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Bio Psych Exam3 Pt4
Ch 11. Sex & Hormones
Question | Answer |
---|---|
What are hormones? | Chemical messengers that are released into the bloodstream; their messages are widespread (unlike NTs); sex hormones are a type. |
What are sex hormones? What produces them? | There are three main categories: Estrogens (ie Estradiol), Androgens (ie Testosterone), and Progestins (i.e. Progesterone); they are produced by the Gonads (ovaries or testes) and Adrenal Glands |
How do hormones exert their effects? | They exert their effects by binding to (metabotropic) receptors, activating proteins and through gene expression |
What are sex differences in regards to hormones? | The relative amounts of Estrogens and Androgens differ between sexes (males have more Androgens, females more Estrogens); also the timing of release is different (women's are released cyclicly, while men's are released steadily) |
What are Ovaries? | Gonads develop into Ovaries for females; they produce ova (eggs), which have an X sex chromosome |
What are Testes? | Gonads develop into Testes for males; they produce sperm, half of which have an X sex chromosome and half of which have a Y |
What determines hormone production (and therefore sexual development)? | The 23rd (final) pair of chromosomes (XX or XY) determines hormone production; the presence of absence of a Y chromosome |
What are the types of effects that sex hormones have on us? | They have both Organizing and Activating effects |
What do Organizing and Activating refer to? | The different types of effects that sex hormones have on us |
What are Organizing effects? | Long-lasting effects of a hormone that are present during a sensitive period in development; occur from conception to sexual maturity; they are changes in the brain and body that distinguish females from males; differentiation begins at fertilization |
What are Activating effects? | Temporary effects of a hormone, which occurs when that hormone is present; after sexual differentiation occurs; trigger behaviors (often related to reproduction); specific behavior depends on organizing effects; influence outside of sensitive periods |
What is the default pattern of development? | To develop as female |
What are the Gonads? | Sex gland that produces sex hormones; Ovaries (female) or Testes (male) |
Describe the development process and timeframe of the Gonads. | Development of Gonads begins 6 weeks after conception; presence or absence of SRY protein (produced by Sex Determining Region on Y chromosome) causes Gonads to develop one way or the other |
Describe the development of Ovaries. | Because there is no Y chromosome present in females, there is no SRY protein; gonads develop as Ovaries |
Describe the development of Testes. | Y chromosome contains a Sex Determining Region; produces SRY protein; SRY protein causes gonads to develop as Testes |
Describe the development process and timeframe for External Genitalia. | Begins 8 weeks after conception (3rd month); begins with the same primitive structures; if testosterone is present, male structures develop; if testosterone is absent, female structures develop |
What determines whether Testosterone is present for the development of Genitalia? | The presence of Testosterone is determined by the previously developed Gonads- if Testes developed, Testosterone is present. |
Describe the development process and timeframe for Internal Sex Organs. | Begins 8 weeks after conception (3rd month); everyone is born with two sets of primitive sex organs (Wolffian & Mullerian); in males, Testosterone promotes the Wolffian system while MIH degenerates the Mullerian; default pattern is to develop as female |
What is the Wolffian System? | One of two sets of primitive internal sex organs present at birth; it is promoted by Testosterone (released by the previously developed Testes in males) |
What is the Mullerian System? | One of two sets of primitive internal sex organs present at birth; default is to further develop the Mullerian system, but MIH (released by the previously developed Testes in males) degenerates the Mullerian system |
Describe the development process for Male Internal Sex Organs. | Both the Wolffian and Mullerian system are present at birth; default to further develop Mullerian system, but in males the presence of MIH (released by the previously developed Testes) degenerates Mullerian system; Testosterone promotes Wolffian system |
