Presentation on theme: "Lighting the fire, Stoking the flame"— Presentation transcript:
1 Lighting the fire, Stoking the flame Arousal and ResponseLighting the fire, Stoking the flame
2 The Essential Hormones Two basic types – Steroid & NeuropeptideSteroid Hormones – secreted by the gonads and adrenal glandsExamples: 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 behaviorPerhaps the most significant:Oxytocin – the “love hormone”, it influences our erotic and emotional bonds
4 Testosterone – “the motivator” Men have 20 to 40 times moreEffects desire (libido) more than functionBut deficiencies do decrease sensitivity and desireCastration – the surgical removal of the testes causes dramatic reductions in sexual interest and desire
6 Less TestosteroneAntiandrogens – drugs which reduce testosterone levelsOccasionally given to sex offendersUsually decreases sexual interest and activityBut 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 slowedIf it starts after puberty, a marked decrease in desire follows
8 Estrogens and DesireTheir influence is undeniable but exact role is unclearResearch findings differ as to whether they increase desire
9 Females & Testosterone Testosterone clearly increases female sexual desire, sensitivity and activityTrue 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 lustTheresa Crenshaw “…. when a woman’s testosterone dwindles, so does her sex life.”
11 More On TestosteroneWomen have much less testosterone, but are much more sensitive to its effectsFor women, too much testosterone causes problems, such as “unwelcome” changes to secondary sexual characteristicsWomen 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 Therapycommonly available for mennow, slowly becoming an option for women
14 oxytocinA neuropeptide from the hypothalamus that effects sexual response and attractionBonding occurs through its releasemother/child – breast feedingsexual partners – arousal and responseAutistic 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 touchLevels increase within us as we go through the cycle of arousal to orgasmPresence 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 fantasiesOur culture has conditioned us to have certain preferences for what we consider physically attractiveWorld-wide prototypes?
18 Exemplars of BeautyA 2005 poll of plastic surgeons revealed the following as possessing the most desired:Nose – Nicole KidmanEyes – Catherine Zeta JonesLips – Angelina Jolie
22 The Limbic SystemA subcortical brain system of several related structures that impact sexual behaviorInvestigated through a number of studies
23 Olds (1950’s) Implanted electrodes in rat’s limbic system Allowed them to control stimulationWhen 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 systemOne man pushed his button over 1500/hr, described intense sexual pleasure, and complained whenever a “session” endedA woman reported similar experiences, even multiple orgasmic responses
25 The Hypothalamus Stimulation greatly arouses rats Its destruction crushes responseApparently, the medial preoptic area (MPOA) is especially sensitiveHeroin, morphine and other opiates suppress activity of the MPOADopamine and testosterone excite it
26 Serotonin’s Influence Presence inhibits sexual activitySeems to have the opposite effects of dopamineReleased after males ejaculate and blocks or dampens sensitivity to dopamine and oxytocinSSRI’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 TouchOur nerve endings are unevenly distributed, locations which are most sexually responsive are called ourPrimary Erogenous Zones, which include our genitals, lips, buttocks, inner thighs, neck, mouth, perineumBut we find tremendous variability
29 Secondary Erogenous Zones other areas touched within the context of sexual intimacyCould be anywhere on the bodyEstablished through classical conditioning?
30 Vision Very important in our society Emphasis on physical attractiveness, grooming, clothes and cosmeticsAre 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, and3) measured the right way,STRONG similarities between men and women were foundthough 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 mammalsThe vomeronasal system relates to their usePresent in humans,But is it functional?
34 What Works Smells that arouse Women – licorice, banana nut bread, cucumbersMen – lavender, pumpkin pie, doughnuts
35 What Doesn’tWomen – barbecued meat, men’s cologne’sMen – Nothing
36 AphrodisiacsSubstances 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 responseThe 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 AnaphrodisiacsBirth control pills decrease free testosterone levelsNicotine 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 StagesDesire – a prelude to physical sexual response, ignored by Masters and JohnsonExcitementOrganism
43 Masters and JohnsonSexology TrailblazersDirect Observation
44 Masters and Johnson’s Four Phases Excitementboth men and women:muscle tension, anatoniaincreased heart rate/blood pressureengorgementsex flush
45 More Excitement Women: engorgement lubrication enlargement Men: erectionenlargement/elevation
46 Stage II - PlateauThe acceleration of processes begun in the excitement phaseFemalesthe orgasmic platform – the significantly engorged outer 1/3 of the vaginaLasts from a few seconds to a few minutes
47 Phase III - Orgasm Involuntary muscle spasms Blood pressure, respirations, heart rate peaksMales – 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 clitoralThis view, influential for decades, has been abandonedMasters and Johnson established that there is just one kind of female orgasm, though most arise from clitoral stimulation
51 Return to the “G” SpotOnce found, manual stimulation produces variable sensationsIntense pleasure and orgasm usually followsSome women even experience ejaculationBut the source of the fluid is uncertain
53 Finally, ResolutionProcess through which sexual systems return to a nonexcited stateWhile in most respects the sexes experience this process similarly, men go through a refractory period during which they cannot experience another orgasm
54 Aging and the Response Cycle Function continues but intensity declinesOlder women – longer for lubricationOccasional decreases in desire, sensitivity, and capacityOlder men – longer for erection/orgasmgreater controllonger refractory period
55 Where the Sexes DifferDespite surprising similarities, some distinctions remainVariabilityWomen have three patterns within the sexual response cycleMen just one
56 The Male Refractory Period Why?Evolution based ? Give another guy a chance ?Dependent on midbrain- hypothalamus pathway ?
57 Multiple Orgasms Women can have several, in succession But just 14 to 16% ?Masters and Johnson say most can have 5-6 !Men can too ?!?