Sexual Arousal and Response Copyright © 2017 Cengage Learning. All Rights Reserved.

The Brain and Sexual Arousal Key structures Cerebral cortex: higher mental processes Limbic system: various sites linked to sexual behavior Neurotransmitters: dopamine facilitates and serotonin inhibits sexual arousal and activity Classroom Discussion Topic: In what ways does the brain influence sexual arousal? Copyright © 2017 Cengage Learning. All Rights Reserved.

The Limbic System Figure 6.1 The limbic system, a region of the brain associated with emotion and motivation, is important in human sexual function. Key structures, shaded in color, include the cingulate gyrus, portions of the hypothalamus, the amygdala, and the hippocampus. © Cengage Learning Copyright © 2017 Cengage Learning. All Rights Reserved.

The Senses and Sexual Arousal All sensory systems can contribute to arousal Touch tends to predominate Primary erogenous zones Secondary erogenous zones Vision is the second dominate Men self-report higher arousal to visual stimuli Women and men have similar physiological responses Copyright © 2017 Cengage Learning. All Rights Reserved.

The Senses and Sexual Arousal (cont’d.) Smell may arouse or offend Pheromones Taste plays a minor role Partly influenced by industry advertisements Hearing plays a variable role Some find sound arousing Others prefer silence Classroom Discussion Topic: How do the senses of touch, vision, smell, taste, and hearing contribute to erotic arousal? Copyright © 2017 Cengage Learning. All Rights Reserved.

Aphrodisiacs: Do They Work? Substances believed to arouse sexual desire or increase capacity for sexual activity Foods, drugs, and alcohol No clear evidence of genuine aphrodisiac qualities Role of expectations: if a person believes something will improve their sex life, it is often translated into subjective enhancement pleasure Copyright © 2017 Cengage Learning. All Rights Reserved.

Anaphrodisiacs Inhibit sexual behavior Drugs Birth control pills Opiates, tranquilizers, antihypertensives, antidepressants, etc. Birth control pills Reduce blood levels of free testosterone Nicotine Constricts blood flow Possibly reduces circulating testosterone Classroom Discussion Topic: What substances have been shown to either heighten or reduce sexual arousal? Copyright © 2017 Cengage Learning. All Rights Reserved.

The Role of Hormones in Sexual Behavior Steroid hormones Androgens (including testosterone) Produced by testes, adrenal glands, and ovaries Estrogens Produced by ovaries and testes Women and men produce both types Neuropeptide hormones Oxytocin Copyright © 2017 Cengage Learning. All Rights Reserved.

Sex Hormones in Male Sexual Behavior Testosterone Linked to sexual desire and genital sensitivity Castration leads to reduced sexual desire Antiandrogen drugs reduce testosterone Hypogonadism is a testosterone deficiency that results from certain endocrine system diseases Copyright © 2017 Cengage Learning. All Rights Reserved.

Sex Hormones in Female Sexual Behavior Estrogens Overall link between estrogen and female sexual behavior is unclear Estrogen therapy (ET): can lead to sexual benefits (e.g., heightened lubrication and desire) Testosterone Important libido-facilitating hormone in females Copyright © 2017 Cengage Learning. All Rights Reserved.

How Much Testosterone Is Necessary? For normal sexual functioning Too much testosterone is linked to adverse effects Testosterone levels decrease with age Fairly rapid decrease for women at menopause; more gradual decline for men Testosterone replacement therapy: supplements Copyright © 2017 Cengage Learning. All Rights Reserved.

Oxytocin and Sexual Behavior Secreted during cuddling and physical intimacy Increased skin sensitivity Associated with orgasmic release Facilitates emotional and erotic bonding Linked to social attachment Classroom Discussion Topic: What is the role of hormones in human sexual arousal? Copyright © 2017 Cengage Learning. All Rights Reserved.

Sexual Response Kaplan’s three-stage model Desire, excitement, and orgasm Masters and Johnson’s four-phase model Excitement, plateau, orgasm, and resolution Classroom Discussion Topic: What common physiological changes accompany each stage of the sexual response cycles? Copyright © 2017 Cengage Learning. All Rights Reserved.

Kaplan’s Three-Stage Model Figure 6.2 Kaplan’s three-stage model of the sexual response cycle. This model is distinguished by its identification of desire as a prelude to sexual response. Source: Kaplan 1979. Copyright © 2017 Cengage Learning. All Rights Reserved.

Female Sexual Response Cycle Figure 6.3 Female sexual response cycle. Masters and Johnson identified three basic patterns in female sexual response. Pattern A most closely resembles the male pattern, except that a woman can have one or more orgasms without dropping below the plateau level of sexual arousal. Variations of this response include an extended plateau with no orgasm (pattern B) and a rapid rise to orgasm with no definitive plateau and a quick resolution (pattern C). Source: Human Sexual Response, by W.H. Masters and V.E. Johnson. Copyright © 1966 Copyright © 2017 Cengage Learning. All Rights Reserved.

Male Sexual Response Cycle Figure 6.4 Male sexual response cycle. Only one male response pattern was identified by Masters and Johnson. However, men do report considerable variation in their response pattern. Note the refractory period; males do not have a second orgasm immediately after the first. Source: Human Sexual Response, by W.H. Masters and V.E. Johnson. Copyright © 1966 Copyright © 2017 Cengage Learning. All Rights Reserved.

Four Phases of the Sexual Response Cycle Table 6.3 Major Physiological Changes During Each of the Four Phases of the Sexual Response Cycle Copyright © 2017 Cengage Learning. All Rights Reserved.

Aging and the Sexual Response Cycle Older women: response cycle continues but with decreased intensity Excitement: vaginal lubrication begins more slowly, reduced amount Plateau: decreased vagina flexibility Orgasm: number of uterine contractions decrease Resolution: occurs more rapidly Copyright © 2017 Cengage Learning. All Rights Reserved.

Aging and the Sexual Response Cycle (cont’d.) Older men: response cycle continues, but with changes in intensity and duration of response Excitement: more stimulation to obtain erection Plateau: able to sustain plateau phase longer Orgasm: reduced muscular contractions and force of ejaculation Resolution: occurs more rapidly and refractory period lengthens Classroom Discussion Topic: What common variations occur in the sexual response cycles of older women and men? Copyright © 2017 Cengage Learning. All Rights Reserved.

Differences Between the Sexes in Sexual Response Greater variability in female response See Figure 6.3 Male refractory period Certain minimum time must elapse after orgasm before another climax Multiple orgasms More than one orgasm within a short time period Most women have the capacity for multiple orgasms What are some of the significant differences between the sexes in response patterns? Copyright © 2017 Cengage Learning. All Rights Reserved.

Summary Sexual arousal and sexual response in humans are influenced by many factors Brain’s capacity to create images and fantasies Our emotions and the level of intimacy Various sensory processes and hormones Biological factors and events Differences between the sexes Copyright © 2017 Cengage Learning. All Rights Reserved.