1. Chapter 6 Sexual Arousal and Response

2. The Brain and Sexual Arousal
Cerebral cortex (mental events)
Reasoning, language, and imagination
Limbic system and sexual behavior
Hypothalamus
Neurotransmitters
Dopamine facilitates sexual arousal
Serotonin inhibits sexual arousal

3. The Limbic System and Sexual Behavior
Caption: 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, amygdala, and the hippocampus.

4. The Senses and Sexual Arousal
All sensory systems can contribute to arousal
Touch is the dominant “sexual sense”
Primary erogenous zones
Secondary erogenous zones
Vision usually next in dominance
Visual stimuli
Men self-report higher arousal than women
Women and men have similar physiological responses
It has been said that women enjoy hugging and touching more than genital sex, whereas men have little interest in the “preliminaries,” preferring to “get down to the real thing.” Do you believe this statement reflects a genuine difference between the sexes? If so, is it learned or biologically determined?

5. Other Senses and Sexual Arousal
Smell may arouse or offend
Pheromones
Taste plays a minor role
Hearing plays a variable role

6. Aphrodisiacs
Substances believed to arouse sexual desire or increase capacity for sexual activity
Food
Drugs and alcohol
Yohimbine
No clear evidence of genuine aphrodisiac qualities
Role of expectations
Assume that research eventually reveals that yohimbine or some other substance has genuine aphrodisiac qualities. What possible benefits might be associated with its use? What possible abuses might arise? Would you consider using an aphrodisiac? If so, under what conditions?

7. Anaphrodisiacs Inhibits sexual behavior
Drugs (e.g. opiates, tranquilizers)
Antihypertensives, antidepressants & antipsychotics
Birth control pills
Nicotine
Constricts blood flow
Possibly reduces circulating testosterone

8. 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

9. Sex Hormones in Male Sexual Behavior
Testosterone
Linked to sexual desire and genital sensitivity
Castration leads to reduced sexual desire
Antiandrogen drugs
Hypogonadism

10. Sex Hormones in Female Sexual Behavior
Estrogens
Overall link between estrogen and female sexual behavior is unclear
Estrogen Therapy (ET)
Testosterone
Role as major libido hormone in females

11. How Much Testosterone Is Necessary?
Two forms of testosterone (free and bound)
Free testosterone linked to libido
Although women have less free testosterone, their cells are more sensitive to it than men’s
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

12. Oxytocin and Sexual Behavior
Secreted during cuddling and physical intimacy
Increased skin sensitivity
High levels associated with orgasmic release for women and men
For women, stimulates contractions of uterine wall during orgasm

13. Sexual Response
Caption: 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.

14. Sexual Response Master’s and Johnson’s Four Phases Excitement Plateau
Orgasm
Resolution

15. Sexual Response Master’s and Johnson’s Four Phase Model
Phases of physiological responses
Two basic physiological processes
Vasocongestion
Myotonia

16. Sexual Response Cycle
Caption: Major physiological changes during each of the four phases of the sexual response cycle

17. Female Sexual Response
Caption: Major changes in female sexual anatomy during the sexual response cycle.

18. Male Sexual Response
Caption: Major changes in male sexual anatomy during the sexual response cycle.

19. Orgasm Shortest phase of sexual response cycle
Men and women’s subjective descriptions of orgasm are similar
Most female orgasms result from stimulation of the clitoris
Grafenberg spot
Area on lower front wall of vagina
Sensitive to pressure
Sometimes results in “ejaculation”
Do you believe that men and women differ in the importance they attach to experiencing orgasm during sexual sharing? Why or why not?

20. Sex Differences in Sexual Response
Greater variability in female response
Male refractory period
Women can experience multiple orgasms

21. Locating the Grafenberg Spot
Caption: Locating the Grafenberg spot. Usually two fingers are used, and it is often necessary to press deeply into the anterior wall of the vagina to reach the spot.

22. Aging & 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

23. Aging and the Sexual Response Cycle
Older men
Response cycle continues, with changes in intensity and duration of response
Excitement:
lengthened time to erection
Plateau:
able to sustain plateau phase longer
Orgasm:
reduced muscular contractions and force of ejaculation
Resolution:
occurs more rapidly
refractory period lengthens

24. Age-Related Changes in the Sexual Response Cycle
Caption: Common changes in the sexual response cycle of older women and men.