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Chapter 4: Sexual Anatomy and Physiology Learning Objectives Sexual Anatomy • Understand why it is important to know about the sexual body. Female Sexual Anatomy • Identify the structures of the female reproductive system. • Discuss the variability in appearance of female genital structures. • Understand what female genital mutilation is and why it is performed in certain cultures. Female Sexual Physiology • Understand the role of the endocrine system in sexual physiology. • Identify the major hormones that play a role in the functioning of the reproductive system. • Describe the role pheromones play in sexual behavior and menstrual synchrony. • Discuss the process of menstruation and what happens in menopause. Male Sexual Anatomy • Identify the structures of the male reproductive system and understand how the male reproductive system functions. • Discuss the variability in appearance of male genital structures. • Discuss the process of circumcision and how it affects the physical structure of the penis and the male sexual experience. • Understand why individuals circumcise their own or their children’s genitals. Male Sexual Physiology • Compare the hormonal cycle of men to the female menstrual cycle and menopause. Bodily Integrity Rights and Sexual Well-Being • Apply the concept of bodily integrity rights to female genital mutilation and circumcision. Chapter Outline Chapter 4: Sexual Anatomy and Physiology Learning Objectives 4.1 Discussion Topic 4.1 Learning Objectives 4.2 Discussion Topic 4.2 Discussion Topic 4.3 Learning Objectives 4.3 Discussion Topic 4.4 Discussion Topic 4.5 Discussion Topic 4.6 Discussion Topic 4.7 Learning Objectives 4.4 Discussion Topic 4.8 Discussion Topic 4.9 Learning Objectives 4.6 Discussion Topic 4.10 I. Sexual Anatomy • Anatomy is the study of the physical structure of our bodies and the intricate design of the systems that live within the structures, for example, the respiratory, circulatory, nervous, endocrine, and reproductive systems. • Physiology is the study of how all these internal systems and structures function. II. Female Sexual Anatomy A. External Female Sex Organs • The term for the female external genital region is the vulva, though it is often mistakenly called the vagina. The vagina is an internal organ that lies just inside the vulva. Figure 4.1 shows the structures of the vulva. • The mons pubis (mons veneris) is the fatty tissue overlying the pubic bone. After the onset of puberty, this region is generally covered with pubic hair. • Part of the vulva is the labia majora. The labia majora are vertical liplike structures of skin folds that cover the labia minora; and like the mons pubis, the outside of the labia majora is generally covered with hair after puberty. • The labia minora are also liplike structures that comprise smaller and more delicate skin folds. Unlike the labia majora, the labia minora are hairless, although they contain numerous sebaceous glands that resemble small bumplike structures. During sexual arousal, blood rushes into the vascular tissue of the labia in a phenomenon known as tumescence. • The folds of the labia minora connect at the top of the vulva to the clitoral hood, which covers the clitoris. Unlike the male penis, which serves as the organ of sexual pleasure, reproduction, and urination, these functions are all separate in the female. • The sole function of the clitoris is to produce pleasure and thus it contains numerous nerve endings that render it the most sexually sensitive organ in the female body. In comparison to the male penis, the clitoris contains more nerve endings in its pea-shaped glands than are found in the entire head or glands of the penis. • In its unaroused state, the clitoris is retracted under the clitoral hood. However, during sexual arousal and tumescence, the clitoris becomes stiff and erect causing the clitoral hood to pull back. • The clitoris is primarily an internal structure with only a small area, the clitoral glans, being visible. The internal part of the clitoris is shaped like an inverted V, forming two legs that extend from the clitoral glands along both sides of the labia. o These legs are called the clitoral crura and are made up of spongy tissue that will engorge with blood during sexual arousal. • Below the clitoris is the urethral opening where women expel urine from the bladder. The vaginal opening, found between the urethra and the anus, extends into the vagina. • The vagina is an elastic canal, which, with sexual arousal, will increase in length and width. The vaginal wall’s increase in size during sexual arousal is called the tenting effect. • The inner wall of the vagina is made up of moist, soft tissue called mucous membrane. Mucous secretions help to keep the vagina clean by producing a balanced solution of acid-alkaline. o During sexual arousal these secretions will increase and the Bartholin’s glands, located on each side of the vaginal opening, will begin to produce vaginal lubrication. The inner vagina is also the location of the highly debated G-spot. Controversies in Sexuality The Elusive G-Spot • Students many have seen stories in magazines like Cosmopolitan that discuss how can experience greater orgasmic potential by locating their G-spot. • Some sexual scientists dispute its existence or importance, but still, many women endorse the G-spot as their source of potential pleasure and orgasm. • The G-spot, or Grafenberg spot, is located approximately 2 inches up the anterior vaginal canal (Figure 4.2). • During sexual arousal, vasocongestion, or increasing blood flow to erectile tissues in the genitals and nipples, occurs and the nerve endings surrounding the G-spot allegedly can be stimulated enough to produce an orgasm. • Although some women have had their G-spot surgically enlarged to intensify orgasm, to the benefit of plastic surgeons, the evidence for the existence of the G-spot remains sketchy. B. Internal Female Sexual Organs • The internal female sexual organs, illustrated in Figure 4.3, include the vagina, the cervix, the uterus, and the fallopian