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81-600: Sexology is the scientific study of human sexuality , including human sexual interests, behaviors , and functions. The term sexology does not generally refer to the non-scientific study of sexuality, such as social criticism . Sexologists apply tools from several academic fields, such as anthropology , biology , medicine , psychology , epidemiology , sociology , and criminology . Topics of study include sexual development (puberty), sexual orientation , gender identity , sexual relationships , sexual activities, paraphilias , and atypical sexual interests. It also includes
162-437: A depository for sperm. The vagina is also the birth canal ; it can expand to 10 cm (3.9 in) during labor and delivery. The vagina is located between the bladder and the rectum . The vagina is normally collapsed, but during sexual arousal it opens, lengthens, and produces lubrication to allow the insertion of the penis. The vagina has three layered walls; it is a self-cleaning organ with natural bacteria that suppress
243-409: A disease, immoral, or a crime. The work assumes that same-sex love transcended age taboos as well as gender taboos. Seven of his twenty-one case studies are of inter-generational relationships. He also developed other important psychological concepts, such as autoerotism and narcissism , both of which were later developed further by Sigmund Freud . Ellis pioneered transgender phenomena alongside
324-463: A fertilized egg (ovum) will implant itself and grow into a fetus. The uterus lies in the pelvic cavity between the bladder and the bowel , and above the vagina. It is usually positioned in a 90-degree angle tilting forward, although in about 20% of women it tilts backwards. The uterus has three layers; the innermost layer is the endometrium , where the egg is implanted. During ovulation, this thickens for implantation. If implantation does not occur, it
405-503: A higher number of sexual partners) than women. These theories are mostly consistent with observed differences in males' and females' attitudes toward casual sex before marriage in the United States. Other aspects of human sexuality, such as sexual satisfaction, incidence of oral sex , and attitudes toward homosexuality and masturbation , show little to no observed difference between males and females. Observed gender differences regarding
486-552: A means to an end, to increase emotional connection, and to alleviate insecurity. Until Sigmund Freud published his Three Essays on the Theory of Sexuality in 1905, children were often regarded as asexual , having no sexuality until later development. Sigmund Freud was one of the first researchers to take child sexuality seriously. His ideas, such as psychosexual development and the Oedipus conflict , have been much debated but acknowledging
567-444: A monthly basis. Once matured, these are called Graafian follicles . The female reproductive system does not produce the ova; about 60,000 ova are present at birth, only 400 of which will mature during the woman's lifetime. Ovulation is based on a monthly cycle; the 14th day is the most fertile. On days one to four, menstruation and production of estrogen and progesterone decreases, and the endometrium starts thinning. The endometrium
648-399: A person's sense of their own gender , whether male, female, or non-binary . Gender identity can correlate with assigned sex at birth or can differ from it. All societies have a set of gender categories that can serve as the basis of the formation of a person's social identity in relation to other members of society. Sexual behavior and intimate relationships are strongly influenced by
729-520: A person's sexual orientation. Sexual orientation is an enduring pattern of romantic or sexual attraction (or a combination of these) to persons of the opposite sex, same sex, or both sexes. Heterosexual people are romantically/sexually attracted to the members of the opposite sex, gay and lesbian people are romantically/sexually attracted to people of the same sex, and those who are bisexual are romantically/sexually attracted to both sexes. The idea that homosexuality results from reversed gender roles
810-607: A pinkish appearance. Near the anus, the labia minora merge with the labia majora. In a sexually unstimulated state, the labia minora protects the vaginal and urethral opening by covering them. At the base of the labia minora are the Bartholin's glands , which add a few drops of an alkaline fluid to the vagina via ducts; this fluid helps to counteract the acidity of the outer vagina since sperm cannot live in an acidic environment. The Skene's glands are possibly responsible for secreting fluid during female ejaculation . The clitoris
