Sexual Arousal and Response Chapter 5 This multimedia product and its contents are protected under copyright law. The following are prohibited by law: • any public performance or display, including transmission of any image over a network; • preparation of any derivative work, including the extraction, in whole or in part, of any images; • any rental, lease, or lending of the program. Copyright 2008 Allyn & Bacon Sexual Arousal and Response Making Sense of Sex: The Role of the Senses in Sexual Arousal Aphrodisiacs: Of Spanish Flies and Rhino Horns Sexual Response and the Brain: Cerebral Sex? Sex Hormones: Do They “Goad” Us into Sex? Sexual Response Copyright 2008 Allyn & Bacon Making Sense of Sex All the senses can be responsive to stimuli that enhance or diminish one’s sexual arousal. Vision Visual stimuli are very important to human sexual arousal and response. Smell Odors can be sexually attractive, or off-putting Pheromones: odorless chemicals detected by the nose, that may induce mating behavior Contributes to menstrual synchrony in women Copyright 2008 Allyn & Bacon Making Sense of Sex The Skin Senses Erogenous zones are areas of the body that are especially sensitive to stimulation such as strokes and caresses. Taste Primary erogenous zones have a large number of nerve endings and include the genitals, breasts, and mouth. Secondary erogenous zones are areas of the body that become associated with sexual experiences, perhaps shoulders or backs. Tastes seem to play a minimal role in sexual arousal and response Hearing Auditory stimuli can have a strong influence on sexual arousal and behavior A person’s voice, certain music, certain “dirty” words, etc. Copyright 2008 Allyn & Bacon Aphrodisiacs Aphrodisiacs Substances that cause arousal or increase a person’s capacity for sexual pleasure or response Foods resembling male genitals Drugs that affect the brain’s receptors for dopamine Testosterone Good nutrition and exercise Novelty Copyright 2008 Allyn & Bacon Aphrodisiacs Anaphrodisiacs Substances that inhibit or destroy sexual arousal and response Tranquilizers and barbiturates, which depress the central nervous system Drugs for hypertension Some antidepressants Nicotine Antiandrogen drugs, substances that decrease the level of androgens in the bloodstream Copyright 2008 Allyn & Bacon Aphrodisiacs Psychoactive Drugs Alcohol A small amount can be stimulating, but large amounts often curb sexual arousal & response Reduces sexual inhibitions Binge drinking associated with high-risk sexual behavior Can create feelings of euphoria Copyright 2008 Allyn & Bacon Aphrodisiacs Hallucinogens No proven connection between such drugs and sexual arousal and response. Effects may depend on prior use, attitudes/expectations , and amount Stimulants Activate the central nervous system, but may not have specific sexual effects Can elevate mood, which could increase sexual pleasure Regular users may need the drug to become sexually aroused or may lose the ability to enjoy sex. Copyright 2008 Allyn & Bacon Sexual Response and the Brain Brain Mechanisms in Sexual Functioning The cerebral cortex: the part of the brain that is active when people engage in sexual thoughts, images, wishes, and fantasies. The limbic system: structures active in memory, motivation, and emotion Hypothalamus: Regulates body temperature, drives, hormones, and emotion Copyright 2008 Allyn & Bacon Sexual Response and the Brain INSERT FIGURE 5.1 HERE Copyright 2008 Allyn & Bacon Sexual Response and the Brain Are There Pleasure Centers in the Brain? Electrical stimulation of certain parts of the limbic system has led to reports of sensations similar to sexual gratification. Copyright 2008 Allyn & Bacon Sex Hormones Hormones Substances that are secreted by endocrine glands and regulate various body functions The bodies of both men and women manufacture small amounts of the other gender’s hormones. The testes produce small amounts of estrogen and progesterone. The ovaries produce small amounts of androgens. Copyright 2008 Allyn & Bacon Sex Hormones Sex hormones at puberty result in the development of secondary sex characteristics, which are the physical traits that differentiate males from females but are not directly involved in reproduction. Sex Hormones and Sexual Behavior Sex hormones have organizing influences (they influence the type of behavior expressed) and activating