3-10-10 Reproductive Physiology-Hormones-color

3-10-10 Reproductive Physiology-Hormones-color - Clicker...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Clicker Question From observing the offspring of a black man and a white woman in the 18th century, Maupertuis realized that _________. A) B) C) C) D) E) RED CARPET SOCIETY & CU IMAGE 161 Things Every Cornellian Should Do: #113: Host a prefrosh To Join, Come to a Host Training: March 8-11,15 and 16! and 16! 5:30-6 or 6:30-7 RPCC Room 101 Note: Only Students Living in Dorms/ Program Houses Can Host the hereditary information came primarily from the mother the hereditary information came primarily from the father the father and mother contribute equally to the inheritance of the offspring each sperm contains a miniature version of the offspring and thus should not be wasted the egg contains a miniature version of the offspring, but only if the offspring is a girl Rising Waters: Global Warming and the Fate of the Pacific Islands Warren Hall B45 Wednesday March 10th 4:45pm- 6pm Film Screening as part of our continuing Environmental Justice Film and Speakers Series Hosted by Roots and Shoots contact Ariana Wermer-Colan at [email protected] Prelim 1/Makeup Luck Favors a Prepared Mind 1 Luck Favors a Prepared Mind Where are we? Last Last time I covered… Reproductive Reproductive biology of men and women. http://www.teenwire.com/ Today I will cover… What What makes one a man, a woman, or an intersexual? (The definition of sex, like the definition of life, is not as clear as one may expect.) Environmental Environmental estrogens. Contraception. Contraception. There Are Gradations between the Extremes Plato’s Plato’s Symposium and Soulmates In In the old days, people had spherical bodies, with two faces, two sets of privates, four arms, and four legs. There were males, females, and hermaphrodites. The people became so powerful that Zeus decided to chop them in half. After After chopping the people in half, Zeus pulled the skin tight and stitched it up to form the belly button. Ever since that time, people run around saying they are looking for their other half. Plato's Symposium What Is a Male and What is a Female? The Historical Approach The The historical approach allows one to see, in the words of George Palade (1963), “that Video Hedwig and the Angry Inch recent findings and present concepts are only the last approximation in a long series of similar attempts which, of course, is not ended.” 2 Before the Discovery of Sex Chromosomes, it was Relatively Easy to Tell the Boys from the Girls The Male and Female Phenotypes were Distinguished by the Genitalia Prince Albert and Queen Victoria Males Males had a penis; females had a vagina. Expectant parents are typically asked, “Are you hoping for a boy or a girl?“ …and they typically answer, "It doesn't matter, as long as it's healthy.“ Nursery for Girl or Boy But what if the baby is neither a boy nor a girl? 3 Ambiguous Genitalia: Boy or Girl? Ambiguous Genitalia: Boy or Girl? newborns.stanford.edu newborns.stanford.edu Ambiguous Genitalia: Boy or Girl? Reinier de Graaf Observed an Intersexual in 1670 Reinier De Graaf (1670): A. The clitoris looks like a penis. B. The glans of the clitoris. C. The labia. D. Protuberances that look somewhat like testicles. newborns.stanford.edu Male or Female—A False Dichotomy? Levi Suydam • In 1843, before women had the right to vote, Levi Suydam, a 23-year-old resident of Salisbury, CT, asked to be allowed to vote as a Whig in the local election. The Tory party objected because Levi was more female than male. because Levi was "more female than male." • Dr. William Barry, a physician examined Levi and upon finding a penis and testicles, declared Levi was a male and could vote. The Whigs won the election by one vote. • Levi did not tell Dr. Barry that he/she menstruated regularly and had a vaginal opening. Was Levi a man or a woman? • Today, which legal rights are guaranteed only to legally-defined men or women? Sex can be Assigned by the Parents or Reassigned by the Individual with the Help of Surgery 4 George/Christine Jorgensen Richard Raskind/Renee Richards James/Jan Morris Walter/Wendy Carlos www.wendycarlos.com Barry/Caroline Cossey So How is One’s Sex Determined? 