tubes, as well as the introitus and hymen. The vagina is a potential space for penile penetration. o It is also the birth canal and the place where the menstrual blood leaves the body. The inner part of the vagina is connected to the cervix, which opens into the uterus. • Also called the womb, the uterus is connected at one end to the cervix and on both sides to the fallopian tubes. The conelike cervix rests on the top of the vagina. • During heterosexual intercourse, semen may be delivered right into the entrance to the cervix, increasing the likelihood for sperm to travel up through the cervix and into the uterus and the fallopian tubes (also called uterine tubes), where fertilization may take place. • The opening of the vagina, called the introitus , is located between the urinary opening and the anus. The hymen is a fold of tissue that, in most women, partially covers the introitus. o The hymen is typically present at birth, although some females have no hymen at birth, and stays intact until penetration by the penis or some other object, or is torn in some other way. The hymen, like other sexual structures, varies in shape and size among females (Figure 4.4). o In the rare case of an imperforate hymen, the tissue of the hymen completely closes the vaginal opening causing menstrual fluid to accumulate. This condition requires a small incision to open the hymen. • The uterus is a muscular pear-shaped organ that connects to the fallopian tubes, one on each side. Three layers comprise the uterine walls: the perimetrium, which is the outermost part; the myometrium, or the muscular middle layer; and the endometrium, or the innermost layer, into which a fertilized ovum will implant. • The fallopian tubes are approximately 7 to 14 cm (2.76 to 5.5 inches) long. Each one ends in a fringe of tissue called the fimbria, which sweeps over the ovaries during ovulation (the phase of a woman’s menstrual cycle in which an egg is released), picks up the ovum, and, with the help of tail-like projections inside the walls of the fallopian tubes, guides the ovum down to the uterus. • Figure 4.5 shows the structure of the ovary and other parts of the reproductive system. The ovary resembles an almond in size and shape and has two main functions: to release ova (eggs) and to produce hormones. o Most females have two ovaries in the pelvic cavity on each side of the uterus. Every month during ovulation, either the right or left ovary produces a single mature egg for fertilization. o When a baby girl is born, she already has about 1 million ovarian follicles, each containing a hollow ball of cells with an immature egg in the center. During childhood, approximately half of ovarian follicles are absorbed by the body. o Unlike men who produce sperm throughout most of their lifetime, women are born with all the ova they will ever have. During the reproductive years, the time between puberty and menopause, the ovaries may release 300 to 500 mature ova. C. Breasts and Breast Development • Though the breasts are often sexualized, they are not part of the female genitalia. Rather, they are secondary sex characteristics that develop as a girl matures. • The mammary glands and fat deposits primarily comprise the internal breast, whose principal function is to produce milk to nourish an infant after childbirth. Externally, the areola is the dark center of the breast and the nipple is the raised bud at the center of the areola. • Figure 4.6 shows the structure of the breasts. Breast development is often the first thing that young girls experience in puberty. • Thelarche is the name for the first stage of breast development, characterized by a small lump that forms beneath the areola. In puberty the ovaries begin to produce greater amounts of estrogen, a hormone that produces female reproductive and secondary sex characteristics and influences the menstrual cycle. • At menarche, or a female’s first menstrual period, secretory glands form at the end of the milk ducts and they continue to mature. • Maintaining breast health is an important part of female health care. One of the ways to do this is to self-examine the breasts monthly for changes, lumps, or secretions from the nipples. D. Variability in the Female Body • Though the descriptions of female sexual anatomy and secondary sex characteristics have been very general, it’s important to note that not all female bodies look the same. In fact, all bodies vary in some way. • These variations are most evident in the size, shape, and color of our bodies. But bodies often differ anatomically. • Most cultures have standards of female beauty to which many women aspire. For example, in some West African cultures, such as Nigeria, large buttocks, breasts, and curvaceous hips are the epitome of female beauty. • The size, shape, and weight of bodies are sources of anxiety for many people in the United States. Recognizing the natural variability in bodies helps in understanding that, despite what might be narrow standards of beauty, individuals have the right to know about their bodies, to keep them healthy and to seek pleasure in safe and satisfying ways. • In the United States, modification is considered to be an elective procedure; however, in many areas of the world, genital modification is a cultural practice. Rituals such as female circumcision, or female genital mutilation, have critical and important consequences to the sexual health and well-being of those who are subjected to them. E. Female Genital Mutilation • Female circumcision is a cultural practice most often associated with African and Middle Eastern cultures, and the Islamic religion in particular. Some cultures believe that removal of the clitoris enhances the beauty and desirability of the female body, and others are also taught that unless the clitoris (the major source of sexual pleasure for women) is removed, women may become promiscuous or unfaithful to their partners. • The most severe degree of female circumcision involves completely removing the clitoris and labia minora and scraping the labia majora. Any remaining tissues are then sewn together, leaving only a