Chapter 4: Similarities and Differences in Our Sexual Responses

1. Chapter 4: Similarities and Differences in Our Sexual Responses For use with Human Sexuality Today (4th Ed.) Bruce King Slides prepared by: Traci Craig

2. Chapter Overview • Measurement of Sexual Responses • Sexual Response Cycle • Controversies about Orgasm • Penis Size • Aphrodesiacs • Afterwards • Sexuality and People with Disabilities

3. Measurement of Sexual Response • Masters & Johnson • Observed 10,000 sexual episodes • 312 men and 382 women from local community • 18-89 years old • Multiple sessions with participants • Measured physiological responses • Heart rate, blood pressure, muscle tension, respiration, and brain waves

4. Measurement Devices • Penile strain gauge—fits around base of penis, tube filled with mercury transmits electric current, measures changes in circumference. • Vaginal photoplethysmograph—fits into the vagina and has a light and photocell to record blood volume in the vaginal walls.

5. Sexual Response Cycle • Master’s and Johnson—4 phases • Other models of sexual response—range in number of phases • 3 Phase Model by Helen Kaplan (1979) • General agreement about the specific responses.

6. Desire • Specific sensations that move the individual to seek out or be receptive to sexual experiences. • Physiological responses in the absence of psychological desire and vice versa. • 8 sexual motivations: feel value, show value, relieve stress, nurture, feel power, experience power, experience pleasure, procreate.

7. Excitement: Men • Nerve impulses cause dilation (via cyclic GMP) • Sacral erection center.

8. Excitement: Men • Physical sign of arousal: erection • Vasocongestion of the corpora cavernosa and the corpus spongiosum. • Increased heart rate/blood pressure. • Testicles enlarge. • Nipple erection.

9. Excitement: Women Labia majora flatten and move apart. Clitoris enlarges, becomes visible. Nipples erect/Breasts enlarge.

10. Excitement: Women • Vasocongestion: vaginal walls become engorged with blood. • Vaginal walls balloon out. • Cervix and uterus move pull up. • Vaginal lubrication—often unaware of this process, not a sign of readiness.

11. Plateau: Men • Diameter of penis continues to increase. • Testicle size increases from 50-100%. • Back surface of the testicles touch the perineum. • Cowper’s gland secrete clear fluid that appears at tip of the penis. • Sex tension flush on various areas of the skin.

12. Plateau: Women Clitoris pulls back toward pubic bone beneath the clitoral hood. • Sex-tension flush • Breasts swellobscures nipple erection. • Labia minora engorgedarker in color.

13. Plateau: Women • Vaginal opening narrows 30-50% (orgasmic platform) • Secretion of fluids slows. • Inner 2/3 of vagina expand (tenting effect)

14. Orgasm • Sudden discharge of sexual tension. • Men and women have similar descriptions. • Rhythmic muscular contractions in specific parts of the body occurring every .8 seconds. • Contractions not highly correlated with reports of orgasm. • Primarily a perceptual experience.

15. Orgasm: Men • 2 stages: Emission and Expulsion • Emission—muscular contractions of the vas deferens, prostate gland, and seminal vesicles. Urethral bulb swells with semen. Inevitability of ejaculation. • Expulsion—Contractions in the urethra and muscles at the base of the penis force semen from the penis (ejaculation).

16. Retrograde Ejaculation • Sphincter muscles that prevent urine from entering the urethra open. • Sphincter muscles that allow semen to pass through the urethra close. • Thus, semen is expulsed into the bladder.

17. Ejaculation is not Orgasm • Ejaculation and Orgasm are two different events. • Orgasm is the subjective pleasurable experience. • Ejaculation is the release of semen from the body. • Prior to puberty boys can have orgasm, but do not ejaculate.

18. Orgasm: Women • Historically—women were not thought capable of orgasm. • Women who orgasm retain more sperm if she orgasms before her partner ejaculates.

19. Resolution: Men • Loss of erection • Decrease in testicle size • Refractory period—time before able to reach another orgasm. • Coolidge effect

20. Resolution: Women • Multiple orgasms • 10% of women report never having orgasm. • Breasts and labia return to normal. • Sex flush disappears • Uterus comes down and vagina shortens.

21. Orgasm Controversies • Some women do not regularly have orgasm. • Types of Female Orgasm • Clitoral stimulation (Freud “immature”/tenting type) • Vaginal orgasms (Freud “mature”) • Very little feeling in inner 2/3 of vagina • Grafenberg (G) spot—dime size area on front wall of the vagina swells when stimulated. (A-frame type) • Women have longer orgasms (over a minute)

22. Do women ejaculate? • Fluid emitted from the Skene’s glands located in the urethra. • Skene’s gland (same tissue as prostate) • Prostate like secretions. • Strong PC muscles, stimulation of the G-spot. • More research needed for conclusive evidence.

23. Multiple Orgasms & Men • Dry orgasms or mini-orgasms that are not paired with ejaculation. • This is self-report and also needs more research to be definitive.

24. Penis size: Does it matter? • Flaccid penises vary in size more than erect penises. • Recent studies (not relying on self-measurement): avg. 4.5” to 5.75” long. • Vagina average depth when aroused is 6” • Unimportant to women in self-report and in arousal to photos of various sized penises. • No.

25. Aphrodisiacs • Spanish fly (cantharides): Can cause inflammation and irritation of the urinary and genital tracts. Can results in painful erections, ulcers, diarrhea, death. • Alcohol: makes you less inhibited, but impairs nervous system responses needed for engaging in sex. It is an anaphrodisiac.

26. Aphrodisiacs • Cocaine—CNS stimulant, erectile failure, difficulty reaching orgasm, heavy usetotal sexual dysfunction. • Amphetamines—burst of energy, but will decrease sexual functioning. • Amyl nitrate—intensify sensation, dangerous with heart or blood pressure problems.

27. Aphrodisiacs • Marijuana—enhances relaxation and increases awareness to touch, erectile problems, lower testosterone levels and sperm production. • Ecstasy(MDMA)—Causes permanent brain damage, psychotic episodes. • Yohimbine hydrochloride—positive impact on psychologically caused impotence in men.

28. And Afterwards? • Whoever gets there first can continue to pleasure their partner via a variety of behaviors. • 72% of women responded that they would forgo the act of sex if they could be held closely. • Sex involves touch which is important for everyone.

29. People with Disabilities • Society’s attitude about disabled individuals is the largest barrier that disabled people face in developing sexual relationships. • Disabled does not mean asexual. • Reasons for sexual relations go beyond genital sensations. • Sex education for the mentally disabled may be very important to helping them lead satisfying lives.