5 Understanding the Biology of Sex Determination Helps Us to Understand Our Sexual Selves and to be Tolerant of Others Chromosomal Sex You You probably learned that humans have 46 chromosomes arranged in 23 pairs. One pair, composed of the X and Y chromosomes, and determines whether one is male or female. The The mother, with her diploid (XX) typically produces germ cells, typically produces haploid eggs that are all X and the father, with his diploid (XY) germ cells, typically typically produces haploid sperm that are either X or Y. A zygote with XX chromosomes will zygote XX typically typically develop into a female, and XY one with XY chromosomes will typically typically develop into a male. E. B. Wilson and Nettie Stevens The Chromosomal Basis of Sex E. E. B. Wilson and Nettie Stevens noticed that in many animals there were two accessory chromosomes that they called accessory chromosomes that did not look like each other the way other chromosomes in a homologous pair looked like each other. The accessory chromosomes were later called X and Y chromosomes. The testicular The testicular cells that gave rise to sperm chromosomes had both the X and Y chromosomes. The ovarian The ovarian cells that gave rise to eggs had two X chromosomes. Wilson Wilson and Stevens concluded that the presence presence of a Y chromosome determined maleness and the absence of a Y absence chromosome determined femaleness. Sex Sex is Determined by Chromosomes This This was the first evidence first Chromosomal Male and Chromosomal Female that one of the hereditary traits that determine our uniqueness was carried by chromosomes chromosomes. Zygotes Zygotes that get a Y chromosome chromosome from the sperm sperm become chromosomally become chromosomally male while the zygotes that get an X chromosome chromosome from the sperm sperm become chromosomally chromosomally female. Thus the sperm sperm determines determines the chromosomal chromosomal sex of the zygote. 6 The Unequal Distribution of Chromosomes (Non(NonDisjunction) During Anaphase II of Meiosis ReReenforces the Role of the Y Chromosome in the Determination of Sex Individuals Individuals with one Y chromosome (XY, XXY, XXXY or XXXXY) XXY or XXXXY develop into (mostly) males. Individuals with no chromosome Individuals with no Y chromosome (XO, XX or XXX) develop into XX XXX (mostly) females. This This indicates that something on the Y chromosome causes an chromosome individual to develop into a male. Klinefelter Klinefelter Syndrome (XXY) occurs in 1/750 males and Turner Syndrome (XO) occurs in 1/2500 females. Klinefelter (XXY) and Turner (XO) Syndrome Klinefelter Syndrome klinefeltersyndrome.org www.turnersyndrome.org Chromosomal Sex chromosomes typically develop males into males and embryos with XX embryos with XX chromosomes chromosomes typically develop females into females. Embryos Embryos with XY XY But But the phenotypic not sex is not always correlated with the chromosomal sex. CisCis-Sexuals and Trans-Sexuals TransWe We could make two columns of characteristics: typical one that defines a typical male and another that typical defines a typical female. Having all of the Havin characteristics that are in one column and none of the characteristics that are in the other column cis results in a cis-sexual. Having Having characteristics from both columns makes trans one a trans-sexual, also known as an intersexual intersexual. Male Female testes ovaries penis vagina XY XX high androgens androgens high estrogens estrogens androgen sensitivity Chromosomal Sex Does Not Always Define Phenotypic Sex There There is a small possibility that a person can have two X chromosomes (XX) and be male in all other regards. If certain segments of the If certain segments of the Y chromosome chromosome are broken off and transferred to another chromosome or transferred to the X chromosome during meiosis, the phenotypic phenotypic sex can differ from the chromosomal sex. This This means that sex is determined by more than just the type of sex chromosome an individual has. 7 The Phenotype Depends, in Part, on the Genotype The phenotype The phenotype is the outward appearance of a trait (e.g. male or female). female). The genotype The genotype is the combination of heritable materials (alleles made of DNA) that have the potential to code for the trait in question. How is Genetic Diversity Generated? DNA)— DNA)—a mutation produces a new allele. An allele is a allele variation of a gene. Independent Independent Assortment is th the random mixing of the th maternallymaternally-derived and paternallypaternally-derived chromosomes in an individual. Recombination Recombination (crossing over during meiosis) produces different combinations of the alleles of various genes (e.g. hair and eye color)—it is like shuffling color)— cards. Mutation (nucleotide Mutation (nucleotide change in As As a Result of Mutations, Homologous Chromosomes Carry Different Versions (Alleles) of Genes Meiosis Can Introduce Variability (Individuality) in All Traits Gametes like those that created you. Gametes unlike those that created you. The independent orientation of the pairs of independent homologous chromosomes during metaphase I of meiosis makes it possible for the gametes you produce to differ from the gametes that created you. Your Gametes are not Like your Mother’s nor your Father’s Gametes As As a consequence of independent orientation, the total number of Children by Kahlil Gibran They come through you but not from you, And though they are with you, yet they belong not to you. You may give them your love but not your You may give them your love but not your thoughts. thoughts. For they have their own thoughts. Your children are not your children. They are the sons and daughters of Life's longing for itself. chromosomal chromosomal combinations that can be combinations that can be created created in the gametes is 2n, where n is the haploid haploid number of chromosomes. In In humans, where n = 23, there are 223 or 8,388,608 different possible gametes based on independent orientations alone. 