Describe the development process for Female Internal Sex Organs. | Both the Wolffian and Mullerian system are present at birth; default to further develop Mullerian system. |
What are Primary Sex Characteristics? | Sexual dimorphisms that are present at birth (Gonads, Internal & External Sex Organs); they are Organizing Effects |
What are Secondary Sex Characteristics? | There is a surge in sex hormones during puberty that causes growth spurt, body dimorphisms & the onset of fertility; they are Organizing Effects |
What happens if you disrupt sex hormones during a sensitive period? | Influences Organizing Effects. |
What happens if you disrupt sex hormones outside of a sensitive period? | Influences Activating Effects. |
What could happen to a female if her Testosterone levels were increased? | Can cause masculinization of the brain, external genitalia and behavior |
What are certain things that could have feminizing effects on a Male? | Estradiol (an Estrogen) exposure; certain drugs (like alcohol & marijuana) |
Describe Androgen Insensitivity Syndrome. | Individuals with an XY chromosome pattern (genetically male) have the genital appearance and expresses characteristics of a female; internally, they have underdeveloped sexual organs of both sexes; see case of Anne S. |
What is Androgen Insensitivity Syndrome caused by? | Abnormal Androgen Receptors; see case of Anne S. |
How do Abnormal Androgen Receptors influence development in Androgen Insensitivity Syndrome? | Testosterone present, but cant interact w receptors; its needed for masculinization (or Wolffian system & male external genitalia dont develop, brain & behavior develop as female); MIH is present, so Mullerian doesn't fully develop; see case of Anne S. |
Describe the case of Anne S. | 26 y.o. housewife presenting with lack of menstruation & pain during sex; exam reveals normal female genitalia but abnormal internal sex organs; DNA shows XY (male) genotype; diagnosis: Androgen Insensitivity Syndrome |
Describe Congenital Adrenal Hyperplasia (CAH). | Most common disorder of sexual development; results in masculinizing effects on a female, XX fetus; ambiguous external organs, behavior (such as toy preferences & play) are altered; increased interest in bi-/homo- sexuality; see case of Elaine |
What is the cause of Congenital Adrenal Hyperplasia (CAH)? | Adrenal Gland functions abnormally, produces excessive androgen levels which cause the masculinizing effects; see case of Elaine |
Describe the case of Elaine. | Female born w masculinized external genitalia; excessive levels of androgens for XX female; parents chose to "normalize" development (surgery for genitalia, hormones to decrease androgens, estrogens to help with secondary sex characteristics); CAH |
Describe the case of John->Joan. | Botched circumcision at 8 mo; expert recommended castration, surgery, and estrogen at puberty; reported outcome- female-typical development; reality- persistently resisted feminization; truth revealed at 14 y.o. |
What does the case of John->Joan highlight? | The Nature/Nurture Dynamic of Sexual Development; XY Genotype + Prenatal Androgen Exposure VS. Social Learning |
What caused the outcome of the John-Joan case? | It's not just about external genitalia and/or socialization; early organizing effects and prenatal androgen exposure are important! |
What are some sex differences in the brain (Female)? | Females have more communication between hemispheres; high levels of Estrogen may be linked with verbal fluency; have better fine motor control |
What are some sex differences in the brain (Male)? | Male brain has a larger volume; have better spatial relations, mental rotation (which is linked to Testosterone) |
How do hormones affect the brain? | Hormones influence cell growth & death rates; # of neurons & synapses |
What two parts of the Hypothalamus that highlight sex differences? | Sexually Dimorphic Nucleus & Ventromedial Nucleus; some of the clearest biological sex differences |
What is the Sexually Dimorphic Nucleus and where is it located? | Part of the Hypothalamus that is linked to male sexual behavior (like mounting); if damaged, this behavior is decreased; much larger (2X) in males than in females; linked to Testosterone |
What is the Ventromedial Nucleus and where is it located? | Part of the Hypothalamus that is linked to female sexual behavior (like arching); If damaged, this behavior decreases; larger in females |
How do the Activating Effects of Sex Hormones influence the brain? How long does it take? | Changes the brain's response to different experiences; primarily by influencing the hypothalamus; 15-30 minutes |
