1. Chapter 6 Sexual Arousal and Response

2. Sexual Arousal The role of hormones Steroid hormones
testosterone: male sex hormones
produced by testes, adrenal glands, & ovaries
estrogen: female sex hormone
produced by ovaries & testes
Neuropeptide hormones
oxytocin

3. Sexual Arousal (cont.) Hormones in male sexual behavior
testosterone and desire
castration research
androgen-blocking drugs
hypogonadism
hormones in female sexual behavior
estrogen and ERT
positive correlation between testosterone & frequency of activity

4. Sexual Arousal (cont.) The role of hormones
how much testosterone is necessary?
two forms of testosterone
testosterone and libido
"critical mass" varies
excessive testosterone can harm both sexes over time
testosterone replacement therapy
oxytocin and sexual response

5. Sexual Arousal (cont.)
Table 6.1 Common signs of testosterone deficiency.

6. Sexual Arousal (cont.) The brain cerebral cortex (mental events)
limbic system affects feeling & behavior
cingulate gyrus
amygdala
hypocampus
hypothalamus
neurotransmitters

7. Sexual Arousal (cont.)
Fig. 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, amygdala, and the hippocampus.

8. Sexual Arousal (cont.) The senses touch is the dominant "sexual sense"
primary erogenous zones
secondary erogenous zones
vision is usually next in dominance
self-report: males more than females
equal physiological signs of arousal

9. Sexual Arousal (cont.) The senses smell may arouse or offend
exposure to a human pheromone increases attractiveness ratings
taste plays a minor role
hearing plays a variable role

10. Sexual Arousal (cont.) Aphrodisiacs food alcohol and other drugs
yohimbine
role of expectations

11. Sexual Arousal (cont.) anaphrodisiacs
drugs: e.g.,opiates, tranquilizers
antidepressants and antipsychotics
birth control pills
nicotine constricts blood vessels, slows vasocongestive response; reduces circulating testosterone

12. Sexual Response Kaplan's three-stage model
desire: distinct, but not required
excitement
orgasm

13. Sexual Response (cont.)
Fig. 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.

14. Sexual Response (cont.)
Masters & Johnson's four phases
Physiological sources of arousal
Problems:
simplified
too literal interpretation of plateau stage
not to be used as a personal standard

15. Sexual Response (cont.)
Two basic processes
Vasocongestion
Myotonia

16. Sexual Response (cont.)
Masters & Johnson's four phases
Excitement
Plateau
Orgasm
Measuring female orgasm with MRI
Resolution
Refractory

17. Sexual Response (cont.)
Table 6.3 At a Glance Major Physiological Changes During Each of the Four Phases of the Sexual Response Cycle

18. Sexual Response (cont.)
Fig. 6.5a Major changes in external and internal male sexual anatomy during the sexual response cycle.

19. Sexual Response (cont.)
Fig. 6.5b Major changes in external and internal male sexual anatomy during the sexual response cycle.

20. Sexual Response (cont.)
Fig 6.5c Major changes in external and internal male sexual anatomy during the sexual response cycle.

21. Sexual Response (cont.)
Fig. 6.5d Major changes in external and internal male sexual anatomy during the sexual response cycle.

22. Sexual Response (cont.)
Fig. 6.5e Major changes in external and internal male sexual anatomy during the sexual response cycle.

23. Sexual Response (cont.)
Fig. 6.6a Major changes in the external female genitals during the sexual response cycle.

24. Sexual Response (cont.)
Fig. 6.6b Major changes in the external female genitals during the sexual response cycle.

25. Sexual Response (cont.)
Fig. 6.6c Major changes in the external female genitals during the sexual response cycle.

26. Sexual Response (cont.)
Fig. 6.6d Major changes in the external female genitals during the sexual response cycle.

27. Sexual Response (cont.)
Fig. 6.6e Major changes in the external female genitals during the sexual response cycle.

28. Sexual Response (cont.)
Fig. 6.7a Major changes in the internal female genitals during the sexual response cycle.

29. Sexual Response (cont.)
Fig. 6.7b Major changes in the internal female genitals during the sexual response cycle.

30. Sexual Response (cont.)
Fig. 6.7c Major changes in the internal female genitals during the sexual response cycle.

31. Sexual Response (cont.)
Fig. 6.7d Major changes in the internal female genitals during the sexual response cycle.

32. Sexual Response (cont.)
Fig. 6.7e Major changes in the internal female genitals during the sexual response cycle.

33. Sexual Response (cont.)
Orgasm issues
Grafenberg spot
area on lower front wall of vagina
sensitive to pressure
sometimes results in “ejaculation”

34. Sexual Response (cont.)
Fig. 6.9 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.

35. Sexual Response (cont.)
Fig. 6.8 Changes in the breasts during the sexual response cycle.

36. Sexual Response (cont.)
Aging & the sexual response cycle
older women
decreased vaginal lubrication; is slower
decreased flexibility of inner vagina
more rapid resolution

37. Sexual Response (cont.)
Aging & the sexual response cycle
older men
lengthened time to erection
loss of "ejaculatory inevitability"
more rapid resolution & longer
refractory period (hours to days)

38. Sexual Response (cont.)
Some differences between the sexes
greater variability in female response
male refractory period
females can have multiple orgasms