very small hole to allow the menstrual blood and urine to pass. o This may also prevent a female from having sexual intercourse or having her hymen ruptured. When she marries, the stitches are either removed before her first night with her husband or broken apart when she and her husband have intercourse for the first time. o Because this procedure is often performed without antiseptic or anesthesia, some people refer to it as female genital mutilation (FGM). According to WHO (2012), FGM is most common in 28 countries in Africa, in parts of the Middle East, and among migrants from these areas. III. Female Sexual Physiology • Sexual physiology refers to the way that anatomical structures work during sexual development and sexual response. • Sexual physiology happens in tandem with our interactions in the social world, rather than in isolation and in response only to biological directives. A. The Endocrine System and Hormones • The endocrine system is the system of glands that regulates body functions and processes, including puberty, metabolism, and mood, by releasing chemical substances called hormones. The endocrine system includes the hypothalamus, the area of the brain that secretes substances that influence the function of the pituitary and other endocrine glands and is involved in the control of the body temperature, hunger, thirst, and other processes that regulate body equilibrium. • The pituitary gland is a pea-sized gland located at the base of skull that is sometimes referred to as the “master gland,” because it controls the hormone functions mentioned above and regulates growth. • The endocrine system also regulates important parts of sexual development and arousal, pregnancy and menstruation, and sperm production. • The two primary hormones regulating sexual development and arousal are androgens and estrogens, which belong to a class of hormones called steroid hormones. The gonads, or glands that produce sex hormones and reproductive cells (i.e., ovaries in women and testes in men) and the adrenal glands located on top of the kidneys secrete the steroid hormones. • Though females produce greater amounts of estrogens, they also produce androgens, and though male bodies produce greater amounts of androgens, they also produce estrogens. • Testosterone is a steroid hormone from the androgen group that has been shown through research to have a greater effect on male sexual desire than on function. Testosterone is also known to play a primary role in female sexual drive. • Estrogens and their roles in female sexual behavior are less clear. Research has shown that estrogens contribute to vaginal lubrication, to maintenance of the thickness and elasticity of the vaginal walls, and to a general sense of well-being. • Another class of hormones, the neuropeptide hormones, influences the emotional aspects of sexuality, including attraction and arousal. Oxytocin is one of the most important neuropeptides. o Oxytocin may influence our feelings of erotic attraction and love. It serves many purposes, including facilitating the flow of milk during breastfeeding, elevating our feelings of love and attraction while we cuddle, and helping us form strong emotional bonds with those to whom we’re close. B. Pheromones and Their Role in Sexual Behavior • Pheromones are chemical signals that are not readily noticed by human senses, but are released by organisms to effect a behavioral or psychological response in another body. Females in many animal species release pheromones during the fertile period of their menstrual cycles to signal their availability for reproduction. • Males may secrete pheromones that convey information about their genes, perhaps indicating health status or longevity or some other characteristic necessary for the survival of that particular species. • Research on the presence of pheromones in humans is inconclusive, though some studies suggest that certain scents can activate or inhibit sexual attraction and arousal. One study suggests that women who live together may menstruate at the same time, a phenomenon known as menstrual synchrony, based on odor cues. C. The Menstrual Cycle • Menstruation, the shedding of the uterine lining, is one of the most significant physiological processes of the female body. During each menstrual cycle, the lining of the uterus is prepared to nourish a fertilized ovum. • If conception occurs, the ovum will implant in the uterus and the uterine lining will not be shed. If conception does not occur, the uterine lining is shed and exits the body through the vagina. o This shedding process is what is referred to as a woman’s period. The menstrual period generally lasts 2 to 6 days and may produce up to 8 ounces of menstrual flow. • Throughout the cycle, the uterus passes through three phases in preparation for the implantation of a fertilized ovum (Figure 4.8). o The first phase begins during ovulation and is called the proliferative phase. During this phase, the endometrium of the uterus thickens and the ovum matures. o In the next stage, the secretory phase, the endometrium further thickens and the corpus luteum develops. This is the tissue formed from a ruptured ovarian follicle after the release of the ovum. The corpus luteum produces important hormones, including progesterone, which prepares and maintains the uterus for pregnancy. o In the third and final phase, the menstrual phase, the ovum has passed through the fallopian tube and into the uterus. Unfertilized, it dissolves and the uterus sheds the endometrium through the cervix as menstrual flow. • During puberty the ovaries begin to produce greater amounts of estrogens. This increase in estrogens signals the hypothalamus to release gonadotropin-releasing hormone (GnRH). o GnRH stimulates the pituitary gland to release two hormones called luteinizing hormone (LH) and follicle stimulating hormone (FSH), which triggers menstruation. When LH is released into the body, the body produces greater amounts of progesterone to suppress LH. o If fertilization does not occur, the rising level of progesterone inhibits the release of GnRH which, in turn, inhibits