BIO 101 1nd Edition Lecture10 Outline of Last Lecture II Asexual Reproduction III Sexual Reproduction IV Fission V Budding VI Parthenogenesis VII Hermaphroditism Outline of Current Lecture VIII Male anatomy IX Female anatomy X Hormones in uterus XI Semen XII Contraception XIII Fertilization XIV Birth XV Infertility XVI Birth control Pills Current Lecture These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Similarities A pair of gonads the organs that produce gametes o Testicles o Ovaries Start out inside body o Testicles descend before birth A system of ducts that store and deliver gametes Fetus begins with starter parts that could develop into either gender Male or Female DNA determines baby s gender o In some species of plants and animals but not all species XX human female XY Human Male Depends on which egg and sperm get together Father determines baby s gender in humans Around 7th week Baby s body is told by DNA to become either male or female Unused pats disintegrate Used parts continued Development Human Male anatomy Urine and sperm are conveyed through a tube called the urethra The penis contains erectile tissue that when filled with blood produces an erection The male gonad is the testis The scrotum is an external sac that holds the testes and keeps them slightly cooler than body temperature Within the testes diploid cells divide via meiosis to produce haploid sperm cells 23 chromosomes This is the process of spermatogenesis o Humans have 46 Chromosomes Human Female anatomy The ovary is the female gonad where oocytes are produced and released The uterus is the site of pregnancy where an embryo develops into a baby The vagina or birth canal is where sperm enters and a baby exits The oviduct fallopian tube is the site where egg meets sperm The vulva is collective name for all the external female reproductive structures Within the ovary during the process of oogenesis a mature haploid egg called an ovum develops 23 chromosomes Formation of an oocyte Ovaries o 2 pouches contain ova Born with all of her eggs 400 000 Use up to 500 Ovulation o Typically only one oocyte is released from ovary to oviduct fallopian tube Ovulation the release of an oocyte cell from the ovaries may occur around day 14 This varies for many women 28 Day Cycle average Three Stages 1 Tear down 2 Rebuild 3 Extra nutrients blood for potential baby No baby o Back to 1 Hormones in the Ovaries Day 1 7 Follicles enlarge due to increasing levels of follicle stimulating hormones FSH Day 8 13 Enlarging follicle secretes increasing amounts of estrogen Day 14 surge of leutinizing hormone LH induces ovulation Day 14 28 Corpus luteum secretes progesterone After Ovulation Egg pushed along the cilia Few days travel time to arrive in uterus Cervis opening between uterus and vagina o Normally tiny o At birth muscles pull open dilation cervix to allow baby to pass through labor Hormones in the Uterus Day 0 7 Menstruation due to loss of progesterone Day 7 14 Thickening of endometrium in response to estrogen Day 14 28 continued endometrial development in response to progesterone Mid cycle Ovulation oovum released Temp spikes slightly Mot fertile in next few days o Able to get pregnant Egg gets fertilized while traveling through oviduct Endometriosis Endometriosis is a painful disorder in which the tissue that normally lines the inside of the uterus grows outside your uterus Displaced endometrial tissue continues to act as normal it thickens breaks down and bleeds with each menstrual cycle But this broken down tissue has no way to exit the body When endometriosis involves the ovaries cysts may form Surrounding tissue can become irritated eventually developing scar tissue and adhesions abnormal tissue that binds organs together Fertility problems may also develop Male Testes o Produce 2 4 million sperm every day o Outside body why Sperm like temps 1 2 cooler than body temp Vas Deferens o Tube sperm travel through Vasectomy o Cut tie off tube sperm can t get out Semen Contains o 300 500 million sperm o Sperm food o pH buffers Allows sperm to survive for a couple of days inside female s body hostile environment What is sperm Then o Used to think it was a tiny human inside each cell o Spermists vs Ovists Now o Contains Several Parts Head Chemical to dissolve egg goo Dad s genetic information DNA o Body with Mitochondria Energy o Tail Swimming Prostate Gland Adds necessary chemicals to support the lives of the sperm to semen o pH buffers o Nourishment proteins carbohydrates Cancer very common o Slower growing usually o Surgery for removal Bulbourethral Gland Ads lubricant to aid travel of semen through the urethra Conception Fertilization Ejaculation o Release of 300 500 million sperm Egg needs to be in oviduct Sperm to egg not an easy task o Go wrong direction 2 paths only 1 leads to an egg o Get attacked by female s white blood cells o Acidic environment o Current Myth In the traditional model the oovm passively waits for the sperm s arrival and the sperm breaks through the oovm s protective coat through mechanical burrowing Now we know both sperm and oovm play active roles The oovm o Binds and draws in the sperm as well as blocking out extra sperm o Oovm engulfs sperm by protrusion of cytoplasm o After a sperm makes it through the egg hardens The sperm o Tails are actually weak Side to side motion of tails results in same motion in heads but far more powerful As a result rather than forcefully overcoming the egg s barrier the head thrashes as if to move away The egg holds the head in place The oovm and sperm must recognize one another in order to proceed to fertilization They have complimentary proteins on their cell surfaces Fertilization Dissolve protective goo surrounding egg One gets through enters egg Instant biochemical change in zygote o No more sperm allowed in Implants in uterine Lining Endometrium is the lining of uterus Uses mother s nutrients Continues development Fetal Development Anmion o Membrane surrounding baby o Contains amniotic fluid o Breaks just before birth water broke Amniotic Fluid o The water surrounding baby o Buoyant cradle for baby Protection Free movement Umbilical Cord o Blood vessels from placenta to baby o Mom s baby s blood do not circulate together Can have 2 different blood types Diffusion Birth Labor muscles used to open cervix Baby flips upside down o Head first o Feet first Breech o