Arousal and Response

1. Arousal and Response Lighting the fire, Stoking the flame

2. The Essential Hormones • Two basic types – Steroid & Neuropeptide • Steroid Hormones – secreted by the gonads and adrenal glands • Examples: testosterone, estrogen, etc. • Not simply male or female – both sexes produce each, but in varying amounts

3. Neuropeptide Hormones • Produced in the brain, they influence sexuality and behavior • Perhaps the most significant: • Oxytocin – the “love hormone”, it influences our erotic and emotional bonds

4. Testosterone – “the motivator” • Menhave 20 to 40 times more • Effects desire (libido) more than function • But deficiencies do decrease sensitivity and desire • Castration – the surgical removal of the testes causes dramatic reductions in sexual interest and desire

5. Testosterone uses

6. Less Testosterone • Antiandrogens – drugs which reduce testosterone levels • Occasionally given to sex offenders • Usually decreases sexual interest and activity • But sometimes offenders assault for other reasons , such as anger, power and control

7. Hypogonadism – testosterone deficiency due to diseases of the endocrine system • If it begins before puberty, development is slowed • If it starts after puberty, a marked decrease in desire follows

8. Estrogens and Desire • Their influence is undeniable but exact role is unclear • Research findings differ as to whether they increase desire

9. Females & Testosterone • Testosterone clearly increases female sexual desire, sensitivity and activity • True even for women after menopause or removal of the ovaries

10. Women with “normal” levels of sexual activity and hormones who receive additional testosterone show significant increases in sexual arousal, sensation and even lust • Theresa Crenshaw “…. when a woman’s testosterone dwindles, so does her sex life.”

11. More On Testosterone • Women have much less testosterone, but are much more sensitive to its effects • For women, too much testosterone causes problems, such as “unwelcome” changes to secondary sexual characteristics • Women see levels fall more rapidly after menopause than male’s more gradual decline

12. If measured, it is “free” (unattached) testosterone that matters, not “total” • Testosterone Replacement Therapy commonly available for men now, slowly becoming an option for women

13. Marketing Testosterone

14. oxytocin • A neuropeptide from the hypothalamus that effects sexual response and attraction • Bonding occurs through its release mother/child – breast feeding sexual partners – arousal and response • Autistic children have low levels and corresponding difficulties forming bonds and expressing love

16. Oxytocin and Love • Release is triggered by touch • Its circulation increases the skins sensitivity to touch • Levels increase within us as we go through the cycle of arousal to orgasm • Presence remains in blood stream after orgasm facilitating pair bonding

17. The Brain – Our Most Sexual Organ? • Our cerebral cortex stores memories and images producing powerful fantasies • Our culture has conditioned us to have certain preferences for what we consider physically attractive • World-wide prototypes?

18. Exemplars of Beauty • A 2005 poll of plastic surgeons revealed the following as possessing the most desired: • Nose – Nicole Kidman • Eyes – Catherine Zeta Jones • Lips – Angelina Jolie

19. Nose

20. Eyes

21. Lips

22. The Limbic System • A subcortical brain system of several related structures that impact sexual behavior • Investigated through a number of studies

23. Olds (1950’s) • Implanted electrodes in rat’s limbic system • Allowed them to control stimulation • When given the chance, rats will “dial their own number” until they reach exhaustion, even up to several thousand times an hour • “pleasure centers”

24. Heath (1972) • Humans with a variety of disorders were allowed to self-stimulate their limbic system • One man pushed his button over 1500/hr, described intense sexual pleasure, and complained whenever a “session” ended • A woman reported similar experiences, even multiple orgasmic responses

25. The Hypothalamus • Stimulation greatly arouses rats • Its destruction crushes response • Apparently, the medial preoptic area (MPOA) is especially sensitive • Heroin, morphine and other opiates suppress activity of the MPOA • Dopamine and testosterone excite it

26. Serotonin’s Influence • Presence inhibits sexual activity • Seems to have the opposite effects of dopamine • Released after males ejaculate and blocks or dampens sensitivity to dopamine and oxytocin • SSRI’s have many negative effects on sexuality

27. The Senses • Many sources of erotic stimulation • Their influence leads to tremendous variety and amazing sexual complexity

28. Touch • Our nerve endings are unevenly distributed, locations which are most sexually responsive are called our Primary Erogenous Zones, which include our genitals, lips, buttocks, inner thighs, neck, mouth, perineum • But we find tremendous variability

29. Secondary Erogenous Zones other areas touched within the context of sexual intimacy • Could be anywhere on the body • Established through classical conditioning?

30. Vision • Very important in our society • Emphasis on physical attractiveness, grooming, clothes and cosmetics • Are males more aroused by visual stimuli?

31. Kinsey’s survey said, “YES!” But once women were presented with the: 1) right stimuli, 2) in the right settings, and 3) measured the right way, STRONG similarities between men and women were found though women’s self-reports say no

32. Smell • Are genitals smells arousing or awful? • Depends largely on where you live and your acceptance or rejection of fragrance claims.

33. Pheromones • Odors secreted by the body which relate to reproduction • Common for mammals • The vomeronasal system relates to their use • Present in humans, • But is it functional?

34. What Works • Smells that arouse • Women – licorice, banana nut bread, cucumbers • Men – lavender, pumpkin pie, doughnuts

35. What Doesn’t • Women – barbecued meat, men’s cologne’s • Men – Nothing

36. Aphrodisiacs • Substances that supposedly increase sexual desire and capacity

37. Do They Deliver? • Many claims – little evidence • Alcohol, amphetamines, barbiturates, cocaine and marijuana reduce inhibitions but also sexual response • The power of suggestion seems key

38. Hope on the Horizon? • One substance, yohimbine hydrochloride (sap of the tropical evergreen) does increase desire and performance

39. Anaphrodisiacs • Substances which inhibit sexual desire and performance • Many things “work” • Drugs such as opiates, tranquilizers, and antidepressants inhibit ejaculation and cause erectile problems in males and decrease orgasmic capacity for females

40. Other Anaphrodisiacs • Birth control pills decrease free testosterone levels • Nicotine both decreases vasocongestion and reduces testosterone levels

41. Sexual Response • A highly individualized process • Research has revealed common patterns of physiological changes

42. Kaplan’s Three Stages • Desire – a prelude to physical sexual response, ignored by Masters and Johnson • Excitement • Organism

43. Masters and Johnson Sexology Trailblazers Direct Observation

44. Masters and Johnson’s Four Phases • Excitement both men and women: muscle tension, anatonia increased heart rate/blood pressure engorgement sex flush

45. More Excitement • Women: engorgement lubrication enlargement • Men: erection enlargement/elevation

46. Stage II - Plateau • The acceleration of processes begun in the excitement phase • Females the orgasmic platform – the significantly engorged outer 1/3 of the vagina • Lasts from a few seconds to a few minutes

47. Phase III - Orgasm • Involuntary muscle spasms • Blood pressure, respirations, heart rate peaks • Males – emission then expulsion

49. Are the males’ and females’ experiences different ? • Descriptions are indistinguishable.

50. Are some Orgasms superior ? • Freud thought so, claiming that vaginal orgasms are more “mature” than clitoral • This view, influential for decades, has been abandoned • Masters and Johnson established that there is just one kind of female orgasm, though most arise from clitoral stimulation