heart, in women estrogen helps to maintain the vaginal lining and lubrication, which can make sex more pleasurable. Men also produce small amounts of estrogen, which facilitates the maturation of sperm and maintains bone density. Too much estrogen, however, can cause erection difficulties. Like testosterone replacement, some doctors are also promoting estrogens and bioidentical or natural estrogen supplements to treat conditions caused by estrogen deficiency. The most significant push is aimed at menopausal women. Because no risk-free hormone has ever been identified, claims that human estrogens will protect against cardiovascular effects and other maladies are misleading. While a number of estrogens are effective treatments for hot flashes and vaginal dryness, any health-promotion claims for these drugs are clearly wrong. Shown to be somewhat effective in relieving symptoms associated with some female sexual function difficulties is a botanical called Zestra (Ferguson, Hosmane, & Heiman, 2010). By increasing blood flow and nerve conduction, this product was found to significantly increase clitoral and vaginal warmth, increase arousal, and improve sexual pleasure. Oxytocin is a hormone more commonly associated with contractions during labor and with breastfeeding. It is also increased by nipple stimulation in men and women. This neurotransmitter, which has also been linked to bonding, is released in variable amounts in men and women during orgasm and remains raised for at least 5 minutes after orgasm (Carmichael et al., 1987). It helps us feel connected and promotes touch, affection, and relaxation. Interestingly, oxytocin is important in stimulating the release of all the other sex hormones and, since it peaks during orgasm, it may be responsible for the desire to touch or cuddle after orgasm occurs (Chia & Abrams, 2005). The age of a woman doesn’t mean a “ thing. The best tunes are played on the oldest fiddles. —Ralph Waldo Emerson (1803–1882) Female Sexual Response • 97 yar35317_ch03_068-104.indd Page 98 6/25/12 7:26 PM user-f502 /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles think about it The Role of Orgasm Many of us measure both our sexuality and ourselves in terms of orgasm: Did we have one? Did our partner have one? If so, was it good? Did we have simultaneous orgasms? When we measure our sexuality by orgasm, however, we discount activities that do not necessarily lead to orgasm, such as touching, caressing, and kissing. We discount erotic pleasure as an end in itself. Our culture tends to identify sexual activity with sexual intercourse, and the end of sexual intercourse is literally orgasm (especially male orgasm). An Anthropological and Evolutionary Perspective A fundamental, biological fact about orgasm is that male orgasm and ejaculation are required for reproduction, whereas the female orgasm is not. The male orgasm is universal in both animal and human species, but sociobiologists and anthropologists have found immense variation in the experience of female orgasm. Anthropologists such as Margaret Mead (1975) found that some societies, such as the Mundugumor, emphasize the female orgasm but that it is virtually nonexistent in other societies, such as the Arapesh. In our culture, women most consistently experience orgasm through a combination of vaginal intercourse and manual and oral stimulation of the clitoris. In cultures that cultivate female orgasm, according to sociobiologist Donald Symons (1979), there is, in addition to an absence of sexual repression, an emphasis on men’s skill in arousing women. In our own culture, among men who consider themselves (and are considered) “good lovers,” great emphasis is placed on their abilities to arouse their partners and bring them to orgasm. These skills include not only penile penetration but also, often more importantly, clitoral or G-spot stimulation. This, of course, is based on the sexual script that men are to “give orgasms to women,” a message that places pressure on men and that tells women they are not responsible for their own sexual response. According to this script, the woman is “erotically dependent” on the man. The woman can, of course, also stimulate her own clitoris to experience orgasm. Because it is closely tied to reproduction, evolutionary scientists have never had difficulty explaining the male orgasm; it ensures reproduction. In the same vein, scientists have for decades insisted on finding an evolutionary function for female orgasm but have not been as successful. Possibly, one effect of orgasm is to increase a suction in the uterus to draw up ejaculated semen thereby increasing the retention of sperm (Komisaruk et al., 2010). Since women can have sexual intercourse and become pregnant without experiencing orgasm, perhaps there is no evolutionary function for orgasm (Lloyd, 2005). However, philosopher and professor Elisabeth Lloyd acknowledges, evolution does not dictate what is culturally important. In reviewing 32 studies conducted over 74 years, Lloyd found that when intercourse was unassisted—that is, not accompanied by stimulation of the clitoris—just one quarter of the women studied experienced orgasms often or very often and a full one third never did; the rest sometimes did and sometimes didn’t. The Tyranny of the Orgasm Sociologist Philip Slater (1974) suggests that our preoccupation with orgasm is an extension of the Protestant work ethic, in which nothing is enjoyed for its own sake; everything is work, In spite of what we do know about the importance of biological influences on sexual desire and performance, when biological determinants or evolutionary accounts are given undue weight and psychosocial forces are ignored or minimized, a medical model that negates the significance of culture, relationships, and equality can emerge (Lloyd, 2007; Wood, Koch, & Mansfield, 2006). “ Those who restrain desire do so because theirs is weak enough to be restrained. —William Blake (1757–1827) 98 • Chapter 3 Experiencing Sexual Arousal For both males and females, physiological changes during sexual excitement depend on two processes: vasocongestion and myotonia. Vasocongestion is the