891-752: Is a female sexual dysfunction leading to a lack of vaginal lubrication. In addition, blood flow problems may affect arousal disorder. Lack of orgasm, also known as anorgasmia, is another sexual dysfunction in women. The last sexual disorder is painful intercourse, which can be caused by factors including pelvic mass, scar tissue, and sexually transmitted infections. Three common sexual disorders for men are sexual desire disorder, ejaculation disorder, and erectile dysfunction. Lack of sexual desire in men may be caused by physical issues like low testosterone or psychological factors such as anxiety and depression. Ejaculation disorders include retrograde ejaculation, retarded ejaculation, and premature ejaculation. Erectile dysfunction
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#1732858314233972-456: Is a regulated profession in some jurisdictions. In Quebec, sexologists must be members of the Ordre professionnel des sexologues du Québec. They are one of the professions eligible to receive psychotherapy permits from the Ordre des psychologues du Québec. This is a list of sexologists and notable contributors to the field of sexology, by year of birth: Human sexuality Human sexuality
1053-442: Is a small area at the base of the brain consisting of several groups of nerve cell bodies that receive input from the limbic system . Studies have shown that within lab animals, the destruction of certain areas of the hypothalamus causes the elimination of sexual behavior. The hypothalamus is important because of its relationship to the pituitary gland , which lies beneath it. The pituitary gland secretes hormones that are produced in
1134-533: Is affected by cultural, political, legal, philosophical, moral , ethical , and religious aspects of life. Interest in sexual activity normally increases when an individual reaches puberty . Although no single theory on the cause of sexual orientation has yet gained widespread support, there is considerably more evidence supporting nonsocial causes of sexual orientation than social ones, especially for males. Hypothesized social causes are supported by only weak evidence, distorted by numerous confounding factors. This
1215-400: Is also cyclic, but unlike the female ovulation cycle, the sperm production cycle is constantly producing millions of sperm daily. The external male genitalia are the penis and the scrotum . The penis provides a passageway for sperm and urine. The penis consists of nerves, blood vessels, fibrous tissue, and three parallel cylinders of spongy tissue. Other components of the penis include
1296-532: Is also released in women when they give birth or are breastfeeding. Prolactin and oxytocin are responsible for inducing milk production in women. Follicle-stimulating hormone (FSH) is responsible for ovulation in women, and acts by triggering egg maturity; in men, it stimulates sperm production. Luteinizing hormone (LH) triggers ovulation, which is the release of a mature egg. Males have both internal and external genitalia that are responsible for procreation and sexual intercourse. Production of spermatozoa ( sperm )
1377-401: Is an inability to initiate and maintain an erection during intercourse. As one form of behavior, the psychological aspects of sexual expression have been studied in the context of emotional involvement, gender identity, intersubjective intimacy, and Darwinian reproductive efficacy. Sexuality in humans generates profound emotional and psychological responses. Some theorists identify sexuality as
1458-836: Is considerably more evidence supporting innate causes of sexual orientation than learned ones, especially for males. This evidence includes the cross-cultural correlation of homosexuality and childhood gender nonconformity , moderate genetic influences found in twin studies , evidence for prenatal hormonal effects on brain organization, the fraternal birth order effect , and the finding that in rare cases where infant males were raised as girls due to physical differences or deformity, they nevertheless turned out attracted to females. Hypothesized social causes are supported by only weak evidence, distorted by numerous confounding factors. Cross-cultural evidence also leans more toward non-social causes. Cultures that are very tolerant of homosexuality do not have significantly higher rates of it. Homosexual behavior
1539-477: Is developed from the same embryonic tissue as the penis; it or its glans alone consists of as many (or more in some cases) nerve endings as the human penis or glans penis, making it extremely sensitive to touch. The clitoral glans, which is a small, elongated erectile structure, has only one known function—sexual sensations. It is the female's most sensitive erogenous zone and the main source of orgasm in women. Thick secretions called smegma collect around
