Effects of Sex Hormones 1 Androgens INCLUDE Testosterone and DHT testosterone DHT androgen produced from testosterone produced through the action of the enzyme 5 alpha reductase the testosterone gets turned into DHT Testosterone Estrogen Testosterone can also get turned into estrogen by aromatase Defemenizations taking it away from natures default Brain and body are defemenized organizational effect of androgens that prevents the animal from displaying female sexual behavior in adulthood Androgens defemenization i Estrogen in the hypothalmus is what defemenizes the brain and makes it a male Yes estrogen helps the male pattern to develop Congenital adrenal hypoplasia CAH leads to homosexuality condition characterized by hypersecretion of androgens by the adrenal cortex In females it causes masculination of the external genitilia i Boys born with CAH develop normally ii Females have an enlarged clitoris and labia is partially fused together Females have an increased chance of becoming homosexual Excessive androgens affects development of the brain Androgens defemenization organizational vs Activational effects of the sex hormones Organizational developing breasts fat storage large hips changing permanent structure Activational periods 2 Distinguish organizational and activational Organizational permanent effects of sex steroids that are permanent within the brain body mass effect of a hormone on tissue differentiation and development Activity of sex hormones with receptors that change physical parts of the body e Activational immediate context can be reversed if hormone removed Signals from pituitary that control ovulation menstrual cycle occur later in life If you remove sex hormones the process stops spermogenesis periods 3 AIS Androgen Insensitivity Syndrome genotypically vs phenotypically AIS condition caused by congenital lack of functioning androgen receptors in a person with XY sex chromosomes causes the development of a female with testes but no internal sex organs The cause is a genetic mutation that prevents the formation of functioning androgen receptors the gene for the androgen receptor is located on the X chromosome XY without functional androgen receptors How does the body change Genotypic ex XY Mutations prevent formation of functional androgen receptors ie receptors for T and DHT T and DHT and Anti Mullerian hormones are secreted Anti Mullerian peptide secreted by fetal testes that inhibits the development of female internal sex organs Mullerian system embryonic precursors of the female internal sex organs T and DHT fail to have their normal organizational masculinizing effects Born with external female genetilia Gonads are undescended testes not ovaries At puberty develops a female body Know AIS Genetic males don t have functional androgen receptors how does that change the body Since males dont have the receptor they cant masculinize or create the male gentiala And since the body naturally makes females at puberty she will have have female parts however she will not have internal female organs because of the anti mullerian hormone 4 CAH congenital adrenal hyperplasia reverse of AIS XX High levels of androgens effects phenotypically how In females it causes masculination of the external genitilia shallow vigina CAH will affect sexual identity in the future females will be homosexual by being exposed to high levels of 5 Pheromones a chemical released by 1 animal that affects the behavior or physiology of another animal usually smelled or tasted and helps carry messages from animal to another VNO vomeronasal organ is a sensory organ that detects the presence of certain chemicals especially when a liquid is actively sniffed mediates the effects of some pheromones VNO is area that registers pheromonal stimuli VNO consists of a few hundred sensory receptors positioned near the top of the nasal sinus passages in most mammals including humans VNO sends information to the AOB accessory olfactory bulb AOB is a neural structure located in the MAIN olfactory bulb VNO AOB MOB main olfactory bulb Medial Nucleus of Amygdala POA Preoptic Area and Ventromedial Nucleus VMN of the Hypothalumus Hypothalamus detects the pheromone for reproduction These are the neural circuits for the effects of pheromones on sexual behavior Mammals pheromones regulate reproductive behavior In humans VNO is processed by PRIMARY OLFACTORY SYSTEM Know how humans are the exception to the VNO and pheromonal activity though there is some pheromonal activity in humans Processed by primary olfactory system VNO present but vestigial in humans However the main olfactory system still appears to register the effects of These differentially influence sex related behaviors in heterosexual men certain pheromones and women McClintock effect synchronized cycles in cohabitating women if not on birth control and not around men McClintock Effect Synchronized cycles in cohabitating women Women cant be on birth control Coordinate to the more dominate female A pheromone present in underarm sweat yuck appears to be key Extracts from the sweat of men advanced the onset of the next surge in LH Luteinizing hormone reduced anxiety and increased relaxation in women Two compounds in human sweat have differential effects on hetero men and hetero women These two show how humans feel about sex and potential mates Androstadienone AND AND will make females more aroused is an androgenic chemical shown to enhance positive affect and sexual arousal in women but to decrease positive affect in men Sex steroid hormone that produces pubic and axillary hair and also causes mood in women Estratetraene EST will make males more aroused is an estrogenic chemical which in men but not in women activates hypothalamic nuclei associated with sexual responding Maturation of female genitalia growth of breasts alterations in fat deposits growth of uterine lining inhibition of bone growth sex drive in women What Shows pheromonal activity and how men and women find mates Women who aren t on birth control initiate sex with their partners right around time of ovulation Estradiol a type of estrogen secreted as the follicle matures levels are the highest during ovulation Pregnancy is most likely following sexual activity What Causes Homosexuality Know genetic contribution Monozygotic versus dizygotic There is Genetic contribution but it does NOT determine sexual orientation Maternal stress however might play a role in decreasing the effectiveness of prenatal