influences (e.g., testosterone influences the motivation to engage in the behavior). Copyright 2008 Allyn & Bacon Sex Hormones Prenatal sex hormones affect sexual differentiation of the genitalia and of the hypothalamus and may explain why some people are transsexual. A person with a gender-identity disorder who feels that he or she is really a member of the other gender and has the body of the wrong gender Copyright 2008 Allyn & Bacon Sex Hormones Sex Hormones and Male Sexual Behavior Male hormones influence sex drive & response Men who are surgically or chemically castrated typically show a gradual decline in sexual desire. Hypogonadism, a condition characterized by abnormally low levels of testosterone production, results in a loss of sexual interest and a reduction in sexual activity. Copyright 2008 Allyn & Bacon Sex Hormones Sex Hormones and Female Sexual Behavior Estrogen and progesterone activate changes that occur during puberty and regulate the menstrual cycle, but do not seem to influence sexual motivation or response in human females. Women who have ovarietomies (surgical removal of the ovaries) continue to be sexually active. Androgens appear to have more of an effect on both men’s and women’s sexual response. Copyright 2008 Allyn & Bacon Sexual Response Sexual Response Cycle Masters and Johnson’s model of sexual response consists of four phases: Excitement phase Plateau phase Orgasmic phase Resolution phase Both women and men experience vasocongestion (swelling of the genital tissues with blood) and myotonia (muscle tension) early in the response cycle. Copyright 2008 Allyn & Bacon Sexual Response Excitement Phase The first phase of the sexual response cycle and is characterized by: Erections in men Vaginal lubrication and genital swelling in women Muscle tension and increases in heart rate in both females and males Sex flush is a reddish rash that may appear on the chest or breasts late in the excitement phase. Copyright 2008 Allyn & Bacon Sexual Response Plateau Phase The second phase of the sexual response cycle and is characterized by: Increases in vasocongestion, muscle tension, heart rate, and blood pressure Orgasmic platform, which is the thickening of the walls of the outer third of the vagina, due to vasocongestion Sex skin, which is the reddening of the labia minora Rapid breathing and heart rate, blood pressure increases Copyright 2008 Allyn & Bacon Sexual Response Orgasmic Phase Male orgasms consist of two stages of muscular contractions. 1st stage: contractions push seminal fluid into urethral bulb 2nd stage: ejaculation Female orgasms involve contractions in the pelvic muscles, uterus, and anal sphincter. In both men and women, muscle spasms occur throughout the body and blood pressure and heart rate peak. Copyright 2008 Allyn & Bacon Sexual Response Resolution Phase The fourth phase of the sexual response cycle, during which the body gradually returns to its prearoused state Refractory period, which men undergo to varying degrees, is a period of time following an orgasm during which an individual is no longer responsive to sexual stimulation. Resolution takes longer when people do not reach orgasm. Blood is released from engorged areas, myotonia dissipates, and blood pressure, heart rate, & respirations return to normal Copyright 2008 Allyn & Bacon Sexual Response Copyright 2008 Allyn & Bacon Sexual Response Kaplan’s Three Stages of Sexual Response: An Alternative Model Desire Excitement Orgasm The stages are independent and their sequence is variable. This model is notable for identifying desire as a separate phase of sexual response. Useful for identifying and treating sexual dysfunctions Copyright 2008 Allyn & Bacon Sexual Response Controversies about Orgasms Multiple Orgasms One or more additional orgasms following the first, which occur within a short period of time and before the body has returned to a preplateau level of arousal Women are more capable of multiple orgasms, by definition, than men are because they do not experience a refractory period. Men may experience multiple orgasms if they are dry orgasms Copyright 2008 Allyn & Bacon Sexual Response Controversies about Orgasms How many kinds of orgasms do women have? Freud: Masters & Johnson Only one type of orgasm Singers Clitoral orgasms Vaginal orgams Vulval orgasm Uterine orgasm Blended orgasm No consensus yet Copyright 2008 Allyn & Bacon