1620-613: Is further supported by cross-cultural evidence because cultures that are tolerant of homosexuality do not have significantly higher rates of it. Evolutionary perspectives on human coupling, reproduction and reproduction strategies , and social learning theory provide further views of sexuality. Sociocultural aspects of sexuality include historical developments and religious beliefs . Some cultures have been described as sexually repressive . The study of sexuality also includes human identity within social groups, sexually transmitted infections (STIs), and birth control methods. There
1701-774: Is not fully understood why genes causing homosexuality persist in the gene pool. One hypothesis involves kin selection , suggesting that homosexuals invest heavily enough in their relatives to offset the cost of not reproducing as much directly. This has not been supported by studies in Western cultures, but several studies in Samoa have found some support for this hypothesis. Another hypothesis involves sexually antagonistic genes, which cause homosexuality when expressed in males but increase reproduction when expressed in females. Studies in both Western and non-Western cultures have found support for this hypothesis. Psychological theories exist regarding
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#17328583142331782-434: Is reinforced by the media's portrayal of gay men as feminine and lesbians as masculine. However, a person's conformity or non-conformity to gender stereotypes does not always predict sexual orientation. Society believes that if a man is masculine, he is heterosexual, and if a man is feminine, he is homosexual. There is no strong evidence that a homosexual or bisexual orientation must be associated with atypical gender roles. By
1863-502: Is relatively common among boys in British single-sex boarding schools, but adult Britons who attended such schools are no more likely to engage in homosexual behavior than those who did not. In an extreme case, the Sambia people ritually require their boys to engage in homosexual behavior during adolescence before they have any access to females, yet most of these boys become heterosexual. It
1944-439: Is sloughed off during menstruation. The cervix is the narrow end of the uterus. The broad part of the uterus is the fundus . During ovulation , the ovum travels down the fallopian tubes to the uterus. These extend about four inches (10 cm) from both sides of the uterus. Finger-like projections at the ends of the tubes brush the ovaries and receive the ovum once it is released. The ovum then travels for three to four days to
2025-412: Is sloughed off for the next three to six days. Once menstruation ends, the cycle begins again with an FSH surge from the pituitary gland. Days five to thirteen are known as the pre-ovulatory stage. During this stage, the pituitary gland secretes follicle-stimulating hormone (FSH). A negative feedback loop is enacted when estrogen is secreted to inhibit the release of FSH. Estrogen thickens the endometrium of
2106-412: Is the ejaculatory ducts, which are 1-inch (2.5 cm)-long paired tubes that pass through the prostate gland, where semen is produced. The prostate gland is a solid, chestnut-shaped organ that surrounds the first part of the urethra, which carries urine and semen. Similar to the female G-spot, the prostate provides sexual stimulation and can lead to orgasm through anal sex . The prostate gland and
2187-412: Is the release of tension, and the resolution period is the unaroused state before the cycle begins again. The male sexual response cycle starts in the excitement phase; two centers in the spine are responsible for erections. Vasoconstriction in the penis begins, the heart rate increases, the scrotum thickens, the spermatic cord shortens, and the testicles become engorged with blood. In the plateau phase,
2268-420: Is the way people experience and express themselves sexually . This involves biological , psychological , physical , erotic , emotional , social , or spiritual feelings and behaviors. Because it is a broad term, which has varied with historical contexts over time, it lacks a precise definition. The biological and physical aspects of sexuality largely concern the human reproductive functions , including
2349-531: Is to provide milk to a developing infant. Breasts develop during puberty in response to an increase in estrogen. Each adult breast consists of 15 to 20 milk-producing mammary glands , irregularly shaped lobes that include alveolar glands and a lactiferous duct leading to the nipple. The lobes are separated by dense connective tissues that support the glands and attach them to the tissues on the underlying pectoral muscles. Other connective tissue, which forms dense strands called suspensory ligaments, extends inward from
