Chemical that is secreted by endocrine gland it is conveyed by the blood to other organs whose activity it influences They have more than one target and more than one action HORMONE Different classes o Steroids sex hormones o peptide STEROID HORMONES Androgens and estrogens are steroid hormones They contain four carbon rings derived from cholesterol Sex Hormones ANDROGENS TESTOSTERONE The male s Y chromosome includes the SRY Gene which causes those primitives gonads to develop into testes Both sexes have testosterone but more abundant in males Testes produce it Increase the growth of the testes causing them to produce more androgens Males testes produce more androgens than estrogens In 3 4 months of pregnancy sensitive period o High male character o Low female character Increases leads to sexual arousal in both males and females ESTROGENS ESTRADIOL The most prominent type of estrogen is estradiol Estrogen promote typically female features such as breast development In females the X chromosome will turn into ovaries which then will produce estrogen then the wolffian ducts will degenerate and the mullerian ducts will transfer into uterus and upper vagina Increase dendritic branches in hippocampus TESTOSTERONE ESTROGEN If both the testosterone and estrogen are low in an individual it might cause difficulties on their gender identity They may decrease pain and anxiety Play a role in increasing memory OXYTOCIN It s a hormone secreted by posterior pituitary gland It is important for pair bonding and social behavior It is released in orgasm in males and females It stimulates contraction at birth females Stimulate mammary glands to produce milk breast feeding in humans GENDER IDENTITY Only for humans Most people acquire a gender that matches their sexual appearance however Based on culture and the behaviors that is expected from that gender in that society hormones play a big role in this ORGANIZING AND ACTIVATING EFFECTS Organizing effects produce long lasting structural effects o The most prominent organizing effects occur during a sensitive stage of early development determining whether the body develops female or male anatomy Activating effects are more temporary o When a hormone increases some activity that lasts only while the hormone is present Activating effects occur at any time in life MULLERIAN AND WOLFFIAN DUCTS Mullerian ducts precursors to female internal structure Wolffian ducts precursors to male internal structure SRY GENE MIH SRY sex determining region on the Y chromosome causes primitive sex organs to develop into testes then testes will produce androgen hormones The wolffian ducts differentiate into seminal vesicles and the bas deferens MIH causes the degradation of the Mullerian ducts Mutation of SRY gene can cause the development of a genitals that have the characteristics of both male and female in males SEXUALLY DIMORPHIC NUCLEUS Area in anterior hypothalamus Is larger in males and contributes to control of male sexual behavior Causes male sex behavior In females it has a cyclical neuron firing which causes menstruation BARBIE VS GUN ALPHA FETOPROTEIN GENDER IDENTITY CAH INTERSEX It almost impossible to rule out the influence of environment on gender identity Immature mammals have a protein called alpha fetoprotein which is not present in adults Alpha fetoprotein in rodents binds with estradiol and prevents it from entering cells where it could produce masculinizing effects Is how we identify sexually and what we call ourselves People whose sexual development is intermediate The most common cause of intersexes is congenital adrenal hypothalamus meaning overdeveloping of the adrenal glands from birth Fairly common in female which leads to excessive secretion of testosterone resulting in external male characteristics They are referred to as intersex In the old day they would surgically remove parts of their body that looked like males however now the best thing to do is to wait for that individual to be old enough to decide which gender he she might want to be ANDROGEN INSENSITIVITY Certain individuals with an XY chromosome patterns have the genital appearance of a female These individuals produce normal amounts of androgens they lack the receptor that enables androgen to activate genes in a cell s nucleus They have internal testes and not uterus They do not menstruate HOMOSEXUALITY VS HETEROSEXUALITY ANTERIOR COMMISURE SCN INTERSTITIAL NUCLEUS 3 Gay man have been studied more than gay women Studies of monozygotic twins Identical shows that if one is homosexual the other twin has a 30 chance of being homosexual on the other hand if they are dizygotic there is 14 chance This also applies to females but lower probabilities There are hemisphere differences in straight individuals and gay individuals Heterosexual men o Right hemisphere is larger than heterosexual females and homosexual man o Right amygdala has more neural connections than heterosexual females and homosexual man o Interstital nucleus 3 located in Hypothalamus is larger than heterosexual females and homosexual men Homosexual than heterosexual men than heterosexual men o Anterior commissure is larger in homosexual men and heterosexual females o SCN Is larger and more elongated in homosexual men and heterosexual females Stress while pregnancy can lead to a homosexual son this can be due to the decreased levels of testosterone in the fetus There is probability that men who have older brothers might turn homosexual this can also be the result of an immune response of mom after giving birth to the second boy JAMES LANGE THEORY OF EMOTION It argues that we are actually afraid because we are running Their idea was that you get an appraisal of the situation a cognitive appraisal that occurs on the subconscious level immediately one gets the action and then one gets the emotion So really we re not running because we re afraid we re afraid because we re running EMOTION Limbic system plays a role in emotion Frontal area and temporal areas also important for emotion When an individual is happy or active more activity is seen on the left hemisphere When an individual is sad or disgusted more activity is seen on the right hemisphere INSULAR CORTEX STUDIES DONE ON EMOTION The feeling of disgust can be localized to insular cortex which is a primary taste cortex By far the most vigorous behavior all species including humans exhibit are attack and escape behaviors The phrase flight or flight comes from these behaviors