Sexual Arousal and Response

1. Sexual Arousal and Response

2. Factors influencing arousal and response • Hormones • Brain’s capacity to create images and fantasies • Emotions • Sensory processes • Level of intimacy between two people • Sexual expression is influenced by interplay of: • Social, emotional, and cognitive factors • Hormones • Brain neurons • Spinal reflexes

3. Role of Hormones in Sexual behavior • Steroids: the sex hormones and hormones of the adrenal cortex • Both 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 amounts • The dominant androgen is testosterone and men produce about 20 to 40 times more testosterone than women • Estrogens are produced by the ovaries by females and in small amounts by the testes for males.

4. hormones • Neuropeptide 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 bonding • Levels increase as a person moves through sexual response cycle from initial excitement to orgasm for both sexes • Stimulates uterine wall contraction for women • Facilitates milk “let down” during breastfeeding • Autistic 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-being • Maintaining thickness and elasticity of vaginal lining • Vaginal lubrication • Desire-though some studies show in high doses can decrease it • Pleasure • Orgasmic capacity • Testosterone plays an important role as the major libido hormone

7. The Brain and Sexual Arousal • Mediator of thoughts, emotions, and memories • Sexual arousal can occur without any sensory stimulation through fantasies • Cerebral cortex; outer layer and thinking center of the brain that controls functions like reasoning, language, and imagination • Limbic system; subcortical brain system composed of interrelated structures (cungulategyrus, amygdala, hippocampus, and parts of the hypothalmus) that influence sexual behavior in humans and animals • Studies show direct limbic stimulation produced intense sexual pleasure and orgasmic responses • In rats, hypothalmus stimulation triggered erection and ejaculation

8. Brain and Arousal • Dopamine; a neurotransmitter that facilitates sexual arousal and activity; testosterone stimulates the release of dopamine in both sexes • Serotonin; inhibits sexual arousal and activity • Male 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 • Touch • Most frequent source of arousal than any other stimulus • Primary erogenous zones: areas of the body densely covered with nerve endings • Genitals, 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 experience • Vision • Smell • Taste • Hearing • What senses has greatest impact on sexual arousal and interaction? Do men and women differ in terms of what senses predominate during sexual intimacy?