further production of progesterone. As the progesterone level drops, the corpus luteum begins to degenerate; the endometrium begins to break down, the inhibition of uterine contractions is lifted, and the bleeding and cramps of menstruation begin. o Table 4.1 shows the descriptions of these important hormones and their roles in human sexual and reproductive lives. • Because the menstrual process is a complex interplay of hormones that have secondary effects on the body, a number of complications may arise during the phases of a woman’s menstrual cycle. One of them is premenstrual syndrome (PMS). • The range of the symptoms of PMS is so broad—from cramps, to nausea, to pain, to depression, to cravings—the exact causes of the wide variation of PMS symptoms are unknown. Several factors, primarily hormonal fluctuations and interactions with neurotransmitters (chemical messengers in the brain) are suspected. • Estimates of the number of women who suffer from PMS vary widely. For example, the American Congress of Obstetricians and Gynecologists estimates that at least 85% of menstruating women have one or more PMS symptoms during their monthly cycle. o Most women’s symptoms are mild and do not require medical treatment. However, about 3–8% of women endure more severe symptoms and have a condition called premenstrual dysphoric disorder (PMDD). o Women with PMDD often report that they feel “out of control” during the time right before their period begins. Symptoms include markedly depressed mood, increases in anxiety, and significantly decreased interest in activities. • Another complication that may arise during menstruation is dysmenorrhea, severe uterine pain during menstruation. Compounds called prostaglandins are released during menstruation and cause inflammation in the uterus, making it contract to shed the endometrium. o The uterine contractions and the oxygen deprivation of nearby tissues cause the painful cramps of dysmenorrhea. In some cases, dysmenorrhea may signify the presence of uterine fibroids or endometriosis. • Another condition, amenorrhea, refers to the absence of menstrual periods. States of amenorrhea are completely natural in many women’s lives, particularly during pregnancy and after menopause. o Primary amenorrhea is the term used when a young woman has never had a period, usually by the age of 16 in the United States. o Secondary amenorrhea describes a disruption in a previously normal menstrual cycle, often because of disturbances in the hypothalamus or pituitary gland. Other causes of secondary amenorrhea are extreme weight loss caused by eating disorders, excessive stress or exercising, and weight loss that occurs as a result of a serious illness. • One last menstrual concern is toxic shock syndrome (TSS). Toxic shock syndrome is a rare but severe infection that involves fever, shock, and problems with the function of several body organs. o TSS can be fatal if not treated promptly. TSS is caused by a toxin produced by certain types of bacteria. o Risk factors for TSS include: Childbirth Presence of a staph infection Menstruation Surgery of any type Tampon use (particularly if they are left in the vagina for an extended period of time) Using barrier contraceptives such as a diaphragm o Symptoms of TSS include confusion, diarrhea, headaches, high fever, low blood pressure, muscle aches, nausea and vomiting, organ failure, and a widespread rash that looks like sunburn particularly on the palms of the hand or the bottom of the feet. • Any menstrual problems that are unusual or concerning should be brought to the attention of a health care provider. Specifically, if a woman experiences one of the following menstrual problems, she should contact a health care provider: o Menarche has not occurred by the age of 16 o The menstrual period has suddenly stopped o Menstrual bleeding is excessive o Severe pain occurs during menstruation D. Menopause • Menopause is a time in a woman’s life when menstruation eventually stops and the body goes through changes that no longer allow her to get pregnant. It generally occurs when women are in their mid-40s to early 50s. • While the term menopause actually refers to a specific date—the last menstruation—the time around menopause when the female body is undergoing changes associated with menopause is known as perimenopause. • During perimenopause, the amounts of estrogen, progesterone, and testosterone that the body produces begin to diminish. Once the ovaries have stopped releasing ova each month, the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the body increase. o This fluctuation in hormones leads to changes in the body, the most notable of which is the hot flash, during which the body’s temperature rapidly increases and then returns to normal. • When a woman goes 12 months without ovulation, she has reached menopause. Many women elect hormone replacement therapy (HRT) to offset some of the effects of decreased natural levels of hormones associated with menopause. o There are various types of hormone replacement therapies that target certain effects of menopause, one particular concern being osteoporosis, or abnormal bone loss. IV. Male Sexual Anatomy A. Structures of the Male Reproductive System • The primary organ for male sexual pleasure, the penis contains many sensitive nerve endings. Contrary to popular belief, the penis is not a muscle. o However, the base of the penis, called the root, connects to several muscles and pelvic structures. During an erection—the firm and enlarged condition of a body organ or part when the erectile tissue surrounding it becomes filled with blood, especially such a condition of the penis or clitoris—the penis is stabilized by the muscles at the base of the penis. • Besides the root, the penis contains a number of other structures (Figure 4.9). The penile shaft contains three tubular cylinders, which are made out of smooth spongy tissue. • The inside, hollow tissue of the penis is called the corpus cavernosa and the erectile tissue surrounding the urethra is known as the corpus spongiosum. During sexual arousal, this spongy tissue becomes engorged