2430-686: The Kama Sutra of Vatsyayana , the Ananga Ranga , and The Perfumed Garden for the Soul's Recreation . De la prostitution dans la ville de Paris ( Prostitution in the City of Paris ), an early 1830s study on 3,558 registered prostitutes in Paris , written by Alexander Jean Baptiste Parent-Duchatelet (published in 1837, a year after he died), has been called the first work of modern sex research. In England, James Graham
2511-460: The G-spot is named, published the initial research developing the intrauterine device (IUD). After World War II, sexology experienced a renaissance, both in the United States and Europe. Large scale studies of sexual behavior, sexual function, and sexual dysfunction gave rise to the development of sex therapy . Post-WWII sexology in the U.S. was influenced by the influx of European refugees escaping
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2592-549: The Masters & Johnson Institute in 1978. Vern Bullough was a historian of sexology during this era, as well as being a researcher in the field. The emergence of HIV/AIDS in the 1980s caused a dramatic shift in sexological research efforts towards understanding and controlling the spread of the disease. Technological advances have permitted sexological questions to be addressed with studies using behavioral genetics, neuroimaging, and large-scale Internet-based surveys. Sexology
2673-417: The corpus luteum —secretes estrogen. Production of progesterone increases, inhibiting LH release. The endometrium thickens to prepare for implantation, and the ovum travels down the fallopian tubes to the uterus. If the ovum is not fertilized and does not implant, menstruation begins. The sexual response cycle is a model that describes the physiological responses that occur during sexual activity. This model
2754-424: The development of the reproductive system . As adults, they have different reproductive mechanisms that enable them to perform sexual acts and to reproduce. Men and women react similarly to sexual stimuli with minor differences. Women have a monthly reproductive cycle, whereas the male sperm production cycle is more continuous. The hypothalamus is the most important part of the brain for sexual functioning. This
2835-496: The human sexual response cycle . Someone's sexual orientation is their pattern of sexual interest in the opposite and/or same sex. Physical and emotional aspects of sexuality include bonds between individuals that are expressed through profound feelings or physical manifestations of love , trust, and care. Social aspects deal with the effects of human society on one's sexuality, while spirituality concerns an individual's spiritual connection with others. Sexuality also affects and
2916-565: The labia or "lips". The labia majora are two elongated folds of skin extending from the mons to the perineum . Its outer surface becomes covered with hair after puberty. In between the labia majora are the labia minora, two hairless folds of skin that meet above the clitoris to form the clitoral hood , which is highly sensitive to touch. The labia minora become engorged with blood during sexual stimulation, causing them to swell and turn red. The labia minora are composed of connective tissues that are richly supplied with blood vessels which cause
2997-536: The penile plethysmograph in Czechoslovakia in the 1950s. The device was designed to provide an objective measurement of sexual arousal in males and is currently used in the assessment of pedophilia and hebephilia . This tool has since been used with sex offenders . In 1966 and 1970, Masters and Johnson released their works Human Sexual Response and Human Sexual Inadequacy, respectively. Those volumes sold well, and they were founders of what became known as
3078-410: The seminiferous tubules , coiled tubes at the top and back of each testicle. The second part of the duct system is the vas deferens , a muscular tube that begins at the lower end of the epididymis. The vas deferens passes upward along the side of the testicles to become part of the spermatic cord. The expanded end is the ampulla, which stores sperm before ejaculation. The third part of the duct system
3159-424: The shaft , glans , root, cavernous bodies , and spongy body . The three cylindrical bodies of spongy tissue, which are filled with blood vessels, run along the length of the shaft. The two bodies that lie side by side in the upper portion of the penis are the corpora cavernosa (cavernous bodies). The third, called the corpus spongiosum (spongy body), is a tube that lies centrally beneath the others and expands at
