Sexual Arousal and Response Chapter 5

Learning Objectives Making Sense of Sex Aphrodisiacs Sexual Response and the Brain: Cerebral Sex? Sex Hormones and Sexual Behavior Sexual Response

Making Sense of Sex Senses All the senses can be responsive to stimuli that enhance or diminish one’s sexual arousal

Making Sense of Sex Visual stimuli are very important to human sexual arousal and response Men appear to be more responsive to visual stimuli Both men and women can be sexually aroused by mediated erotica Men are more interested Vision

Making Sense of Sex Odors can be sexually attractive or off-putting Play a role in selection of sex partners Pheromones are odorless chemicals detected by the nose Contributes to menstrual synchrony in women Smell

Making Sense of Sex Sense of touch has most direct effect on arousal Erogenous zones are areas of the body that are especially sensitive to stimulation, such as strokes and caresses Primary erogenous zones are particularly sensitive because they are richly endowed with nerve endings Secondary erogenous zones are areas of the body that become especially sensitive through experience The Skin Senses

Making Sense of Sex Tastes seem to play a minimal role in sexual arousal and response Some people are aroused by taste of genital secretions Taste

Making Sense of Sex Auditory stimuli can have a strong influence on sexual arousal and behavior A person’s voice, certain music, certain “dirty” words, etc., can be turn-on or turn-off Hearing

Aphrodisiacs Anaphrodisiacs Drugs or other agents that are sexually arousing or that increase sexual desire Foods resembling male genitals Drugs that affect the brain’s receptors for dopamine Testosterone Good nutrition and exercise Novelty Substances that inhibit or destroy sexual arousal and response Tranquilizers and barbiturates, which depress the central nervous system Drugs for hypertension Some antidepressants Nicotine Antiandrogen drugs, substances that decrease the level of androgens in the bloodstream Anaphrodisiacs

Psychoactive Drugs Alcohol A small amount can be stimulating, but large amounts often curb sexual arousal & response Reduces sexual inhibitions Binge drinking associated with high-risk sexual behavior Can create feelings of euphoria

Psychoactive Drugs Hallucinogens No proven connection between such drugs and sexual arousal and response Effects may depend on prior use, attitudes/expectations, and amount

Psychoactive Drugs Stimulants Activate the central nervous system, but may not have specific sexual effects Can elevate mood, which could increase sexual pleasure Regular users may need the drug to become sexually aroused or may lose the ability to enjoy sex

Alcohol stimulates sexual desire and behavior. Critical Thinking Alcohol stimulates sexual desire and behavior. Agree or Disagree Critical Thinking

Sexual Response & the Brain Parts of the brain play a central role in sexual arousal and response Fig. 5.2. Parts of the brain involved in sexual functioning (p. 135).

Sexual Response & the Brain Cerebral cortex The part of the brain that is active when people engage in sexual thoughts, images, wishes, and fantasies Transmits messages through spinal cord Provides sense of conscious sense of self Makes judgments about sexual behavior

Sexual Response & the Brain Limbic system Structures active in memory, motivation, and emotion Hypothalamus – regulates body temperature, drives, hormones, and emotion

Sexual Response & the Brain Electrical stimulation of certain parts of the limbic system has led to reports of sensations similar to sexual gratification Research suggests “pleasure centers” may exist Copyright © 2011 Pearson Education, Inc. All rights reserved.

Critical Thinking If you electrically stimulate part of a rat’s brain, it mechanically runs through a mating routine. Does it seem useful or wise to apply this research finding to humans?

Sex Hormones & Sexual Behavior Hormones are chemicals secreted by the endocrine system Regulate various bodily functions Hypothalamus and pituitary gland regulate gonadal secretion of sex hormones Testosterone in males Estrogen and progesterone in females Female and male sex hormones are present in both women and men Release of sex hormones at puberty results in reproductive maturity and development of secondary sex characteristics

Sex Hormones & Sexual Behavior Sex hormones have Organizing effects Exert influence on the type of behavior being expressed Activating effects Ability to perform the behavior Frequency and motivation to perform the behavior

Sex Hormones & Sexual Behavior Prenatal hormones Play a role in sexual differentiation of genitalia and brain structures Role in patterning sexual behavior in adulthood remains unknown

Sex Hormones & Sexual Behavior Male Sexual Behavior Male hormones influence sex drive & response Men who are surgically or chemically castrated typically show a gradual decline in sexual desire Hypogonadism Condition characterized by abnormally low levels of testosterone production, results in a loss of sexual interest and a reduction in sexual activity No one-to-one correspondence to hormone levels and sex drive

Sex Hormones & Sexual Behavior Female Sexual Behavior Estrogen and progesterone activate changes that occur during puberty and regulate the menstrual cycle, but do not seem to influence sexual motivation or response in human females Women who have ovariectomies (surgical removal of the ovaries) continue to be sexually active Androgens appear to have more of an effect on both men’s and women’s sexual response

Sexual Response Excitement phase Plateau phase Orgasmic phase Resolution phase Masters and Johnson’s model of sexual response consists of four phases

Sexual Response Excitement Phase Erections in men Vaginal lubrication and genital swelling in women Muscle tension and increases in heart rate in both females and males Sex flush is a reddish rash that may appear on the chest or breasts late in the excitement phase

Sexual Response Plateau Phase Increases in vasocongestion, muscle tension, heart rate, and blood pressure Orgasmic platform, which is the thickening of the walls of the outer third of the vagina, due to vasocongestion Sex skin, which is the reddening of the labia minora Rapid breathing and heart rate, blood pressure increases

Sexual Response Orgasmic Phase Male orgasms consist of two stages of muscular contractions 1st stage – contractions push seminal fluid into urethral bulb 2nd stage – ejaculation

Sexual Response Orgasmic Phase Female orgasms manifest as 3 to 15 contractions of the pelvic muscles surrounding vaginal barrel Spacing of contractions more variable in women than in men Uterus and anal sphincter contract rhythmically

Sexual Response Orgasmic Phase In both men and women, muscle spasms occur throughout the body and blood pressure and heart rate peak Orgasm is a subjective experience

Sexual Response Resolution Phase The fourth phase of the sexual response cycle, during which the body gradually returns to its pre-aroused state Resolution takes longer when people do not reach orgasm Blood is released from engorged areas, myotonia dissipates, and blood pressure, heart rate, & respirations return to normal Refractory period for men Period of time following an orgasm during which an individual is no longer responsive to sexual stimulation Men experience in varying degrees

Sexual Response Fig. 5.3. Levels of sexual arousal during the phases of the sexual response cycle (p. 141).

Sexual Response Kaplan’s Three Stages of Sexual Response: Desire Excitement Orgasm The stages are independent and their sequence is variable This model is notable for identifying desire as a separate phase of sexual response Useful for identifying and treating sexual dysfunctions Kaplan’s Three Stages of Sexual Response: An Alternative Model

Controversies about Orgasms One or more additional orgasms following the first, which occur within a short period of time and before the body has returned to a pre-plateau level of arousal Women are more capable of multiple orgasms, by definition, than men are because they do not experience a refractory period Men may experience multiple orgasms if they are dry orgasms Multiple Orgasms

Controversies about Orgasms Evolutionary perspective suggests that female orgasm will lead to conception by holding the sperm within the body Orgasms Increase the Likelihood of Conception?

Controversies about Orgasms Freud Clitoral orgasm Vaginal orgasm Masters & Johnson Only one type of orgasm Singers Vulval orgasm Uterine orgasm Blended orgasm How many kinds of orgasms do women have? No consensus yet