with blood, making the penis erect. • The urethra, which transports urine and semen, runs through the corpus spongiosum and ends at the penile glans found at the very top of the penis. The glans of the penis is a very sensitive area containing many nerve endings. • The rounded base of the penile glans is called the corona, which is the most sexually sensitive part of the penis. • On an uncircumcised man, the foreskin covers the penile glans. If uncared for, the glans of an uncircumcised penis produces secretions that accumulate beneath the foreskin, forming a smelly and cheesy substance called smegma. • The frenulum is an elastic fold of tissue connecting the penile glans with the foreskin and the shaft of the penis (Figure 4.10). This area is also highly sensitive. • The scrotum is located between the penis and the anus and is an extension of the abdomen. The scrotal sac, which holds the testicles, or testes, is a delicate layer of skin that contains numerous sweat glands and hair follicles. • During puberty, pubic hair appears in this area and the surrounding area of the penile root. Figure 4.11 shows the location and structure of the testicles. • Testicular cancer affects more young men than any other type of cancer. For this reason, it is important for males to perform a testicular self-exam regularly. B. Internal Male Sex Organs • The testicles, or testes, are the male gonads and have two primary functions: the production of the hormone testosterone and of sperm. The testes need to be kept 1 to 2 degrees below the normal body temperature of 98.6 8 F for sperm production. • The cremaster muscle in the scrotum helps to maintain the ideal temperature for sperm production no matter the climate. In hot climates, it lowers the testes away from the body to reduce their temperature; and in cold climates, it pulls them up closer to the body to increase their temperature. • The process of sperm production, known as spermatogenesis, takes place inside the testicle in a tubular structure called the seminiferous tubule (Figure 4.12). The seminiferous tubules are tightly coiled into a capsule called tunica albuginea, giving the structure the appearance of a cross section of a grapefruit. • Upon leaving the seminiferous tubules, the sperm enter the epididymis. The epididymis is also a tightly coiled tubular structure that connects the testes with the vas deferens, a duct connecting the testicles with the urethra. C. Erection and Ejaculation • During sexual arousal, nerve impulses from the brain travel down to the erection centers on the spinal cord. The production of nitric oxide signals the smooth muscle tissue in the penis to relax, which allows blood to enter the penile columns or erectile tissues. o This smooth muscle tissue in the corpus cavernosa and corpus spongiosum engorges with blood and an erection occurs, a phenomenon called tumescence. With penile erection, the muscles just below the surface of the perineum, the area of skin between the scrotum and the anus, contract and help to stabilize the penis. • During ejaculation, an autonomic nervous system reaction, the sperm leave the epididymis, move through the vas deferens, and are expelled from the body through the urethra. This constitutes an orgasm for the male. • As the sperm leave the vas deferens and enter the urethra, secretions from the seminal vesicles and the prostate gland are added to the sperm. The resulting fluid mixture is called semen. • The prostate gland, located just beneath the bladder (Figure 4.9), surrounds the urethra and is responsible for the creation and storage of semen. About 70–75% of semen is made up of secretions from the seminal vesicles, about 20–25% comes from the prostate gland, and 1% consists of sperm. • During the earlier stages of sexual arousal there is a small secretion of clear fluid from Cowper’s glands (also known as the bulbourethral glands; Figure 4.9), which helps to clear out and lubricate the urethra in preparation for ejaculation. • The process of ejaculation occurs in two stages: the emission phase and the expulsion phase. o During the emission phase, the cremaster muscle pulls the testes up close to the body preparing to release sperm. Semen is prepared for secretion and the man feels that he is about to ejaculate or “come.” This part of the ejaculation process is known as ejaculatory inevitability. o As the expulsion phase begins, rhythmic contractions of smooth muscles and tissue in the epididymis, vas deferens, seminal vesicles, ejaculatory ducts, prostate gland, and urethra force semen out of the body. After the semen has been ejaculated, the penis becomes soft and loses its erection, a state called detumescence. • For a period of time after resolution, regardless of further sexual stimulation, the penis will not become erect. This unresponsive time is called a refractory period. D. Variability in the Male Body • Like the female body, the male body varies in shape, size, color, and function. For example, some men are born with one testicle; other men may develop large, pronounced breasts. • As standards of female beauty differ by culture, so do standards of male beauty. Many cultures value men for their physical stature and equate power and influence with men who are tall and muscular. • Penis sizes vary, but when penises are erect, they are all about the same size. The biggest difference in size is in the flaccid, or unaroused, penis. o It averages about 3 inches in length and varies between 1 and 4 inches for most men, as measured in many scientific studies from locations as diverse as the United States, Germany, Nigeria, Iran, and South Korea. The small, flaccid penis appears to be at the root of men’s insecurity about penis size, the so-called locker-room syndrome. o Flaccid length does not predict erect length, however, and most of the variation disappears in an erect penis. Most penises measure between 5 and 6 inches in length when erect, regardless of the size of the flaccid penis. • Experts have repeatedly shown that size is not the critical variable in sexual pleasure and fulfillment. For heterosexual intercourse, an erect penis