3240-524: The testicles , the duct system, the prostate and seminal vesicles , and the Cowper's gland . The testicles (male gonads), are where sperm and male hormones are produced. Millions of sperm are produced daily in several hundred seminiferous tubules. Cells called the Leydig cells lie between the tubules; these produce hormones called androgens; these consist of testosterone and inhibin . The testicles are held by
3321-494: The German Magnus Hirschfeld . He established it as new category that was separate and distinct from homosexuality. Aware of Hirschfeld's studies of transvestism , but disagreeing with his terminology, in 1913 Ellis proposed the term sexo-aesthetic inversion to describe the phenomenon. In 1908, the first scholarly journal of the field, Journal of Sexology ( Zeitschrift für Sexualwissenschaft ), began publication and
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3402-696: The Nazi regime and the popularity of the Kinsey studies . Until that time, American sexology consisted primarily of groups working to end prostitution and to educate youth about sexually transmitted infections . Alfred Kinsey founded the Institute for Sex Research at Indiana University at Bloomington in 1947. This is now called the Kinsey Institute for Research in Sex, Gender and Reproduction. He wrote in his 1948 book that more
3483-513: The bladder with the urethra; it expels urine from the bladder. This is located below the clitoris and above the vaginal opening. The breasts are the subcutaneous tissues on the front thorax of the female body. Though they are not technically part of a woman's sexual anatomy, they do have roles in both sexual pleasure and reproduction. Breasts are modified sweat glands made up of fibrous tissues and fat that provide support and contain nerves, blood vessels, and lymphatic vessels. Their main purpose
3564-590: The categories of homosexuality, he referred to these people as transvestiten (transvestites). Germany's dominance in sexual behavior research ended with the Nazi regime . The Institute and its library were destroyed by the Nazis less than three months after they took power, May 8, 1933. The institute was shut down and Hirschfeld's books were burned. Other sexologists in the early gay rights movement included Ernst Burchard and Benedict Friedlaender . Ernst Gräfenberg , after whom
3645-399: The central source of human personality. Psychological studies of sexuality focus on psychological influences that affect sexual behavior and experiences. Early psychological analyses were carried out by Sigmund Freud , who believed in a psychoanalytic approach. He also proposed the concepts of psychosexual development and the Oedipus complex , among other theories. Gender identity is
3726-418: The chest and back; breasts increase slightly in size and nipples may become hardened and erect. The onset of vasocongestion results in swelling of the clitoris, labia minora, and vagina. The muscle that surrounds the vaginal opening tightens and the uterus elevates and grows in size. The vaginal walls begin to produce a lubricating liquid. The second phase, called the plateau phase, is characterized primarily by
3807-399: The clitoris, vagina, and cervix). This may be why many women find nipple stimulation arousing and why some women are able to orgasm by nipple stimulation alone. The female internal reproductive organs are the vagina , uterus , fallopian tubes , and ovaries . The vagina is a sheath-like canal that extends from the vulva to the cervix. It receives the penis during intercourse and serves as
3888-400: The clitoris. The vaginal opening and the urethral opening are only visible when the labia minora are parted. These openings have many nerve endings that make them sensitive to touch. They are surrounded by a ring of sphincter muscles called the bulbocavernosus muscle . Underneath this muscle and on opposite sides of the vaginal opening are the vestibular bulbs, which help the vagina grip
3969-408: The development and expression of gender differences in human sexuality. A number of them (including neo-analytic theories, sociobiological theories, social learning theory, social role theory , and script theory ) agree in predicting that men should be more approving of casual sex (sex happening outside a stable, committed relationship such as marriage ) and should also be more promiscuous (have
4050-456: The early 21st century, homosexuality was no longer considered to be a pathology. Theories have linked many factors, including genetic, anatomical, birth order, and hormones in the prenatal environment, to homosexuality. Other than the need to procreate, there are many other reasons people have sex. According to one study conducted on college students (Meston & Buss, 2007), the four main reasons for sexual activities are physical attraction, as
