BMFT 651: Sexual Therapy February 10, 2010

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)

Prenatal Sexual Development

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

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

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

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

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

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.

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

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

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

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

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

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.

Break (9:15-9:30)

Freeks n’ Geeks

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?

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.

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

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

Sexual Arousal & Response

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

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

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

The Senses & Sexual Arousal Touch Sight Smell Hearing Taste

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

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

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

Sexual Arousal & Response

Sexual Arousal & Response

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)

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