Reproduction in Humans

Name: __________________ Topic: Reproduction in Humans LO:Identifyondiagrams,themalereproductivesystemandgivethefunctionsof:testes, scrotum, sperm ducts, prostate gland, urethra and penis Testes Producesspermsandmale sex hormone, testosterone Scrotum Keeps the testes outside the main body so that spermscan develop properly atlower temperature Sperm duct (vasdeferens) Carry sperms from testes to the urethra Prostate gland Produces alkaline, milky fluid that containsnutrientsandenzymeswhichnourish andactivates the spermsandhelps them to swim towards the egg.Urethra Passes the sperms out of the bodyPenis Erectile tissue, allowing it to enter and deposit sperms inthe vagina Concepts Summary NotesNan Hua High School Biology 1

Name: __________________ Topic: Reproduction in Humans LO:Identifyondiagrams,thefemalereproductivesystemandgivethefunctionsof: ovaries, oviducts, uterus, cervix and vagina Ovary Produceova/ eggsandfemale sex hormones, estrogenandprogesterone Oviduct ● Transports eggs to the uterus byperistalsisof themuscularwallandsweeping action of the cilia.● Site of fertilisation Uterus(womb) Site ofimplantation of embryoand fetus developmentduringpregnancyCervix Enlarges to allow passage of the fetus during birth Vagina Where semen is deposited during sexual intercourse; birth canal Concepts Summary NotesNan Hua High School Biology 2

Name: __________________ Topic: Reproduction in Humans LO:Brieflydescribethemenstrualcyclewithreferenceto thealternationofmenstruationandovulation,thenaturalvariationinitslength,andthefertileandinfertilephasesofthecyclewithreferencetotheeffectsofprogesteroneandestrogen only ● The average menstrual cycle is28 days.● The menstrual cycle can range from21 to 33 days. Fertile period● An egg can survive for 2 days, whereas sperms can live for 3 days.● Ovulation usually occurs on day 14.● Chance of getting pregnant is highest betweendays11 to 16.● The rest of the days make up the infertile period. Concepts Summary NotesNan Hua High School Biology 3

Name: __________________ Topic: Reproduction in Humans Day 1-5● Menstruation occurs● The first day of menstruation is the first day of the menstrual cycle● Duringmenstruation,theuterineliningbreaksdownandflowsoutthroughthevagina● Low levels of estrogen and progesterone Day 6-13● Follicle-stimulatinghormone(FSH)releasedbyanteriorpituitaryglandstimulatesdevelopment of primary follicle in one of the ovaries● Thedevelopingfolliclesecreteshormone,estrogenfortherepairandgrowthofthe uterine lining.● Estrogen level increases. Day 14● Follicle matures to becomeGraafian follicle● Increasein estrogenproductionstimulatesthe pituitaryglandto releaseluteinizing hormone (LH)● Ovulation occurs wherebya mature egg/ovum is releasedby the Graafian follicle Concepts Summary NotesNan Hua High School Biology 4

Name: __________________ Topic: Reproduction in Humans Day 15-28● The remaining follicle forms the corpus luteum.● Progesteroneandestrogenareproducedbythecorpusluteumtomaintainthethicknessoftheuterineliningandsupplyingitwithbloodcapillariestoprepareforimplantation of embryo.● Iffertilisationdoesnotoccur,thecorpusluteumwilldegenerateandproductionofprogesterone drops.Uterine lining can no longer bemaintained.● If fertilization occurs,progesterone levels remainshigh.● Cycle goes back to day 1 and repeats. Concepts Summary NotesNan Hua High School Biology 5

Name: __________________ Topic: Reproduction in Humans LO:Describefertilisationandearlydevelopmentofthezygotesimplyintermsofthe formation of a ball of cells which becomes implanted in the wall of the uterus ● Semen is deposited into the vagina.● Sperms travel up through the cervix and uterus and enters the oviduct.● When the sperms reach the egg,sperms release acrosomeenzymes to breakdown the egg membrane.● Only onesperm nucleus enters the egg.● When thehaploid nucleus of spermfuses with thehaploidnucleus of egg/ ovumto form adiploid zygote, fertilisation occurs. Fertilisationtakes place in theoviduct.● The zygote moves from the oviduct to the uterus. It isswept by cilia andperistalsis of the oviduct muscles.● The zygote undergoesmitosisto form a ball of cellscalled theembryo, whichgetsimplantedin theuterine liningon the wall ofthe uterus. LO: State the functions of the amniotic sac and the amniotic fluid Concepts Summary NotesNan Hua High School Biology 6

Name: __________________ Topic: Reproduction in Humans The amniotic sac contains amniotic fluid, which allows the fetus to move within. Amniotic fluid has the following functions:● Supports and cushionsfetusbefore birth● Absorbs shock (if mother has afall)● Protects fetus fromphysical injury● Lubricatesandreduces frictioninthe vagina during birth● Allowsfetus to move freelyduringgrowth● Preventstemperature fluctuations LO:Describethefunctionof theplacentaandumbilicalcordin relationtoexchangeofdissolvednutrients,gasesandexcretoryproducts(structuraldetailsare not required) ● The placenta producesprogesteroneto maintain andthicken the uterine lining. Concepts Summary NotesNan Hua High School Biology 7

Name: __________________ Topic: Reproduction in Humans ● Site of exchange of substancesbetween mother and fetus:1. Italsoallowsnutrientssuchasglucose,aminoacidsandoxygentodiffusefrom the mother’s blood to the fetus’s blood.2. Metabolicwasteproductssuchasureaandcarbondioxidediffusefromthe fetus’s blood to the mother’s blood.3. Antibodiesfromthemother’s bloodcandiffuseintothefetus’s bloodtoprotect the fetus from diseases.● Umbilicalarteries(two)transportdeoxygenatedbloodandmetabolicwasteproductssuch as urea and carbon dioxide from thefetus to the placenta.● Theumbilicalveintransportsoxygenatedblood,antibodiesandnutrientssuchasglucose and amino acidsfrom theplacenta to the fetus.● The bloodsystemof the motherandfetuscannotmix dueto possibleagglutinationandthedifferencein bloodpressureofthemotherandthefetusmay kill the fetus. LO:Discussthespreadofhumanimmunodeficiencyvirus(HIV)andmethodsbywhich it may be controlledModes of transmission● Having sexual intercourse with an infected person● By sharing needles with an infected person● Through blood transfusion with blood from an infected person● During pregnancy when an infected mother passes the virus to her fetus Prevention and control● Keep to one sex partner● Use a condom● Sterilise needles before use (e.g. for ear piercing or tattooing)● Do not share instruments likely to break the skin (e.g. razors and toothbrushes) Concepts Summary NotesNan Hua High School Biology 8