4131-451: The end to form the tip of the penis (glans). During arousal , these bodies erect the penis by filling with blood. The raised rim at the border of the shaft and glans is called the corona. The urethra connects the urinary bladder to the penis where urine exits the penis through the urethral meatus . The urethra eliminates urine and acts as a channel for semen and sperm to exit the body during sexual intercourse. The root consists of
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#17328583142334212-495: The existence of child sexuality was an important development. Freud gave sexual drives an importance and centrality in human life, actions, and behavior; he said sexual drives exist and can be discerned in children from birth. He explains this in his theory of infantile sexuality , and says sexual energy ( libido ) is the most important motivating force in adult life. Freud wrote about the importance of interpersonal relationships to one's sexual and emotional development. From birth,
4293-484: The expanded ends of the cavernous bodies, which fan out to form the crura and attach to the pubic bone and the expanded end of the spongy body. The bulb of the penis is surrounded by the bulbospongiosus muscle , while the corpora cavernosa are surrounded by the ischiocavernosus muscles . These aid urination and ejaculation . The penis has a foreskin that typically covers the glans; this is sometimes removed by circumcision for medical, religious or cultural reasons. In
4374-514: The expulsion phase; it cannot be reached without an orgasm. In the resolution phase, the male is now in an unaroused state consisting of a refractory (rest) period before the cycle can begin. This rest period may increase with age. The female sexual response begins with the excitement phase, which can last from several minutes to several hours. Characteristics of this phase include increased heart and respiratory rate, and an elevation of blood pressure. Flushed skin or blotches of redness may occur on
4455-421: The hypothalamus and itself. The four important sexual hormones are oxytocin , prolactin , follicle-stimulating hormone , and luteinizing hormone . Oxytocin, sometimes referred to as the "love hormone", is released in both sexes during sexual intercourse when an orgasm is achieved. Oxytocin has been suggested as critical to the thoughts and behaviors required to maintain close relationships. The hormone
4536-461: The institute to gain a clearer understanding of their sexuality and to be treated for their sexual concerns and dysfunctions. Hirschfeld developed a system which identified numerous actual or hypothetical types of sexual intermediary between heterosexual male and female to represent the potential diversity of human sexuality, and is credited with identifying a group of people that today are referred to as transsexual or transgender as separate from
4617-421: The intensification of the changes begun during the excitement phase. The plateau phase extends to the brink of orgasm, which initiates the resolution stage; the reversal of the changes begun during the excitement phase. During the orgasm stage the heart rate, blood pressure, muscle tension, and breathing rates peak. The pelvic muscle near the vagina, the anal sphincter, and the uterus contract. Muscle contractions in
4698-504: The late 19th and early 20th centuries. Wilhelm Reich and Otto Gross were disciples of Freud, but rejected his theories because of their emphasis on the role of sexuality in the revolutionary struggle for the emancipation of mankind. Pre-Nazi Germany, under the sexually liberal Napoleonic code , organized and resisted the anti-sexual, Victorian cultural influences. The momentum from those groups led them to coordinate sex research across traditional academic disciplines , bringing Germany to
4779-590: The leadership of sexology. Physician Magnus Hirschfeld was an outspoken advocate for sexual minorities, founding the Scientific Humanitarian Committee , the first advocacy for homosexual and transgender rights. Hirschfeld also set up the first Institut für Sexualwissenschaft (Institute for Sexology) in Berlin in 1919. Its library housed over 20,000 volumes, 35,000 photographs, a large collection of art and other objects. People from around Europe visited
4860-463: The mother's connection to the infant affects the infant's later capacity for pleasure and attachment . Freud described two currents of emotional life; an affectionate current, including our bonds with the important people in our lives; and a sensual current, including our wish to gratify sexual impulses. During adolescence, a young person tries to integrate these two emotional currents. Autoerotism Too Many Requests If you report this error to