What is Estrogen? It's activating effects? | Category of sex hormone (including estradiol) that are more abundant in females; may be linked with verbal fluency; activating effects include sensitizing sensory nerves, alter pain sensitivity and increase sexual arousal and sensitivity |
What are Testosterone's activating effects? | Can alter dopamine levels; increase sexual arousal and sensitivity |
Describe Testosterone levels in married men; what does this mean? | Lower levels of Testosterone in married men; levels are linked with marriage & infidelity (low levels: marriage & cohabitation/ high levels: infidelity, divorce, single) |
Describe the effects of castration on sex offenders? What does this illustrate? | Illustrates the activating effects of sex hormones in men; effects of castration include altered sexual interest & behavior, less body hair, and fat deposits on the hips and chest |
Describe the Periovulatory period for females. What does this show? | Shows the activating effects of sex hormones; estrogen levels peak; up interest in sexual activity; preference for highly masculine faces |
Why are men more likely to seek sex with multiple partners? What is this perspective called? | Evolutionary perspective says... Genetic fitness- want to spread their genes! They can father many children, while women can only have one pregnancy per 9 months! |
What are the two strategies for genetic fitness? Which do men choose and why? Women? | Loyalty and Deadbeat Dad (as many children as possible); Second option is unavailable for females (caregiving linked to oxytocin, they are the pregnant ones) |
Describe the evolutionary perspective for men's dating choices and habits. | Men focus more intensely on physical attributes (such as facial symmetry, hip to waist ration, and youth) which are predictors of genetic fitness & reproductive capacity. |
Describe the evolutionary perspective for women's dating choices and habits. | Women tend to be more selective; parental investment differences; pregnancy & childcare limit resources; seek provider, physical protection, and promise as a parent; caution during courtship. |
Why do men react more intensely to infidelity than women do? | Because they have a lot invested in their own genes; men are not certain about which offspring they father while women know if they are pregnant its theirs; crossculturally, infidelity is never more appropriate for women (either same or less) |
Describe the concordance rates for sexual orientation. | If a male twin is homosexual, an identical male twin is also homosexual about 50% of the time; a fraternal male twin is also homosexual about 20% of the time; suggests a genetic component to sexuality. |
What are non-genetic factors for sexual orientation? | Prenatal hormone levels; maternal stress; number of biological older brothers (3% increase in likelihood a male will be homosexual for each older brother- bc moms immune system begins to suppress androgen levels with each male pregnancy) |
What is the Interstitial Nucleus 3 of the Anterior Hypothalamus (INAH3)? | correlates with sexual preference/orientation; denser set of cell bodies in heterosexual man than in a homosexual man or heterosexual female; lesioning this region causes loss of sexual interest, not a change in preference |
What is the Bed Nucleus of the Stria Terminalis (BNST)? | size correlates with sexual/gender identity, not sexual preference; Stria Terminalis links the thalamus, hypothalamus & amygdala |
What are Adrenal Glands? | Endocrine glands that sit on top of the kidneys and produce hormones, including androgens |
What is Mullerian Inhibiting Hormone (MIH)? | A defeminizing hormone that comes from the testes; aids in degeneration of the internal Mullerian structures |
What are Masculinizing Effects? | Promotes male development; ie testosterone aids in growth of Wolffian system; testosterone is key in masculinization |
What are Defeminizing Effects? | Works against female development; ie MIH degerates Mullerian structures; MIH is key for defeminiziation |
What is SRY? | SRY is a protein produced by the Sex Determining Region of the Y chromosome (which is only present in males); SRY protein causes gonads to develop as testes; bc females have no SRY protein, their gonads develop as ovaries |
What is Gender Identity? What structure is it tied with? | The sex with which a person identifies; biologically tied to Bed Nucleus of the Stria Terminalis (BNST) |
What structure is Sexual Preference tied to? | INAH3 (Interstitial Nucleus 3 of the Anterior Hypothalamus) |