Chapter 4 part 2 Flashcards
What is an example of a behavior that is the result of both organizational and activational effects?
Male rodent mating behavior is organized before birth and activated in adulthood by steroid hormones
What is an example of a behavior that is the result of only organizational effect?
Rough-and-tumble play in rhesus monkeys is influenced by early hormone exposure but not activated later
What is an example of a behaviour that is the result of only activational effect?
Electrical discharge patterns in electric fish
What is an example of a behavior that is not hormonally influenced?
human gender shaped by social environment
What are the three main treatment approaches to ambiguous genitalia?
- Match External Genitalia to Genetic Sex
- Perform surgical and endocrine treatments to align genitalia with XX or XY chromosomes
- Assumes genetic sex determines gender identity and role
- Base decision on genitalia appearance
- If genitalia appear more male/female, surgery aligns with that appearance
- Assumes early biological factors are less important than rearing environment
- Wait for child to decide
- more considered today
What is the intersex society of north america (ISNA) recommendation for intersex infants?
avoid irreversible surgery in infancy
What are the two main approach to deal with intersex patient and their differences?
Concealment-Centered Model→ Traditional model
- intersex as pathological condition
- require immediate medical intervention
- gender determined by nurture
- secrecy→ often withholding info from child
- parental distress over autonomy of intersex individual
Patient-centered Model→ modern ethical approach
- intersex as a natural variation
- surgeries be delayed
- gender identity cannot always be predicted at birth
- full disclosure of medical history to intersex individuals
When does the sexual differentiation occur during the pregnancy?
end of first semester
What does a high sex steroid hormone levels lead to during pregnancy?
masculinization and defeminization
What is congenital adrenal hyperplasia (CAH)?
- Excess androgen exposure
- Masculinization of behavior
What is the 5α-Reductase Deficiency?
- Reduced conversion of testosterone to DHT
- Ambiguous genitalia, delayed masculinization
What is the Complete or Partial Androgen Insensitivity Syndrome (CAIS/PAIS)?
- Resistance to androgens
- Feminization despite XY genotype
What are the potential consequences of maternal hormone treatment ?
Maternal Hormone Treatment during pregnancy can be responsible
- Diethylstilbestrol (DES)→ Synthetic estrogen linked to reproductive and behavioral effects
- Medroxyprogesterone Acetate (MPA)→ Progestin used to prevent miscarriage, may affect fetal development
- Turner Syndrome (XO genotype)→ Typical hormone exposure until childhood; puberty onset may be disrupted
—>but study are flawed because case studies vary and confounding factors (medical conditions and parental expectations)
What are the effects of 5α-Reductase Deficiency, CAH and DES exposure on sexual orientation?
5α-Reductase Deficiency (XY Individuals)
- Raised as girls, sometimes married to men
- After puberty, most adopt male identity and prefer women
- Suggests androgens influence gender identity and sexual orientation
Congenital Adrenal Hyperplasia (CAH)
- Women with CAH show higher rates of bisexual/homosexual fantasies
- More same-sex attraction and experiences than non-CAH women
Diethylstilbestrol (DES) Exposure
- Masculinizing & defeminizing effects in animals
- In humans, prenatal DES exposure may slightly increase bisexual / homosexual activity (~25% vs. 15-20%)
- Majority (75%) of exposed women remain exclusively heterosexual
What is a biological correlates of homosexuality?
Biological correlates→ INAH-3 Size
- Smaller INAH-3 observed in homosexual vs. heterosexual men
- Unclear if genetic, hormonal, or behavioral factors cause differences
What is the sex difference in pain perception?
Pain perception→ increased pain sensitivity for women
- modulated by endogenous opioid system
- PET study using μ-opioid receptor–selective radiotracer
- Men exhibited greater opioid system activation in anterior thalamus, ventral basal ganglia and amygdala
For women→ dependent on menstrual cycles
- estrogen fluctuations influence pain perception
- high estrogen→ higher pain tolerance because more opioid activation
What is the difference between somatic and visceral pain?
Somatic-> well-localized, nocicepotrs, muscle, skin…)
Visceral-> vague and difuse, hollow organ, smooth muscle)
Somatic VS Visceral pain
- men tolerate more visceral and cutaneous pain better
- but higher muscle pain after exercise
What are the sex difference in olfaction?
Olfaction→ women have greater sensitivity to odors than men
- ex: women 1000x more sensitive to musk-like odors
- estrogen-dependent sensitivity→ emerges at puberty
- fMRI study→ Women showed up to eight times more activated voxels in specific brain regions (frontal and perisylvian areas)
Mood→ influenced by olfactory stimuli
- Δ4,16-androstadien-3-one→ immediately enhance mood for women if male tester
- some sex differences appear before puberty (girls more sensitive to amyl acetate)
How does women’s olfactory sensitivity fluctuates across the menstrual cycle and during pregnancy?
- Periovulatory women and early pregnancy→ Enhanced olfactory sensitivity
- Menstruating women and late pregnancy→ Reduced olfactory sensitivity
- Women with irregular menstrual cycles exhibit reduced olfactory sensitivity
What is the Kallmann Syndrome?
absence of olfactory bulb
- disrupts migration of GnRH from the nasal to the hypothalamus
- small testes and cannot detect odors
What are the sex difference in taste?
Taste
- women display greater sensitivity than men
- better at naming tastes and discriminating tastes (bitter more)
—>might be due to sex steroid hormone
- Differences arise after puberty
- Sensitivity is heightened during pregnancy and the follicular phase
- Sensitivity diminishes after menopause
What are the common solutions used to test taste?
- Sucrose (sweet)
- Citric acid (sour)
- Sodium chloride (salty)
- Quinine sulfate (bitter)
What are the sex difference in audition?
Audition→ women more sensitive
- noise tolerance level is lower for women (ex: 83 dB for men and 76 dB for women)
- study with baby→ girls maintain eye contact when reward was low-frequency tone VS boys performed the task better when reward was visual
What are the sex difference in vision?
Vision→ visual acuity better in men than women
- women tolerate higher levels of light intensity
- males rates have 20% more neuron son primary visual cortex than females
—>perinatal androgens inhibit cell death in the primary visual cortex of rats