8 Crossing Over or Recombination Further Increases Genetic Variability Chromosomal Sex vs. Gonadal Sex Up Up until 6-7 weeks in the womb, 6the gonadal sex of the embryo is gonadal undetermined undetermined and the testes and ovaries exist as undifferentiated ovaries exist as undifferentiated gonads gonads. There There is a “maleness factor” on chromosome typically on the Y chromosome that determines whether the gonads will differentiate into testes ovaries testes or ovaries and become gonadally gonadally male or female. SixSix-Seven Weeks: The Undifferentiated Reproductive System The The developing embryo (XX or XY) contains undifferentiated undifferentiated gonads and has the potential to potential be either male or female. It It also contains two systems of genital genital ducts. The Mullerian The Mullerian ducts can differentiate into the Fallopian tubes, uterus, and the upper vagina (=femaleness). The Wolffian The Wolffian ducts can differentiate into the epididymis, epididymis, vas deferens and seminal vesicles (=maleness). Development Development of the Female Reproductive System In In the absence of the absence maleness maleness factor on the Y chromosome chromosome, the gonads stay in place and differentiate into ovaries. Th The Wolffian ducts degenerate. The Mullerian The Mullerian ducts continue to differentiate into differentiate The The female developmental program does not require any embryonic hormones, just the absence of male hormones. Fallopian tubes, uterus and the vagina. Development of the Male Reproductive System gonads differentiate into testes, which produce testosterone. testosterone The The testosterone prevents the disintegration of the Wolffian Wolffian ducts and allows them to epididymis, differentiate into the epididymis, In In the presence of the maleness presence maleness factor on the Y chromosome, the chromosome Development Development of Genital Ducts in Gonadal Males and Females vas deferens and seminal vesicles. The The testes also produce a hormone known as the Mullerian inhibiting Mullerian factor (MIF), which causes the destruction destruction of the Mullerian ducts. 9 Sex Hormones, including Androgens, Progestins and Estrogens as well as other steroid hormones, hormones, including Aldosterone and Cortisol are Synthesized from Cholesterol arbl.cvmbs.colostate.edu/hbooks/pat hphys/endocrine/basics/steroidogen esis.gif Intracellular Location of Enzymes Phenotypic Sex: The Fate of the Undifferentiated Phallus Before Before the testes start producing testosterone and other androgens, all embryos androgens look female from the outside. They have a vulva-like vulvaopening, labia-like folds and a opening labia like folds and small small undifferentiated phallus. In In the 7th -12th week, androgens androgens cause the undifferentiated phallus to become the penis in a male. penis in Without Without androgens, the undifferentiated phallus becomes the clitoris in a clitoris female. External Genitalia: Labia Majora and Scrotum The labioscrotal swelling becomes the labia majora, the labioscrotal labia entrance to the vagina and the exit for the urethra in a female. In males, it fuses to form the scrotum and scrotum consequently, a new urethra exit must be formed. 10 External Genitalia 12th Week The urethra in urethra the female naturally exits through the labia However labia. However, in males, when the labioscrotal labioscrotal swelling fuses fuses to form a scrotum scrotum, a new urethra urethra is formed from the bladder bladder to the tip of the penis. penis The Testes Descend Into the Scrotum (2(2-9 Months) The The testes are formed near the kidneys. In In order to produce viable sperm at the requisite requisite temperature (94 °F), the testes must descend from the abdominal cavity (98.6 °F) to the scrotum. The The testes are initially held in place by the suspensory suspensory ligament, which holds them near the kidney and the gubernaculum, which pulls them gubernaculum, toward the scrotum. The Testes Descend Into the Scrotum (2(2-9 Months) The The SRY Gene is the Maleness Factor that Causes Male Development In In the 1990s it was discovered that in 0.005% of babies, the males had XX chromosomes and the females had XY chromosomes. The chromosome in the XY The Y chromosome in the XY females females had a piece missing and the X chromosome in the XX males had an extra piece. The The gene on the region of the chromosome that contained the maleness factor was named sry, maleness sry exwhich stands for Sex-determining Region on the Y