longer than 4 inches is usually big enough to stimulate erogenous tissue in a woman’s vagina. o Most of the nerve endings relating to sexual pleasure in a woman’s vagina are located within the first one-third of the length of the vagina. This means that most penises are capable of stimulating these nerves and providing pleasure during coital activities. o A penis that is too big can actually cause difficulties: one that is longer than 8 inches can hit a woman’s cervix and cause her discomfort. Healthy Sexuality Penile Enhancement Techniques • Throughout history and across cultures people have clung to the fascinating attitudes about what makes the perfect penis, and especially what makes for greater sex appeal and pleasure. • There has been attention in the media, medicine, and popular culture paid to penis modification, the counterpart to plastic surgery in women used to enhance sex appeal. • Because of medical advances, what we once thought was fixed for life can now be surgically altered. o The penis is no different, and in fact, there is evidence that all kinds of new procedures, such as penile implants, which are objects or substances inserted into the penis to increase size and pleasure, are increasing. o The implants include plastic beads, metal ball-bearings, palm oil, soft plastic, metal clasps, and other more exotic items. o Many men do report subjectively that they and their sexual partners experience greater sexual pleasure following these operations, but there may be significant medical complications and possible side effects. o Potential side effects include having a permanent erection (depending on the type of procedure or implant), which can be bothersome, create an abnormal feel and appearance of the penis, and cause possible deterioration and thinning of the penile flesh over time. • Penile surgery has helped men who truly need it. o Men who are born with a congenital abnormality, who have suffered an injury, or who have severe difficulties achieving erections may seek and receive surgery. • Penis enlargement surgery is risky enough that a man may lose sensation or the ability to have an erection. o Doctors do try to dissuade men from these procedures through counseling and a frank discussion of the facts. o One surgical method to enlarge a penis is to transfer fat to add to girth. This often leads to lumping and a distorted penis shape over time. o Another technique involves the release of the suspensory ligament, the ligament that helps retract and release the penis into the body, often resulting in infection, loss of sensitivity, and erectile dysfunction, the inability to gain or sustain an erection. E. Circumcision • Male circumcision, usually performed on infant boys, involves entirely or partially removing the foreskin (Figure 4.13). In the United States and other countries, circumcision is a common type of genital modification. • It is an ancient practice known in many cultures, although in recent years, people have begun to question the procedure, and it has been the focus of increasing controversy. • Though normal male genitals are fully functional just as they are, some cultures have developed rituals for modifying genitals to express religious conviction, to make a moral statement, or to improve hygiene. • In the twenty-first century, male circumcision is very unusual in Western Europe and increasingly questioned by pediatricians in the United States, although it continues to be practiced. There is no medical consensus about its benefits, however. o In fact, there are actually individuals and organizations that now actively oppose this practice. For example, the American Academy of Pediatrics (1999) states that there is not enough evidence to endorse infant circumcision and advises parents to make up their own mind in consultation with their pediatrician. • Some public health advocates have campaigned to make male circumcision widespread in developing countries with high HIV and STI rates, particularly in Africa. According to this recommendation, removing the foreskin decreases the likelihood that bacteria will accumulate under the foreskin, thereby reducing the spread of bacteria and viruses to sexual partners. o There is evidence for circumcision protecting against HIV/AIDS, but it is weak and thus its use to curtail the spread of HIV/AIDS remains controversial. For example, circumcision decreases risk for males, not for female partners in vaginal sex, and anal sex risk protection is unknown. V. Male Sexual Physiology • During adolescence, the testes begin to produce greater amounts of testosterone, which promotes the maturation of the male sex organs and secondary sex characteristics, such as the growth of body hair. In later life, a process similar to menopause, called andropause, occurs in some men, as decreasing levels of testosterone slow the desire for sex and reduce the depth of sensation in the genitals. o These changes sometimes contribute to erectile dysfunction. While the circulating levels of testosterone decreases in most men, not all men experience the same effects. VI. Bodily Integrity Rights and Sexual Well-Being • The topics of female genital mutilation and male circumcision relate directly to the issue of bodily integrity rights. The concept of bodily integrity refers to the inviolability of the physical body. o It emphasizes the importance of personal autonomy and the self-determination of individuals over their own bodies. It considers the violation of bodily integrity as an unethical infringement, intrusive, and possibly criminal. • Experts say that decisions involving bodily integrity rights should be an individual choice, and if it pertains to a child, the family should wait until the child is old enough to make his or her own decision. Bodily integrity rights cover circumcision, genital surgery, genital cutting, cosmetic surgery, and all aspects of how people present themselves to the public. • Because cultures vary widely in values about personal appearance and taboos about the body, it is not surprising that bodily integrity raises many controversies. Throughout the global community today