Fundamentals of Human Reproduction LECTURE 1 o Introduction Sexual Differentiation Prenatal in utero development of the male and female reproductive structures The physical difference between male and female reproductive structures Genetic sex o Established at fertilization XX female XY male o Hormones and Sexual Differentiation of the Brain Ex Book carrying differences Some explanations include o Body posture way limbs are held o Females often fold their arms in front of the body o Males more open posture Ex Finger length o Men right finger index finger o Women index finger ring finger o Sexual Differentiation Y chromosome induces the indifferent gonads neither male nor female to become testes This differentiation begins approximately during th 6th 7th week of gestation The testes produce two hormones o Androgens which will act on the Wolffian duct system to induce internal male reproduction structures and on the external genitalia to induce male external structures o Mullerian duct inhibiting hormone MDIH which will act on the Mullerian duct system to cause them to generate Wolffian Ducts respond to androgens to form seminal vesicles vas deferens and epididymis Mullerian ducts inhibited by MDIH o Male Differentiation see chart in book In summary the Wolffian Ducts are induced by testosterone to form the o Seminal vesicles o Vas deferens o Epididymis Internal Structures o Ejaculatory Ducts Lead to urethra and junction of ducts of seminal vesicles and vas deferens o Prostate Gland sperm cells Thin milky fluid helpful in sperm motility and buffers External genitalia in the male respond to potent androgen called dihydrotesterone to become male structures including o Scrotum penis and prostate gland o Receptors only respond testosterone and cell changes it to o IClicker If we prevented testosterone from being changed to DHT we DHT woud not find Penis o Female Sexual Differentiation see book If androgens are absent the Mullerian ducts will develop into internal female reproductive structures including o Oviducts uterus and portion of the vagina Internal structures o Ovaries Under control of FSH LH If no androgens are present no hormonal input then female external structures develop into o Clitoris labia and vagina o IClicker an individual with a genotype of XXY would have Testes o Homologous Structures It is clear that males and females are different but the reproductive structures develop from the exact same tissues If androgens are present the tissues become male structures and without androgens they become female structures The structures are termed homologous structures o Scrotum labia majora o Penis clitoris o Cowper s glands Bartholin s glands o Testes ovaries o The Critical Role of the Y Chromosome Y chromosome directs the male reproductive system structures due It is the androgens male hormones from the developing testes that to testes are critical o Andrenogenital Syndrome The adrenogenital syndrome can affect both genders and roughly 1 in every 10 000 to 18 000 children are born with the condition The syndrome will cause an excess of male sex hormone to be As a result whether on a male or female male characteristics will For girls it is possible the girl s genitals will look similar to males produced begin to develop ambiguous genitalia Treatment for AGS book Fundamentals of Human Reproduction 02 27 2013 LECTURE 2 o iClicker With AGS XX we would find Ovaries o iClicker Will Mullerian ducts become internal female reproductive structures in an XX AGS child Yes There is no anti Mullerian hormone being produced here o iClicker Will the Wollfian ducts become internal male structures in a XX AGS child No o Summary A female with AGS will have o Ovaries oviduct uterus vagina be fertile have some masculinization of external genitalia o Female with XX has no androgen normal internal structures o Androgen Insensitivity Syndrome Two to five out of 100 000 births will have complete syndrome o Some will have partial or mild form o All individuals will have the genotype XY Receptors are the key to this syndrome Cells of body do not respond to androgens from the abdominal Wollfian Ducts are insensitive to male hormones androgens no male internal structures will occur except testes o No internal male structures iClicker Will an individual with AIS have female internal organs testes o No o External Structures of Male Penis o Erectile tissue Corpora cavernosa penis Corpus spongiosum penis Urethra Erection is a vascular phenomena iClicker Through which part of the penis does the urethra pass Scrotum o Function through o Corpus spongiosum penis Fundamentals of Human Reproduction 02 27 2013 LECTURE 3 o Male Circumcision Study done in Africa Male circumcision significantly reduces the incidence of male HIV infection MC protects males from infection by HIV infected partners No protection from females Inner mucosa of foreskin is rich in HIV target cells External foreskin shaft keratinized and not vulnerable After circumcision only vulnerable mucosa is urethra meatus Moist sub preputial space increase HIV survival Also lowers the risk of other STDs penile cancer and infant urinary o MC Continued tract infection In female partners it reduces the risk of cervical cancer genital ulceration bacterial vaginosis trichomoniasis and HPV Decisions of the American Academy of Pediatrics from 1971 2012 o 1971 1975 1983 There was no absolute medical indication for routine circumcision o 1999 Male circumcision could reduce risk of UTIs and has other potential medical benefits and advantages and disadvantages o Ideas are always changing The US has the highest rate of MC however numbers have fallen o Rates vary by part of the country religion ethnicity etc o Internal Structures of Male Testes o Leydig cells produce male hormones androgens o Seminiferous tubules sperm production o Both of these activities under control of LH and FSH gonadotropins from anterior pituitary o Sperm mature here for approximately 10 days o Ampulla is storage area for sperm cells o Thick mucous secretion essential for motility of sperm cells o Lead to urethra and junction of ducts of seminal vesicles and Epididymis Vas Deferens Seminal Vesicles Ejaculatory Ducts vas deferens Prostate Gland o Thin milky fluid helpful in sperm motility and buffers sperm cells while in female tract Cowper s Glands o Pre ejaculatory emission o External Structures of Female External Structures are called the Vulva o Labia majora o Labia minora o Clitoris
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