chromosome. chromosome. Testosterone weakens Testosterone weakens the suspensory ligament suspensory which which facilitates the downward movement. The The testes produce insulin-like-hormone-3, which insulin-like-hormonestrengthens the gubernaculum which causes it to gubernaculum pull the testes to the scrotum. How do we know that the sry gene determines the sex of the baby? Female Female mice do not have the sry gene. Male Male mice do have the sry gene. It is turned on in the gonad for only a couple of days. If If the sry gene is damaged, XY mice become females. If If the sry gene is put into XX mice, they become males. The sry Gene is a Master Switch that Triggers Maleness sry sry seems to be the master master switch that triggers the events that convert the embryo into a male male. Without Without the sry gene, the sry embryo develops into a female, indicating that femaleness is the "default" program. This This makes sense since the the Male embryo is developing in a woman’s body, flooded with estrogens. Female 11 How does the sry gene cause the gonads to become testes? Sry seems to turn on or off several genes that result in the differentiation of testes. Cross-overs between the two pathways can occur at any level. Various Definitions of Sex for Males and Females • • • • Chromosomal Sex Genetic Sex Gonadal Sex Phenotypic Sex Sex 1° characteristics 2° characteristics • Metabolic Sex XY or XX sry or no sry testes or ovaries penis or vulva ejaculate or ovulate androgens or estrogens Steroid Hormones and Puberty The The ovaries and testes are endocrine glands endocrine glands that produce three classes of steroid hormones: estrogens progestins estrogens, progestins and androgens and androgens. These These hormones induce puberty, puberty which is the time an individual becomes capable of capable reproducing. Typical Typical females have high ratios of estrogens to androgens. Typical Typical males have high ratios of androgens to estrogens. The secondary sexual characteristics appear during puberty. Puberty: Androgens Cause Secondary Androgens Secondary Sex Characteristics to Develop in Males Males Increased Increased bone growth, muscle appetite and muscle mass, which results in broad shoulders and chests broad shoulders and chests A prominent Adam's apple prominent and deeper voice due to lengthened larynx Pubic, Pubic, facial, chest and abdominal hair; baldness Exaggeration Exaggeration of preexisting patterns of aggression Puberty Estrogens Puberty: Estrogens and Other Hormones Cause Secondary Sex Characteristics to Secondary Develop in Females Females Enlarged Enlarged breasts with functional mammary glands Menstrual cycle Menstrual cycle Pubic Pubic and underarm hair Subcutaneous Subcutaneous fat Wider Wider hips than shoulders Smooth Smooth skin texture 12 Hormones and Sex-Specific Behavior SexSinging Singing is a secondary sex characteristic in canaries. The The males sing and the females do not. Cornellian Cornellian Sam Leonard testosterone (1939) injected testosterone into into female canaries and they started to sing like males. Perhaps, Perhaps, in general, sex hormones regulate “sex“sexspecific behaviors” in humans, but the evidence is not clear. Could Taking Male Hormones Make Males More “Manly?” Anabolic Steroids Corticosteroids, Corticosteroids, like cortisol are catabolic steroids catabolic that cause the breakdown of muscle tissue. breakdown Androgens Androgens are anabolic steroids that stimulate anabolic appetite and induce the build-up of muscle tissue buildand increase the ability to hit home runs and increase the ability to hit home runs. Anabolic Anabolic steroids at excessive levels will be converted converted to estrogen, thus blurring some distinctions between men and women. Excessive levels of anabolic steroids cause sexual side sexual effects, including men developing breasts and a lower sperm count. Women using anabolic steroids will develop body hair and a deeper voice. The Senate Has an Interest in the Illegal Use of Anabolic Steroids by Athletes Alex Rodriguez Used Steroids www.drugfreesport.com “My mistake came because I was immature and I was stupid. It wasn't because of the Rangers or anything to do with Texas. I blame myself. For a week here, I have been looking for people to blame, and I keep looking at myself at the end of the day." 13 Mark McGwire: “I Used Steroids.” “The sad thing, as we’ve seen from baseball and Olympic scandals, is that steroids are as good steroids are as good as as advertized….They are wrong to use because they lead to an unlevel playing field.” Steve Tasker did not use steroids. Cell Biologist Werner Franke Courageously Exposed the East German Doping Machine Organotherapy: Organotherapy: Using Organ Extracts for Treatment "We have a positive cure for homosexuality," exclaimed Professor Leopold Ruzicka, a Ruzicka, Swiss organic chemist who lectured at the University of Chicago this summer.” Time Magazine September 2, 1935 