4941-617: The number of sexual partners are modest, with males tending to have slightly more than females. Like other mammals , humans are primarily grouped into either the male or female sex. The biological aspects of human sexuality deal with the reproductive system, the sexual response cycle, and the factors that affect these aspects. They also deal with the influence of biological factors on other aspects of sexuality, such as organic and neurological responses, heredity, hormonal issues, gender issues, and sexual dysfunction. Males and females are anatomically similar; this extends to some degree to
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#17328583142335022-444: The penis by swelling with blood during arousal. Within the vaginal opening is the hymen , a thin membrane that partially covers the opening in many virgins . Rupture of the hymen has been historically considered the loss of one's virginity, though, by modern standards, loss of virginity is considered to be the first sexual intercourse. The hymen can be ruptured by activities other than sexual intercourse. The urethral opening connects to
5103-448: The penis increases in diameter, the testicles become more engorged, and the Cowper's glands secrete pre-seminal fluid. The orgasm phase, during which rhythmic contractions occur every 0.8 seconds, consists of two phases; the emission phase, in which contractions of the vas deferens, prostate, and seminal vesicles encourage ejaculation, which is the second phase of orgasm. Ejaculation is called
5184-501: The prevailing social attitude of sexual repression in the Victorian era , the movement towards sexual emancipation began towards the end of the nineteenth century in England and Germany. In 1886, Richard Freiherr von Krafft-Ebing published Psychopathia Sexualis . That work is considered as having established sexology as a scientific discipline. In England, the founding father of sexology
5265-474: The production of yeast. The G-spot , named after the Ernst Gräfenberg who first reported it in 1950, may be located in the front wall of the vagina and may cause orgasms. This area may vary in size and location between women; in some it may be absent. Various researchers dispute its structure or existence or regard it as an extension of the clitoris. The uterus or womb is a hollow, muscular organ where
5346-416: The same embryonic tissue as the testicles . The ovaries are suspended by ligaments and are the source where ova are stored and developed before ovulation. The ovaries also produce female hormones progesterone and estrogen . Within the ovaries, each ovum is surrounded by other cells and contained within a capsule called a primary follicle. At puberty, one or more of these follicles are stimulated to mature on
5427-400: The scrotum, the testicles are held away from the body, one possible reason for this is so sperm can be produced in an environment slightly lower than normal body temperature. The penis has very little muscular tissue, and this exists in its root. The shaft and glans have no muscle fibers. Unlike most other primates, male humans lack a penile bone . Male internal reproductive structures are
5508-505: The seminal vesicles produce seminal fluid that is mixed with sperm to create semen. The prostate gland lies under the bladder and in front of the rectum. It consists of two main zones: the inner zone that produces secretions to keep the lining of the male urethra moist and the outer zone that produces seminal fluids to facilitate the passage of semen. The seminal vesicles secrete fructose for sperm activation and mobilization, prostaglandins to cause uterine contractions that aid movement through
5589-424: The skin of the breast to the pectoral tissue to support the weight of the breast. Heredity and the quantity of fatty tissue determine the size of the breasts. Men typically find female breasts attractive and this holds true for a variety of cultures. In women, stimulation of the nipple seems to result in activation of the brain's genital sensory cortex (the same region of the brain activated by stimulation of
5670-408: The spermatic cord, which is a tubelike structure containing blood vessels, nerves, the vas deferens, and a muscle that helps to raise and lower the testicles in response to temperature changes and sexual arousal, in which the testicles are drawn closer to the body. Sperm gets transported through a four-part duct system. The first part of this system is the epididymis . The testicles converge to form
5751-439: The study of sexuality across the lifespan, including child sexuality , puberty , adolescent sexuality , and sexuality among the elderly . Sexology also spans sexuality among those with mental or physical disabilities. The sexological study of sexual dysfunctions and disorders, including erectile dysfunction and anorgasmia , are also mainstays. Sex manuals have existed since antiquity, such as Ovid 's Ars Amatoria ,