there is increasing concern about how cultures tamper with human anatomy, both female and male. • Some people, including experts on the topic, feel that the genitals are so basic to our sense of who we are as men and women that any alteration to them through surgery or hormones or other means is a direct assault. One form of bodily integrity is genital integrity, the idea that someone’s genitals ought to be left intact and not be interfered with by anyone. o Genital integrity would leave the choice to modify the genitals to the individual woman or man. • It is important to understand that female genital mutilation is not a universal procedure—it is certainly not as widely practiced as male circumcision. • In the United States, some laws prohibit the genital modification of female minors, unless medically necessary. • Opponents of male circumcision assert that laws against genital modification of minors should apply equally to males and females. • Many authorities believe that male circumcision and female genital mutilation are very different and should not be lumped together. Key Terms Anatomy—the study of the physical structure and systems of the body Physiology—the study of how bodily structures and systems function Vulva—the external female genitals; often referred to as the vagina Mons pubis—also called the mons veneris, the female pubic mound; the fatty tissue that covers the pubic bone Pubic bone—part of the pelvis, the pubic bone is covered by a layer of fat known as the mons pubis Labia majora—the outer lips of the vulva Labia minora—the inner lips of the vulva, one on each side of the vaginal opening Sebaceous glands—glands that produce oil Tumescence—the state of being swollen or engorged with blood Clitoral hood—the fold of skin that surrounds and protects the clitoral glans Clitoris—a highly sensitive structure of the female external genitals Clitoral glans—the small external portion of the clitoris Clitoral crura—the internal portion of the clitoris G-spot—the Grafenberg spot, an area of the vagina that is potentially erogenous and is thought to produce powerful orgasms Vasocongestion—an increase in blood flow to erectile tissues in the genitals Urethral opening—opening between the clitoris and the vaginal opening that allows urine to be expelled from the bladder Vaginal opening—opening between the urethral opening and the perineum; a tubular tract that leads to the uterus Anus—the opening of the digestive tract for the expulsion of feces Tenting effect—the vaginal wall’s increase in size during sexual arousal Mucous membrane—the inner wall of the vagina made up of moist, soft tissue Bartholin’s glands—glands located on each side of the vaginal opening Vaginal lubrication—fluid produced by glands in the vagina to aid in penetration during sexual activity Vagina—an elastic, muscular canal that extends from the vulva inward to the cervix Cervix—the neck of the uterus, connecting the uterus with the vagina Uterus—also called the womb, the structure connected at one end to the cervix and at both sides to the fallopian tubes Orgasm—the peak of sexual excitement, characterized by strong feelings of pleasure and by a series of involuntary contractions of the muscles of the genitals and other areas of the body G-spot orgasm—an orgasm achieved during intercourse that occurs from stimulation to the G-spot rather than the clitoris Fallopian tubes—ducts that connect the ovaries to the uterus Introitus—the opening of the vagina Hymen—the fold of tissue that partially covers the introitus Imperforate hymen—occurs when the tissue of the hymen completely closes the vaginal opening causing menstrual fluid to accumulate Perimetrium—the outer layer of the uterus Myometrium—the middle layer of the uterus which comprises smooth muscle and vascular tissue Endometrium—the inner membrane of the uterus; the lining of which is shed during menstruation Fimbria—the fringe tissue near the ovary leading to the fallopian tube Ovulation—the phase of a woman’s menstrual cycle in which an egg is released Ovary—houses both gonads and endocrine glands; attaches to the fimbria of each fallopian tube to allow release of ovum into the uterus Follicle—part of the ovary; each contains a hollow ball of cells with an immature egg in the center Mammary glands—internal breast; its principal function is to produce milk to nourish an infant after childbirth Areola—the dark visible center of the breast Nipple—the raised bud at the center of the areola Thelarche—the first stage of breast development Estrogen—hormones that produce female reproductive and secondary sex characteristics and impact the functioning of the menstrual cycle Menarche—a female’s first menstrual period Female circumcision—the removal or shortening of the clitoris. It may include sewing the labia together to prevent sexual intercourse or the rupture of the hymen Female genital mutilation (FGM)—performing female circumcision without antiseptic or anesthesia Endocrine system—the system of glands that regulates body functions and processes, including puberty, metabolism, and mood, by releasing hormones Hormone—a chemical substance produced in the body that controls and regulates the activity of certain cells or organs Hypothalamus—the area of the brain that secretes substances that influence pituitary and other gland function and is involved in the control of body temperature, hunger, thirst, and other processes that regulate body equilibrium Pituitary gland—a small oval endocrine gland that lies at the base of the brain. It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation Steroid hormones—a group of hormones that include androgens and estrogens Gonad—glands that make sex hormones and reproductive cells; called testes in the male, ovaries in the female Testosterone—a steroid hormone that helps organize male reproduction and produces secondary sex characteristics in males, and impacts sexual functioning in both sexes Oxytocin—produced in the hypothalamus, is one of the most important neuropeptides Pheromones—chemical signals or odors that bodies release to effect a behavioral or psychological response