Gender Roles Midterm #2 Flashcards
Sexual differentiation
the process of development of the differences between males and females from an undifferentiated zygote.
Stages of sexual dimorphism
- Genetic stage
- inheritance of chromosomes (23 pairs) - Gonadal stage
- development of gonads (glands in which sex cells produced - Hormonal stage
- begins prenatally with secretions of androgens and estrogens by mother in womb
- child’s gonads cause further effects at puberty - Internal genitalia
- development of internal reproductive organs - External genitalia
- development of external reproductive organs
Reproductive system
- see a difference between male vs. female after 3 months
- Wolffian: male
- Mullerian: female
Male development
- Production of androgens
- Testes grow, produce more testosterone, stimulates further development
- Testes produce mullerian inhibiting substance
Female development
- Does not require any surge of hormones
- Wolffian system degenerates
- Mullerian system not inhibited
Sexual Dimorphism “Fairytale”
Assumes that: - biology always predicts gender - human beings come in 2 genders What happens when this goes wrong? - variations in sex chromosomes - variations related to hormones
Intersexuality
- Variations related to chromosomes & hormones (prenatal hormones not consistent with genetic development)
- 1 in 2000 births in US alone
Chromosomal Disorders
- Turner’s Syndrome (X0)
- Triple X Syndrome (XXX)
- Klinefelter Syndrome (XXY)
- XYY Syndrome (XYY)
Turner’s Syndrome
- Only one (X) chromosome on pair 23 (1 in 3000 live births)
- Prenatal develop begins fine; external genitals look female
- Mullerian system degenerates because no estrogen, ovaries do not function; no puberty/infertile
- Many take hormonal supplements and stay women
Triple X Syndrome
Extra “X” chromosome (female is XXX)
- 1 in 1000 females
Effects range from mild to severe
- normal intelligence or developmentally disabled
- cognitive problems common (speech, motor skills)
Also possible to have XXXX or XXXXX
- Very seriously developmentally disables and sterile
Klinefelter Syndrome
“XXY” chromosome
- 1 in 600 males
Male internal and external genitals
- BUT: small testes and cannot produce sperm
- Breasts may develop at puberty, feminine body shape, lack of male-type body hair
Risk for developmental disabilities & gender identity disorder
XYY Syndrome
1 in 1000 males
Other than taller height, no different looking than average male
- Very physically active, learning problems, lowered IQ, mental immaturity
- Genitalia, fertility etc. all normal
Potential issues with aggression?
- XYY men more likely to be in prison than XY men
-BUT perhaps due to developmental disabilities not aggression
- Crimes were no more likely to be violent
Prenatal Hormone Disorders
- Congenital adrenal hyperplasia (CAH)
- Androgen insensitivity syndrome
- Enzyme 5a Reductase Defiency
Congenital Adrenal Hyperplasia
Genetic-based malfunction of adrenal glands
- prenatally exposed to high levels of androgens
Males - earlier onset of puberty
Females - male-ish genital, “tomboys”, heterosexual women with female gender identity
Females often have surgery to reduce size of clitoris
- Controversial: may permanently damage clitoral nerves
Insensitivity Androgen Syndrome
XY (male), external genitalia ambiguous
Body cannot respond to androgens, body looks female-ish
- Usually detected because never menstruate or develop pubic hair during puberty
Infertility is common and 2nd sexual characteristics can be ambiguous
Most stay women despite learning they have XY chromosomes because identify as female and “act”/”look” female
Enzyme 5a Reductase Defiency
Prevents XY males from developing male external genitalia
Appear female at birth (ambiguous genitalia though) and usually identified as girls
During puberty, androgens lead to masculine characteristics
- Most make a fairly successful transition to male identity
- About 40% retain female identity
The Endocrine System
the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs.
Hormones
- Substances released from endocrine glands to circulate through blood stream
- Endocrine system = system with similar function, mechanisms, influence
- Some glands have different/multiple functions (pancreas - digestive enzymes AND hormones)
- Glands may secrete various hormones (steroid hormones produced by the reproductive organs)
Model of Steroid Hormones
Hypothalamus
- Controls many bodily functions (body temperature, thirst)
- Release hormones (specifically gonadotrophin releasing hormone (GnRH)
Model of Steroid Hormones I
Pituitary gland (lies just beneath the hypothalamus
- small (also looks like a chickpea)
Two parts:
- Anterior part s controlled by hypothalamus
- Posterior part is related to the nervous system
GnRH acts on anterior lobe of pituitary, causes it to produce and release:
1. Lutenizing hormone (LH)
2. Follicle stimulation hormone (FSH)
Gonadal Hormones
- 2 main classes are androgens and estrogens (produced by BOTH sexes)
- Men typically produce more androgens than estrogens (most common androgen is testosterone)
- Women typically produce more estrogens than androgens (significant individual variation)