Organotherapy: Organotherapy: Using Organ Extracts for Treatment “To produce one ounce of natural testosterone would require the castration of some 1,000,000 sturdy men. German and Swiss chemical laboratories are already prepared, said Dr. [Leopold] Ruzicka last week, to manufacture from [the lanolin in] sheep's wool all the testosterone the world needs to cure homosexuals, revitalize old men.” Organotherapy When testosterone injections did not work as a “cure for homosexuality homosexuality”, physicians turned to estrogen injections, which also did not work. This treatment, however, may have changed the world. Time Magazine, 1935 14 Alan Turing, Homosexuality and Estrogen and worked on the theory of pattern formation in organisms, was arrested for being a homosexual. He was tried in homosexual England as a homosexual on March 31, 1952, 1952, his defense being that he saw nothing wrong with his actions. He was prison found guilty and given the option of prison or estrogen injections. He chose the latter, developed breasts, and continued his work in biology on the genesis of form. He committed suicide in 1954, using the cytochrome oxidase inhibitor, cyanide. cyanide Alan Turing, who invented the computer The Production of Sex Steroids in Males and Females is Regulated by the Hypothalamus and Anterior Pituitary The hypothalamus synthesizes The hypothalamus synthesizes and secretes “releasing hormones” that travel though a portal vein to the anterior pituitary. anterior The stimulated anterior pituitary synthesizes anterior and secretes Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). LH LH stimulates the production of sex the production of sex hormones by the ovaries and testes. FSH FSH stimulates the production of eggs and the production of eggs and sperm. sperm. Control of Sex Hormones Post Pubescent Hormone Levels in Males are Constant 15 In Females, Post-Pubescent PostHormonal Levels Cycle FSH stimulates FSH stimulates the growth of the follicle. As As the follicle grows in the ovary, it secretes more and more estrogen. estro When When the follicle is mature, the estrogen estrogen level peaks. High estrogen levels of estrogen stimulate the hypothalamus to secrete more releasing hormones which causes the anterior pituitary to secrete massive amounts of FSH FSH and LH. LH In In Females, Post-Pubescent PostHormonal Levels Cycle The The high levels of FSH and LH FSH LH induce ovulation. High High levels of LH also induce LH also the corpus luteum to secrete co to sec estrogen and progesterone. and progesterone The The high levels of estrogen estrogen and progesterone cause the progesterone cause pituitary to stop secreting FSH FSH and LH. LH This This results in a decrease in the production of estrogen and progesterone. In Females, Post-Pubescent PostHormonal Levels Cycle Pregnancy stops the cycle stops because the secretion of hCG by hCG the chorion causes a continued secretion of progesterone and progesterone estrogen by the corpus luteum estrogen by the corpus luteum. The high levels of progesterone progesterone and estrogen inhibit and estrogen inhibit ovulation and prevents the sloughing off of the endometrium (menstruation). Birth control pills release high enough levels of estrogens and progestins to prevent ovulation. Menstruation The Story of Menstruation Video Museum of Menstuation and Women's Health If Men Could Menstruate by Gloria Steinem The Male-Female Continuum MaleMales Males and females are not necessarily qualitative opposites determined by having XY or XX chromosomes. While While the distinction between males and females is, in general, a reasonable biological distinction, there is a malemalefemale continuum that makes sex identity, in a small portion of the population, a somewhat quantitative and continuous characteristic. gendertalk ukia.co.uk isna.org intersexsupport intersexinitiative.org Female Individuality 16 Male Individuality Circumcision (Health and Religious Freedom): A Decision to be Made by an Individual, a Parent, or Government? MA Senate Bill S.1777 www.intactamerica.org www.mgmbill.org www.cdc.gov A Phallus—Intermediate Between a Phallus— Penis and a Clitoris External Genitalia— External Genitalia—Intermediate between a Scrotum and a Vulva Intersex (TransIntersex (Trans-sexuals): Disorder or Condition? the sex chromosomes, the gonads, the genitalia and the secondary sexual characters. While While the majority of babies born are girls or boys, a small are percentage percentage of people are born intersexuals. Some Some people label intersexuality a disorder and it is called in the DSM IV a disorder of sexual disorder development (SDS). Others Others consider intersexuality an condition individual condition equal in status to male and female. Intersexuality: Intersexuality: sry Gene Phenotypic Phenotypic males with XX chromosomes may have resulted from a translocation of the sry sry gene to one of the X chromosomes chromosomes. Phenotypic