1. BMFT 651: Sexual Therapy February 10, 2010

2. Agenda Prenatal sexual development (8:00-9:15) Break (9:15-9:30)
Freeks n’ Geeks (9:30-10:00)
Sexual arousal & response (10:00-10:50)

3. Prenatal Sexual Development

4. Sex vs. Gender Sex = biological maleness & femaleness
Gender = psychological & sociocultural characteristics associated with sex
Gender assumptions = assumptions about how people should behave based on their biological sex
Gender identity = how one perceives oneself as being male or female
Gender role = collection of attitudes & behaviors considered normal for people of a certain sex

5. Typical Prenatal Differentiation
Chromosomal sex
Gonadal sex
Hormonal sex
Sex of internal reproductive organs
Sex of external genitals
Sex differentiation of the brain

6. Chromosomal Sex
Biological sex determined by the chromosomal makeup of the sperm that fertilizes the ovum
23 pairs of chromosomes
22 pairs are the autosomes - matched sets that don’t differ between males & females
The sex chromosome pair
XX - female
XY - male

7. Gonadal Sex
Gonads are the same in males & females during first several weeks after conception
Differentiation begins at 6 weeks
Males - gonads transform into testes
Females - gonads transform into ovaries

8. Hormonal Sex Gonads release hormones into blood stream
Ovaries - estrogen & progestational compounds
Testes - androgens such as testosterone

9. Sex of Internal Reproductive Structures
8 weeks after conception
Androgens secreted by testes stimulate Wolffian ducts to develop into vas deferens, seminal vesicles, & ejaculatory ducts
Mullerian-inhibiting substance, secreted by testes, causes the Mullerian duct to disappear in males
In absence of androgens, fetus develops female structures including the fallopian tubes, uterus, & the inner third of the vagina, & the Wolffian duct system degenerates.

10. Sex of External Genitals
Before 6th week, external genitals are undifferentiated.
In males, DHT is released which stimulates the development of the scrotum & penis.
In absence of DHT, the clitoris, labia minora, & labia majora develop.
Differentiation process complete by 12th week

14. Sex Differentiation of the Brain
In absence of testosterone, female hypothalamus develops receptor cells that are sensitive to estrogen.
Nucleus of the strias terminalis (BST) - larger in heterosexual men than in heterosexual women
Preoptic area (PO) - larger in men than women

15. Atypical Prenatal Differentiation
Inter-sexed/pseudo-hermaphrodites
Gonads match chromosomal sex
Internal & external reproductive anatomy - mixture of male & female structures
True hermaphrodites
Both ovarian & testicular tissue in their bodies
External genitals are often a mixture of male & female structures

16. Sex Chromosome Disorders
Turner’s Syndrome
One unmatched X chromosome (XO)
Normal female external genitals
Internal reproductive structures do not develop fully
Klinefelter’s Syndrome
2 X chromosomes & one Y (XXY)
Undersized external male genitals

17. Hormonal Disorders Androgen Insensitivity Syndrome
Chromosomally normal males (XY)
Insensitive to testosterone & other androgens
Develop female external genitals of normal appearance
Fetally Androgenized Females
Chromosomally normal female (XX)
Excessive exposure to androgens
Develops external genitalia resembling those of a male

19. Hormonal Disorders DHT Deficient Males Chromosomally normal male (XY)
Genetic defect that prevents conversion of testosterone into DHT
Develops external genitalia resembling those of a female
At puberty, when testosterone levels increase, penis & testes often descend.

20. Break (9:15-9:30)

21. Freeks n’ Geeks

23. Short Write Go to the blog, and post your answer to this question:
If you had a child who was a true hermaphrodite, would you choose to assign a gender identity and perform the surgical and/or hormonal treatments consistent with that identity? If so, what gender would you select? Why?

24. Transsexualism & Transgenderism
Transsexual - a person whose gender identity is opposite to his/her biological sex
Feeling trapped in a body of the wrong sex
Gender dysphoria
Transgendered - people whose appearance and/or behaviors do not conform to traditional gender roles
Difference between the two - Transgendered people do not want to change their physical bodies to create a better fit with personal and/or societal role expectations.

25. Variations of Transgenderism
Androphilic (attracted to males) men - cross-dress & assume a female role either to attract men (often heterosexual men) or to entertain
Gynephilic (attracted to females) men - have urges to become female but are reasonably content to live in a male role that may include being married & frequent cross-dressing or socializing as a woman
Gynephilic (attracted to females) women - manifest masculine qualities but never seek sex reassignment

26. Gender Identity & Sexual Orientation
Gender identity is who we are - our subjective sense of being male or female, or some combination of the two
Sexual orientation - which of the sexes we are emotionally and sexually attracted to

27. Sexual Arousal & Response

28. Hormones in Male Sexual Behavior
Testosterone linked to sexual desire & sexual functioning
Castration - reduced sexual desire but may continue to function sexually
Antiandrogens reduce sexual desire & sexual activity
Hypogonadism - reduced sexual desire

29. Hormones in Female Sexual Behavior
Role of estrogens remains unclear
Testosterone - major libido hormone in females
Clear relationships between level of testosterone & sexual desire, genital sensitivity, & frequency of sexual activity

30. The Brain & Sexual Arousal
Sexual arousal can occur through fantasy without any physical stimulation.
Cerebral cortex - controls higher mental processes; where fantasies come from
Limbic system
Research of James Olds - pleasure centers
Research of Robert Heath

31. The Senses & Sexual Arousal
Touch
Sight
Smell
Hearing
Taste

32. Sexual Arousal & Response
Kaplan’s three-stage model
Desire
Excitement
Orgasm

33. Sexual Arousal & Response
Master’s & Johnson’s four-stage model
Excitement
Muscle tension & increase in heart rate
Engorgement of sexual anatomy
Sex flush - pink/red rash that most commonly appears on chest/breasts
May last for less than a minute to several hours
Plateau
Sexual tension continues to mount until reaching point of orgasm
Heart rate, blood pressure, muscle tension, & vasocongestion increase

34. Sexual Arousal & Response
Master’s & Johnson, cont.
Orgasm
Ejaculation - emission & expulsion
Women may reach plateau without reaching orgasm while men almost always orgasm after reaching plateau
Shortest phase - typically lasting only a few seconds
Resolution
Sexual systems return to non-excited state
Refractory period

35. Sexual Arousal & Response

36. Sexual Arousal & Response

38. Differences between the Sexes
Greater variability in female response, but males also differ.
Male refractory period
Certain minimum time must elapse before they can experience another orgasm
Multiple orgasms
Surveys suggest that 14-16% of women experience multiple orgasms
Less common among males but possible
Many men have been conditioned to “get it over with” as quickly as possible to avoid getting caught (masturbation)

39. Next Week Topics Sexuality through the life cycle Sexual behavior
Reading
Stevenson & Elliot