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
QuickTime™ and a
decompressor
are needed to see this picture.
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