women with XY Phenotypic women with XY chromosomes chromosomes may have a mutant mutant form of sry. Phenotypic Phenotypic women with XY chromosomes may have the sry sry gene on the Y chromosome but a mutation mutation in another gene that makes them insensitive to insensitive androgens or produce less or produce weaker androgens . Intersex refers Intersex refers to mismatches in XY ais aissg 17 Intersexuality: Complete Androgen Insensitivity Syndrome (CAIS) Males Males and females usually have at least one X chromosome that contains androgen a gene that codes for an androgen receptor that makes their body sensitive to androgens. If this gene has mutation that leads If this gene has a mutation that leads to complete to complete androgen insensitivity, a child with XY chromosomes will have internal undescended testes. Because they produce MIF, the Fallopian tubes, uterus and upper vagina do not develop. Because Because they do not respond to androgens, they develop female genitalia. People People with CAIS, including Christie North Have A Female External Phenotype Intersexuality: Partial Androgen Insensitivity Syndrome (PAIS) The Gender Puzzle Video With partial androgen insensitivity (1/4500) partial caused by a mutation in the androgen receptor, a child with XY chromosomes will be born with ambiguous genitalia and secondary sex characteristics. Androgen Androgen Receptors The The androgen receptors ligandare ligand-activated that regulate gene that expression. That That is, when they bind androgen, they move into the nucleus and turn on genes. Intersexuality: Dihydrotestosterone (DHT) Deficiency Dihydrotestosterone Dihydrotestosterone is a more potent androgen than testosterone testosterone. The The enzyme that converts testosterone to dih dihydroxytestosterone is 5-alpha reductase. reductase. A 5-alpha reductase deficiency in an 5XY person results in an androgen disorder characterized by a mostly female phenotype. However, during puberty, their testes may descend and their clitoris may be capable of ejaculating sperm. transcription factors 18 Intersexuality: Dihydrotestosterone Dihydrotestosterone (DHT) Deficiency • Intersexuality: Adrenal Hyperplasia A person with adrenal adrenal hyperplasia has an enzyme deficiency that leads to the underproduction of un cortisol cortisol and aldosterone and the overproduction overproduction of androgens. • The overproduction of androgens leads to the masculinization of XX individuals. transgenderzone.com Intersexuality: Adrenal Hyperplasia Judy/Max Beck is Mosaic Hermaphrodite: Some Cells are XY and Some are XO pbs True Hermaphrodite (Mosaic XO/XY) Kailana Sidrandi Alaniz: A Personal Story There are Many Ways to Form Intersexuals http://www.youtube.com/watch?v=6vNzBW0ZNzA http://www.youtube.com/watch?v=TUPOcnXG-vM http://www.youtube.com/watch?v=5_Vph86mz7M http://www.youtube.com/watch?v=ShmwKcfROn4 A mutation in any of the enzymes or receptors mutation enzymes or receptors that that increase the androgen to estrogen activities leads to masculinization. A mutation in any of the mutation enzymes or receptors that enzymes or receptors that decrease the androgen to estrogen activities leads to feminization. 19 Gender Verification in Sports • In the early 1960s, there were rumors that men were secretly posing as women to complete in the Olympics. • By 1966, female athletes disrobed and their genitals were inspected. • Complaints and resentment about this embarrassing approach led the International Olympic Committee (IOC) to search for an alternative gender verification method and in 1968, the IOC required all female athletes to undergo sex chromosome analysis. Gender Verification in Sports • Because of the unreliability of using chromosomes to define an athlete’s sex, in 1992, the IOC tested for the absence of the SRY gene. However, 8 out of 3387 (= 0.2%) female athletes were found to be SRY positive. Of these athletes, 7 had complete (CAIS) or partial (PAIS) androgen insensitivity The other SRY androgen insensitivity. The other SRY-positive female female probably had 5-alpha reductase deficiency. • The IOC has recognized that there is a continuum between males and females and it is a hard to decide where the cutoff is using laboratory techniques. • Since the athletes must urinate under the watchful eyes of the Olympic Committee to test for drugs, males and females are distinguished by the keen eyes of the urine collectors as they were in the Victorian era, by their external genitalia. …and Besides, Body-Sculpting Spandex Almost BodyMakes Gender Verification Unnecessary ‘There's no way with today's spandex uniforms today spandex uniforms that that someone would mistake a male masquerading as a female.' 