Describe the role of the anterior pituitary and hypothalamus in hormone release o Anterior pituitary o Hypothalamus glands Produces and secretes tropic hormones These influence the release of hormones from other Sends signals to the anterior pituitary to release inhibit hormone production and this continues on to other organs glands Summarize the role of testosterone in the sexual differentiation of the human body o Males o Females Principal male sex hormone and anabolic steroid aids the development of male reproductive tissues like the testis and prostate promotes secondary sexual characteristics like increased muscle bone mass and body hair growth essential for health well being and the prevention of osteoporosis Important for bone strength and development of lean muscle mass and strength Contributes to overall sense of well being and energy level Best known for women s sex drive libido i e sensitivity of woman s nipples and clitoris associated with sexual pleasure enhances sexual mood and experience Discuss sexual differentiation of the human brain and behavior o Brain NOT all or none mamawawa differences Slight variable statistical Differences in average b w males and females with plenty of overlap Usually no behavioral significance of differences Differences emerge in different parts of the brain at different times in different ways Parts no aromatization in some areas Times some differences not manifested until puberty Ways sometimes not through gonadal hormones o Different patterns of gene expression in brains of male and female mice before gonads are functional Cerebral cortex and cognition Men tend to have more white matter than women Women tend to have more neurons in language area of temporal lobe Men outperform women in some visuospatial tasks o Mental rotation of 3D objects o Throwing accuracy o Navigation or route finding Females outperform males in other visuospatial tasks o Route finding with landmarks o Memorization of location of objects o Rapid and fine manipulation of objects o Behavior Sexual dimorphisms Behavior or structure comes in 2 distinct classes male or female Heavily influenced by prenatal testosterone levels General average b w males and females with substantial overlap b w them Social interactions Play behavior Reaction to pain Language Cognition Emotionality Response to stress Moderately influenced by prenatal testosterone levels Examples of disease susceptibility between males and females Males o Dyslexia o Early onset schizophrenia o Stuttering o Autism o ADHD Females o Depression o Anxiety o Eating disorders Explain what intersex conditions teach us about human development o Intermediate or ambiguous sexual development o 1 100 kids born with some degree of sexual ambiguity o 1 2000 ambiguity is large enough to make gender assignment difficult Describe the effects of hormones anatomy and behavior in adulthood o Males o Women Minimum level of testosterone generally necessary for sexual activity interest and behavior Castration or chemical castration reduction in sexual o Rate and degree of loss varies o Still have adrenal testosterone Testosterone replacement rebound in sexual interest and activity In healthy men no correlation b w level of sex drive and testosterone levels Hypothalamus pituitary ovaries menstrual cycle Depends on 4 hormones o From anterior pituitary luteinizing hormone LH and follicle stimulating hormone FSH o From ovaries estrogen and progesterone More likely to initiate sexual behavior Find erotica more pleasant and arousing For a short term sexual relationship prefer more masculine looking men and men who seem athletic competitive and assertive and who did not describe self as having a nice personality o General Sexually dimorphic nucleus In mPOA Larger in males due to T E during critical period Size of male SDN is correlated with testosterone levels and aspects of sexual activity Human correlate is 3rd interstitial nucleus of anterior hypothalamus Other hypothalamic nuclei also larger in men than in women Discuss examples of the role of brain structures in mammalian sexual behavior o Sex chromosomes influence brain development independent of their effect on hormones become functional Different patterns of gene expression even before gonads o Estradiol plays active role in female program of brain development KO mice w o estradiol receptors don t show normal female brain development Compare human sexual orientation and gender identity o Both natural variations of human behavior o Essentially based on one s gender Organizing vs activating effects when do they occur Permanent or temporary Examples of each o When Organizational during sensitive periods of development activational any time in life o Organizational are permanent activational are temporary o Examples Organizational Activational Determines whether brain and body will develop male or female characteristics Menstrual cycle in women sexual excitement in men Pathway of synthesis of sex steroids Don t worry about of enzymatic steps just what is turned in to what and enzymes 5 alpha reductase and aromatase o All start with cholesterol base can be made into testosterone which can be made into DHT or estrogen depending on enzyme 5 alpha reductase converts testosterone to DHT 5 alpha aromatase converts testosterone to estradiol Negative feedback o Class of set point systems where feedback from changes in one direction elicit compensatory effects in the opposite direction For sexual development of body describe steps starting with SRY gene being turned on Understand what happens in females too o Y chromosome with SRY gene XY chromosomal male SRY gene triggers synthesis of SRY protein testes determining factor gonads medulla develop as testes o If no SRY gene protein ovaries develop usually in chromosomal female XX Rat studies Where is testosterone acting organizationally and when is it activational o Hormones and sexual behavior in rats Important distinction what happens during critical period of development constitutes organizational developmental effects of hormones General Untreated male masculinized and defeminized Untreated female feminized and demasculinized Castrated male feminized and demasculinized Treated female masculinized and defeminized Hormone given to adults that initiates a behavior is it acting For hormone to act activationally brain must be organized as activationally such Masculinization feminization demasculinization defeminization understand these
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