5832-465: The uterus, and bases that help neutralize the acidity of the vagina. The Cowper's glands, or bulbourethral glands, are two pea-sized structures beneath the prostate. The external female genitalia are the vulva . The mons pubis is a soft layer of fatty tissue overlaying the pubic bone. Following puberty, this area grows in size. It has many nerve endings and is sensitive to stimulation. The labia minora and labia majora are collectively known as
5913-468: The uterus. After sexual intercourse, sperm swim up this funnel from the uterus. The lining of the tube and its secretions sustain the egg and the sperm, encouraging fertilization and nourishing the ovum until it reaches the uterus. If the ovum divides after fertilization, identical twins are produced. If separate eggs are fertilized by different sperm, the mother gives birth to non-identical or fraternal twins . The ovaries (female gonads), develop from
5994-509: The uterus. A surge of luteinizing hormone (LH) triggers ovulation. On day 14, the LH surge causes a Graafian follicle to surface the ovary. The follicle ruptures and the ripe ovum is expelled into the abdominal cavity. The fallopian tubes pick up the ovum with the fimbria . The cervical mucus changes to aid the movement of sperm. On days 15 to 28—the post-ovulatory stage, the Graafian follicle—now called
6075-943: The vaginal area create a high level of pleasure, though all orgasms are centered in the clitoris. Sexual disorders, according to the DSM-IV-TR, are disturbances in sexual desire and psycho-physiological changes that characterize the sexual response cycle and cause marked distress and interpersonal difficulty. Sexual dysfunctions are a result of physical or psychological disorders. Physical causes include hormonal imbalance, diabetes, heart disease and more; psychological causes include but are not limited to stress, anxiety, and depression. Sexual dysfunction affects both men and women. There are four major categories of sexual problems in women: desire disorders, arousal disorders, orgasmic disorders, and sexual pain disorders. Sexual desire disorder occurs when an individual lacks sexual desire because of hormonal changes, depression, and pregnancy. Arousal disorder
6156-419: Was an early sexologist who lectured on topics such as the process of sex and conception. The scientific study of sexual behavior in human beings began in the 19th century with Heinrich Kaan , whose book Psychopathia Sexualis (1844) Michel Foucault describes as marking "the date of birth, or in any case the date of the emergence of sexuality and sexual aberrations in the psychiatric field." The term sexology
6237-448: Was coined for the first time in the United States by Elizabeth Osgood Goodrich Willard in 1867. Roughly simultaneously a group of homophile activists, not yet identifying themselves as sexologists, were responding to shifts in Europe 's national borders, a crisis that brought into conflict laws that were sexually liberal and laws that criminalized behaviors such as homosexual activity. Despite
6318-492: Was created by William Masters and Virginia Johnson . According to Masters and Johnson, the human sexual response cycle consists of four phases; excitement, plateau, orgasm, and resolution, also called the EPOR model. During the excitement phase of the EPOR model, one attains the intrinsic motivation to have sex. The plateau phase is the precursor to orgasm, which may be mostly biological for men and mostly psychological for women. Orgasm
6399-476: Was published monthly for one year. Those issues contained articles by Freud, Alfred Adler , and Wilhelm Stekel . In 1913, the first academic association was founded: the Society for Sexology . Freud developed a theory of sexuality. These stages of development include: Oral , Anal , Phallic , Latency and Genital . These stages run from infancy to puberty and onwards. based on his studies of his clients, between
6480-473: Was scientifically known about the sexual behavior of farm animals than of humans. Psychologist and sexologist John Money developed theories on sexual identity and gender identity in the 1950s. His work, notably on the David Reimer case has since been regarded as controversial, even while the case was key to the development of treatment protocols for intersex infants and children. Kurt Freund developed
6561-460: Was the doctor and sexologist Havelock Ellis who challenged the sexual taboos of his era regarding masturbation and homosexuality and revolutionized the conception of sex in his time. His seminal work was the 1897 Sexual Inversion , which describes the sexual relations of homosexual males, including men with boys. Ellis wrote the first objective study of homosexuality (the term was coined by Karl-Maria Kertbeny ), as he did not characterize it as
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