20 Gender Identity One’s sexual One’s sexual identity is an important aspect in a person’s self identity. While While the concept of two sexes is important for reproduction, it is limiting in terms of the sexual identity of some people. It is only fair to help people find their sexual or gender It is only fair to help people find their sexual or gender identity identity by reducing the secrecy, stigma and taboo nature of disorders in sexual development (DSD). Variations Variations in genes result in a broad spectrum of sexual intermediates between males and females. I have only talked about the genes involved in the have biological determination of sexual identity. Are Are there alleles that cause us to think, act or dress like a stereotypical male or stereotypical female? Environmental Estrogens Could estrogen-like molecules found in the estrogenenvironment increase the degree of feminization? Environmental Environmental Hormones In In order to understand breast breast cancer, Carlos Sonnenschein and Ana Soto were studying cell division. Estrogen causes Estrogen culture cells to divide and they culture cells to divide and they were were looking for the natural inhibitor that put a stop to cell division. All All of a sudden, all their control control cells, which were not given estrogen, continued to divide. What was causing the cells to divide? A Mystery Solved It It turned out that Corning had changed the recipe they used to make plastic tubes and it was something in the new tubes that caused cell division. Corning would not tell them the Cornin name of the new compound used to make the plastic, since it was a trade secret. Sonnenschein Sonnenschein and Soto discovered what the chemical that was leaching from the plastic of the new tubes. It was nonylphenol nonylphenol, which is a synthetic synthetic estrogen, similar to the estrogen nonoxynol-9, used in nonoxynolcontraceptives. www.cmog.org Other Environmental Estrogens Thalates: Thalates: plastics industry Alkylphenols Alkylphenols (nonylphenol): detergents and cosmetics Bisphenol Bisphenol A: Used to coat foods and in dental sealants Lindane: Lindane: pesticide used on cereals, soft fruits, cabbage Vinclozolin: Vinclozolin: fungicide used on foods Phytoestrogens: Phytoestrogens: soy products Estrogens: Estrogens: estrogens from birth control pills, rings etc., and hormone replacement therapy that are eliminated in the urine. Cornell U Environmental estrogens Male Fertility and Environmental Estrogens In In many places throughout the world, male male fertility is declining. Environmental Environmental estrogens are a factor correlated with declining semen correlated with declining semen quality quality (concentration of sperm, % normal morphology, % motile). However, However, the decrease in semen quality may be caused by many caused environmental, behavioral, nutritional and developmental factors, including environmental estrogens. 21 Human Sperm Suppression Environmental Endocrine Disruptors and the Increase in Intersexes? There There is a high proportion of intersex fish in populations living downstream from waste treatment plants. There is a reduction in reduction From the Study of Scottish Male Reproductive Health www.link.med.ed.ac.uk/ HEW/repro/default.htm alligators living in Florida. Female alligators have penis penis size and testosterone levels in normal— normal—both effects are probably due to a breakdown product of the pesticide DDT. estrogen estrogen levels that are two times higher than Law of Malthus The food The food supply grows arithmetically and the population grows geometrically. We must ensure that there is enough food for each person. We have discussed methods to di increase the food supply. There There are a number of methods that Some Methods for Separating Sex from Fertilization Sex from Fertilization reduce reduce the chance of conception and an unwanted pregnancy. Depending Depending on your views of when life begins, there are various methods that prevent birth. prevent Teen Teen Pregnancy: It is Important to Separate Sex from Fertilization Behavioral Behavioral Abstinence Abstinence (no intercourse) Elimination Elimination of rape Homosexuality Homosexuality Surgical Surgical Tubal Tubal ligation (Fallopian tubes tied) Vasectomy Vasectomy (vas deferens cut) Physical Barrier Physical Barrier Diaphragm Diaphragm Condom Condom Chemical Chemical Spermicide Spermicide Hormonal Hormonal Oral contraceptives Vaginal Vaginal ring Contraceptive Contraceptive patch www.cdc.gov 22 Contraceptives: Each has Risks and Benefits Failure Rates of Contraceptive Methods teenwire plannedparenthood www.soc.ucsb.edu/sexinfo/ Abstinence also has a Failure Rate Intrauterine Device (IUD) Ernst Ernst Grafenberg (1927), who the “G spot” (the female homolog of the prostate prostate gland) is named is after, was interested in the medical emancipation of medical emancipation of women. women. He He designed an intrauterine intrauterine ring made made out of “German Silver” wire, which contained 26% copper as a contraceptive. There There are many modern designs and each one has a string that indicates that the IUD IUD is in place. String of IUD in the Uterus Passes through the