concentration of blood in body tissues. For example, blood fills the genital regions of both males and females, causing the penis to become erect and the clitoris to swell. Myotonia is increased muscle tension accompanying the approach of orgasm; upon orgasm, the body undergoes involuntary muscle Female Sexual Anatomy, Physiology, and Response yar35317_ch03_068-104.indd Page 99 6/25/12 7:26 PM user-f502 including sex. Thus, we “achieve” orgasm much as we achieve success. Those who achieve orgasm are the “successful workers” of sexual activity; those who do not are the “failures.” As we look at our sexuality, we can see pressure to be successful lovers. Men talk of performance anxiety. We tend to evaluate a woman’s sexual self-worth in terms of her being orgasmic (able to have orgasms). For men, the significant question about women’s sexuality has shifted from “Is she a virgin?” to “Is she orgasmic?” Pretending Orgasm The idea that women “fake” orgasms is familiar, probably because there is considerable pressure on them to do so. What is less well-known is that some men also pretend orgasm. Research on pretending orgasm can provide interesting insights into sexual scripts and their functions and meanings for both sexes (Muehlenhard & Shippee, 2009). Researchers and professors Muehlenhard and Shippee found that 25% of men and 50% of women reported pretending orgasms, but that these rates were even higher for those who had experienced penile-vaginal intercourse. Frequently reported reasons for pretending orgasm (reported by both sexes) were that orgasm was unlikely, they wanted sexual activity to end, and they wanted to avoid negative consequences (hurting their partners’ feelings) and obtain positive ones (pleasing their partners). Both men’s and women’s narratives suggested a common sexual script in which the woman should orgasm first, ideally during intercourse, and when the man orgasms, sex is over. Thus, the researchers conclude, “It seems that much of people’s sexual behavior is guided by their or their partners’ scripts and expectations—even if this requires pretending.” Such questions are often asked by men rather than women, and women tend to resent them. Part of the pressure to pretend to have an orgasm is caused by these questions. What is really being asked? If the woman enjoyed /Volume/207/es/MH01875/yar35317_disk1of1/0078035317/yar35317_pagefiles intercourse? If she thinks the man is a good lover? Or is the question merely a signal that the lovemaking is over? “Was It Good for You?” A question often asked following intercourse is “Was it good for you?” or its variation, “Did you come?” While the question “Was it good for you?” may initiate a dialogue, the statement “Orgasm is good for us” acknowledges a fact. Though it’s apparent that orgasm feels good, some of us may not recognize that orgasm is indeed good for our health. Sexual activity not only burns quite a few calories and boosts the metabolism, it also improves immune function, helps you sleep better, and relieves menstrual cramps and stress. In fact, substantial connections between women’s sexual satisfaction and all three aspects of their well-being (relational, mental, and physical) have been reported (Holmberg, Blair, & Phillips, 2010). Though we don’t yet understand all of the benefits of sex and orgasm, there is mounting evidence that the enjoyment we receive from sex moderates our hormones and improves our emotional state. Think Critically 1. How important is it that each partner experience orgasm? What (if anything) would you say to a sexual partner who never or rarely experiences one? 2. Do you believe there are differences in the amount of ...
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Topic: Human sexuality writing assignment
Question #1
The context Perspectives on Human Sexuality focuses on various life aspects that are
influenced by human sexuality. Human sexuality defines the ability to have sexual feelings or
sexual orientation (Bolin and Whelehan, 1999). Reflecting on the context, the use of
smartphones by young persons should be regulated. Smartphones support the major media
platforms that perpetrate popular culture amongst the population. The internet is one of the most
mover controlling more than two-thirds of the global population. There is a need to educate
young people on the right morality before giving them smartphones. Moral education would
prepare the teens in choosing the right content to watch in the pool of smartphone entertainment.
Peers are greatly influenced by media. Many young people are socially connected to peer
groupings. Peer groups have a lot of social pressure. I have formulated opinions on the various
sexual matter as I grew up. For example, I have grown up knowing that kissing is a normal
sexual matter. I have seen many people kiss publicly as I grew up.
Question #2
The chapter, Female Sexual anatomy, physiology, and response, addresses the biological
functionality of female and male reproductive systems (Bolin and Whelehan, 1999). Women
must have the menstrual flow control products of their choice during menstruation. The latter
products are different; some are environment-friendly, while others are not. Most commercial
products are not environmentally friendly. In my account, orgasm is the peak of sexual pleasure
due to maximum sexual stimulation of a sexual organ. It is the feeling of unconsciousness,

involuntary, and uncontrollable satisfaction that flushes through the entire body due to sexual
stimulation (Bolin and Whelehan, 1999). Conclusively, I have a positive response when I look at
my genitals. There is nothing extraordinary with my genitals, and therefore, I have nothing to
worry about. Most ladies may dislike the shape of their vagina lips or the general sexual organ
anatomy. The latter may lead to low self-esteem. I am very comfortable to look at my genitals; I
do self-examination regularly.
A. Conclusion
B. References


Running head: HUMAN SEXUALITY WRITING ASSIGNMENT

Human sexuality writing assignment
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HUMAN SEXUALITY WRITING ASSIGN...


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