in another body Menstrual synchrony—alignment of the menstrual cycles of women who live together (such as in homes, prisons, convents, bordellos, dormitories, or barracks) that reportedly occurs over time Menstruation—the shedding of the uterine lining Proliferative phase—the first phase of ovulation Secretory phase—the second phase of ovulation Corpus luteum—the tissue formed from a ruptured ovarian follicle Progesterone—a steroid hormone produced in the ovary; prepares and maintains the uterus for pregnancy Menstrual phase—the third and final phase of ovulation Gonadotropin-releasing hormone (GnRH)—pituitary hormone that stimulates activity in the gonads (testes and ovaries) Luteinizing hormone (LH)—a hormone secreted by the pituitary gland that helps stimulate ovulation in the female. In males it stimulates the production of androgens in the testes Follicle stimulating hormone (FSH)—a hormone secreted by the pituitary gland that helps regulate ovulation in females. In males, it stimulates sperm production Premenstrual syndrome (PMS)—a collection of physical and emotional symptoms that may affect a woman before or during menstruation Neurotransmitters—chemical messengers in the brain Premenstrual dysphoric disorder (PMDD)—a condition in which a woman has severe depression symptoms, irritability, and tension before menstruation. The symptoms of PMDD are more severe than those seen with premenstrual syndrome (PMS) Dysmenorrhea—severe uterine pain during menstruation Amenorrhea—the absence of menstrual periods Toxic shock syndrome (TSS)—a severe disease that produces fever, shock, and problems with the function of several body organs Menopause—the time in a woman’s life when menstruation eventually stops and the body goes through changes that no longer allow her to get pregnant. It is a natural event that normally occurs in women age 45 to 55. Perimenopause—the time when the female body is undergoing changes associated with menopause Hormone replacement therapy (HRT)—treatment that can offset some of the effects of decreased natural levels of hormones associated with menopause Osteoporosis—abnormal bone loss, a potential risk for menopausal women Penis—the primary male organ of sexual pleasure that transports semen as well as urine Root—the base of the penis Erection—the firm and enlarged condition of a body organ or part when the erectile tissue surrounding it becomes filled with blood Penile shaft—the part of the penis between the penile glans and the body Corpus cavernosa—two paired tubular cylinders in the penis that fill with blood during sexual arousal causing an erection Corpus spongiosum—the underlying spongy tissue that surrounds the urethra inside the penis Penile glans—a sexually sensitive area at the very top of the penis that contains numerous nerve endings Corona—the rounded area at the base of the penile glans Foreskin—a thin, sensitive layer of skin that covers part of the shaft, the corona, and the glans of the penis Smegma—smelly, cheesy substance formed by penis secretions that accumulate beneath the foreskin Frenulum—sensitive tissue on the backside of the penis that connects the penile glans with the shaft and the foreskin of the penis Scrotum—an extension of the abdomen located between the penis and the anus Scrotal sac—holds the testicles Testicles—also known as testes or male gonads; are part of the reproductive system that produces sperm and the sex hormone testosterone Cremaster muscle—a muscle in the scrotum that helps to maintain the ideal temperature for sperm production Spermatogenesis—the process of sperm production Seminiferous tubule—a thin, coiled structure in the testes where sperm is produced Tunica albuginea—the capsule that holds the tightly coiled seminiferous tubules Epididymis—a tightly coiled tubular structure that is located on top of each testicle Vas deferens—ducts that help to move sperm from the epididymis to the ejaculatory ducts Penile columns or erectile tissues—spongy tissue within the penis that becomes engorged with blood during an erection Perineum—a sexually sensitive and arousing area in both men and women. In women it extends from the vulva to anus and in men between the scrotum and anus Ejaculation—the ejection of semen (usually carrying sperm) from the male reproductory tract that is usually accompanied by orgasm Seminal vesicles—a pair of tubular glands that produce seminal fluid, which makes up the majority of semen Prostate gland—a gland that produces prostatic secretions Semen—sexual fluid ejaculated through the penis that contains sperm and fluid from the prostate gland, seminal vesicles, and Cowper’s glands Cowper’s gland—during sexual arousal, this structure secretes a clear mucuslike fluid; also called the bulbourethral gland Emission phase—the first of two stages of the ejaculation process Expulsion phase—the second stage of the ejaculation process. Ejaculatory inevitability—during intercourse, the point when semen is about to be secreted and a male feels that he is “about to come” Ejaculatory ducts—two short ducts located within the prostate gland that transport sperm to the urethra prior to ejaculation Detumescence—the soft state of the penis after the semen has been ejaculated Refractory period—the unresponsive time after resolution when a man cannot get a new erection Flaccid—the state of a penis being limp or soft Penile implants—objects or substances inserted into the penis to increase size and pleasure Erectile dysfunction—the inability to gain or sustain an erection Male circumcision—a common genital modification in the United States and other places in which the foreskin is removed from the penis Andropause—a process similar to menopause that occurs in some men Bodily integrity—the idea of the inviolability of the physical body and the importance of personal autonomy and the self-determination of individuals over their own bodies Genital integrity—the idea that someone’s genitals ought to be left intact and not be interfered with by anyone Instructor Manual for Human Sexuality: Self, Society, and Culture Gilbert Herdt, Nicole Polen-Petit 9780073532165, 9780077817527