Cervix into the Vagina Dalkon Shield There There is normally no bacteria in the uterus, Fallopian tubes and ovaries. In In most IUDs, there is a single monofilament string that goes between the IUD in the uterus and the vagina. The Dalkon The Dalkon Shield had a multifilament multifilament string that acted as a wick and pulled bacteria from the vagina into the uterus. The The bacteria, including Chlamydia Chlamydia and Gonorrhea caused pelvic Gonorrhea pelvic inflammatory disease (PID) which can destroy the ovaries, causing sterility and the Fallopian tubes causing ectopic pregnancies. www.cdc.gov/ 23 Intrauterine Devices (IUDs) The The Dalkon Shield was the only IUD that had a multifilament string. All All other IUDs have a monofilament string and monofilament string and have have a low risk of causing PID. ParaGard ParaGard is one modern hormonehormone-free version of the IUD. Mirena Mirena is a modern IUD that contains progesterone which reduces menstrual bleeding. Advertising by the Pharmaceutical Company Influences Our Common Sense mirena paragard.com www.cdc.gov Critical Thinking and Making Decisions with Incomplete Knowledge The The Dalkon Shield experience gives IUDs a bad name to this day. IUDs are the most effective form of contraception for people contraception for people who have sex (99.4% effective). (Abstinence is the most effective form of contraception for people who do not have sex). IUDs are the most widely-used form of contraception worldwide. Critical Thinking and Making Decisions with Incomplete Knowledge An IUD is a reversible form of contraception and can last up to 10-12 years, making it the most inexpensive form of contraception. IUDs increase the possibility of increase the possibility of getting an infection that leads to PID and women who have a high risk of getting vaginal infections should not use IUDs. IUDS do not protect against sexuallytransmitted infections (STIs). It is important to check the string because IUDs can be expelled from the uterus without the woman knowing. Male Birth Control Pill Frances Frances Platt noticed that men treated with NNbutyldeoxynojirimycin (NB-DNJ, (NBZavesca), a drug that was being tested for treating Gaucher’s disease became temporarily disease, became temporarily infertile. infertile. She She then began to test the drug on mice and found that it reversibly inhibited sperm development, making the mice infertile. Unfortunately, Unfortunately, clinical trials show that it does not work on humans. http://www.malecontraceptives.org/ Intercourse Involves Two People: Use Your Head When it Comes to Sex www.chooserespect.org 24 Informed Consent Informed Informed consent is a legal condition in which a person gives his/her consent based upon an appreciation appreciation and understanding of the facts and implications of an action. The individual needs to be in possession of all of The individual needs to be in possession of all of his/her his/her faculties. To To give informed consent, a person cannot be without an impairment of judgment at the impairment time of consenting. Such impairments include intoxication drunkenness intoxication, drunkenness and using drugs. using Make Make all your important decisions based on informed consent. The Most Underreported Crime— Crime— Prepare Your Mind for the Possibility www.ncjrs.gov www.ncjrs.gov -1 www.aauw.org http://www.soc.ucsb.edu/sexinfo/ 25 Date Rape Drug Test Strips and Coasters Methods that Prevent Birth after Unplanned Intercourse Emergency Emergency Contraception (e.g. Plan B) can be Plan used within 72 h after unprotected sex and prevents ovulation, fertilization and/or the implantation of the embryo in the uterus. Plan B contains a progestin. progestin RU48 RU486 can be used 7-9 weeks after 7unprotected sex. It competes with competes progesterone for the progesterone receptor and the prostaglandin in it initiates contractions contractions so the softened uterine wall is no longer maintained and the embryo is expelled with the menstrual flow. Surgical Surgical abortion Plan B nrlc.org plannedparenthood.org now.org naral.org http://www.drinksafetech.com/ fda.gov-mifepristone Roe v. Wade: Two Sides Sex Education “The core of the modern sexual code is disease prevention….sex ed ti is not a form of moral education. It is a branch of hygiene. ” playing catch up on morality With All the Talk about Sex, Don’t Forget Love “I would follow in the footsteps of other deans in overseeing a lot of oversee talk talk about sex but would break new ground by writing a Crimson column about love.” --Harry --Harry Lewis romance and love at harvard Gannett Health Services (Weblinks) Birth Birth Control Pregnancy Pregnancy Disease Disease (STI) Prevention Sexuality Sexuality and Relationships Sexual Sexual Health Care Sexual Sexual Assault (or call me, since this is something I will not tolerate). Gannett Gannett Health Services 26 ...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online