2 Factors influencing arousal and response HormonesBrain’s capacity to create images and fantasiesEmotionsSensory processesLevel of intimacy between two peopleSexual expression is influenced by interplay of:Social, emotional, and cognitive factorsBrain neuronsSpinal reflexes
3 Role of Hormones in Sexual behavior Steroids: the sex hormones and hormones of the adrenal cortexBoth sexes produce male sex hormones (androgens) and female sex hormones (estrogens)Androgens: for men, 95% are produced by the testes; for women, the ovaries and adrenal glands produce androgens in equal amountsThe dominant androgen is testosterone and men produce about 20 to 40 times more testosterone than womenEstrogens are produced by the ovaries by females and in small amounts by the testes for males.
4 hormonesNeuropeptide hormones are the chemicals of emotion produced in the brain. They influence arousal, attraction, and response components of sexuality.Oxytocin, the neuropetide produced in the hypothalmus: “love hormone” influencing emotional and erotic attraction, attachment, and bondingLevels increase as a person moves through sexual response cycle from initial excitement to orgasm for both sexesStimulates uterine wall contraction for womenFacilitates milk “let down” during breastfeedingAutistic children have low levels of oxytocin, which is associated with reduced ability to form social attachments and express love
5 Sex Hormones in Male Sexual Behavior Studies indicate testosterone has a greater effect on male desire than sexual functioning.However, it also is involved with sensitivity, so a deficiency can decrease sexual pleasure.Studies conducted with men who have been castrated have provided information about testosterone’s role in sexual functioning.Antiandrogens: a class of drugs used to treat sex offenders and certain medical conditions like prostate cancer
6 Sex Hormones in Female Sexual Behavior Estrogen contributes to:General sense of well-beingMaintaining thickness and elasticity of vaginal liningVaginal lubricationDesire-though some studies show in high doses can decrease itPleasureOrgasmic capacityTestosterone plays an important role as the major libido hormone
7 The Brain and Sexual Arousal Mediator of thoughts, emotions, and memoriesSexual arousal can occur without any sensory stimulation through fantasiesCerebral cortex; outer layer and thinking center of the brain that controls functions like reasoning, language, and imaginationLimbic system; subcortical brain system composed of interrelated structures (cungulate gyrus, amygdala, hippocampus, and parts of the hypothalmus) that influence sexual behavior in humans and animalsStudies show direct limbic stimulation produced intense sexual pleasure and orgasmic responsesIn rats, hypothalmus stimulation triggered erection and ejaculation
8 Brain and ArousalDopamine; a neurotransmitter that facilitates sexual arousal and activity; testosterone stimulates the release of dopamine in both sexesSerotonin; inhibits sexual arousal and activityMale ejaculation causes a release of serotonin, which temporarily inhibits the release of dopamine. It also suppresses arousal by blocking oxytocin.Antidepressant medication, selective serotonin reuptake inhibitors (SSRIs), increase serotonin levels in the brain and may interfere with libido and sexual response.
9 The Senses and Sexual Arousal TouchMost frequent source of arousal than any other stimulusPrimary erogenous zones: areas of the body densely covered with nerve endingsGenitals, buttocks, anus, perineum, breasts (particularly nipples), inner surfaces of thighs, armpits, navel, neck, ears, and the mouth (lips, tongue, entire oral cavity)Secondary erogenous zones: areas that have become erotically sensitive through learning and experienceVisionSmellTasteHearingWhat senses has greatest impact on sexual arousal and interaction? Do men and women differ in terms of what senses predominate during sexual intimacy?