Gamete Production and Fertilisation PDF

Gamete productionand Fertilisation EEi sFtion distances...

Gamete productionand Fertilisation EEi sFtion distances huge 11 to travel Male reproductive system the testes Gametes spermatozoa produced by meiosis in Sperm production takesplace in seminiferous tubes Binetmmed Theseconnect tothespermductsperm thengototheurethraforEJACULATION acts on glandesides tn between seminiferoustubes produce testosterone thique's it fr titiagellsin EEEEi i eeis Ettore ystemisfttÉÉ É ÉÉfÉ external are ffff I IEEE its I iii v mate II Y shaft tiaifh retisu penis Female reproductive system trud gutqfgis.ee HasCYCLICALfertility implanted no blastocyst eeaegei internal wheaten Urinarytracturethra is separate outed Vulva is external repent she gifefsation mature may yg.ee of via frisis immature contains Eichiti Tepaired tube monthly EEEEE.tttatomuct oestrogen secretigesterone secretes cellular sac re EE If fE ie e E IEII merge Hormonal Control ofReproduction HormonalOnset ofPuberty Puberty transition tosexualmaturity causingmaturationofsexual organs spermproduction in malesmenstruation infemales andthe of development secondary sexual characteristics HormonalOnset secretes FSH follicle stimulatinghormone ICSH interstitialCellStimulatingHormone inmalesand LH luteinizingHormone infemales Sexual Characteristics HormonalControl of SpermProduction regulated Pituitary self process Iiii ESH ISH one it Testosterone supportsspermproduction activates seminalvesiclesandprostateglands help producesemen Hormonal control of tgg.ge iiihfiii as menses EE c.ie e EEtiis bleeding pituitary start ofmenses in i corpusluteumsecretes EEi ai Fe inIii iiii.is www.mament Eti iE ofthecorpusluteumf.ro iifiie.gg thefollicle I i iii Iiii.it i Eii PregnancyZygote secretes hormone which prevents the next menstrual cyclefrom occurring Corpusluteum continues to produce progesterone Placenta later takes over progesteroneproduction we bodytemperature body temperature  ugh Rhythmmethodtracking ofcervicalmucus viscosity andbody temperature topredict Controlling Fertility a woman'sfertilewindo Infertility treatments II II.IEIii ii Low sperm countnon viable spent ifiei iii Fails iiie i ifeng.ie g prod Tuality testic productions taste infection or injurye fission g PoorEggQuality Blockedspermducts noneggsfroma Ian Eft Surgeryto eradicate blockages SmokingIntake jtion stress Disease There's Age Hormonal malfunction Blockageoftubes scartissue Effigy Genetic Disposition Fertile Periods Continuous fertility asFSHICSH levels don't change muchtestosteronelevelandspermproductionremainsrelativelyconstant so males can reproduce at ANYTIME caused bynegative of FSHandICSH feedback control CyclicalFertility Femaleshave a short fertileperiod 1 2days linked to a cycle of events the menstrual cycle sperm cansurvive for several daysafterintercourse and fertilise an egg cervicalmucus prev etdrE8 de itnfreed Body temperature dropsthenrises during ovulation microbialgrowth 598 E5 EaagsmEr SEE.EE technically EYE to This ite bodyftp.araiysesaefzroiPif 2dayslong EE E Eieespitse Treatments 1 Ovulation Stimulation drugs prevent from inhibiting FSH secretion oestrogen Drugs mimic FSHand LH causing SUPER OVULATION Several ova may be released these can be collected for NF 2 Artificial Insemination Sperm samples collected cleaned and inserted using alternate methods to intercour Low sperm count samples can be combined If the partner is sterileinfertile thenasperm donor can be used 3 Intracytoplasmic sperm Injection ICSI single sperm injected with glassneedle intoovum occurswhen sperm are defectivelow sperm count 4 Invitro Fertilisation NF Ova removed surgically after hormone stimulation Mixed with sperm in a culturedish eggs incubated in nutrient medium Fertilised After 8 cellshave formed they are implanted intothe uterus Eggs can beused for stem cell research Preimplantation GeneticDiagnosis PGD check for single gene chromosomal disorders Unused embryos frozen for later use Contraception prevention of conception pipitate IntrauterineDevice IUD copperplastic device placed in uterus to preventimplantation Barriers Physical Methods of stoppingfertilisation condomcervical e.g cap diaphragm Sterilisation Surgical incisionandsealing of sperm ducts sperm don't enter semen Chemical Oral contraceptive pill synthetic progesterone andoestrogen inhibit FSH and LH release in thepituitarygland MorningAfter Pill If original contraception method failed High levels of synthetic progesterone and oestrogenprevent ovulation and implantation Cervical mucus thickens toprevent penetrationby thesperm Progesterone only mini pill synthetic progesterone inhibits FSHand LH secretion in the pituitarygland as well as thickening the cervicalmucus  Antenatal postnatal Screening Antenal screening method ofdetecting issueswithembryofetusbeforebirth eg possible genetic conditions Bloodgroup sex anddeliverydatealsodetermined invasiveandused inthefirst6monthsofpregnancy Mainlynon Ultrasound Imaging Highfrequencysoundwavespassed through abdominal wall tocreate an image of thefetus 2 scansduringpregnancy Dating scan 814weeks determines stage of pregnancyandpredicts delivery date used withbiochemical tests for chemical markers e.g proteins Anomalyscan 1820weeks detects serious physical abnormalities in thefetus Biochemical Testing of Blood andurine Blood sample detectsprotein levels produced in theplacenta Monitormarker chemicals to identifypossiblemedicalconditions e.g to identify Down's syndrome catypical levels of a particularprose Wrongtiming can causefalse positives by eradicated datingscans Diagnostic Testing Samples from placenta amniotic flood or fecalblood to check forchromosomalgenetic abnormalities Amniocentesis Identify birthabnormalities mainly in thebrainspinal cord Sample from amniotic fluid removed using a needle betweens the 1520thweeks of pregnancy Amniotic fluid has cells shed from fetus used for genetic analysis Offered towoman over 35 whoseblood test indicates potential abnormalities 11 risk of miscarriage Chorionic Villus Sampling CVS Diagnosis of congenital abnormalities Offered to women with genetic historyblood test indicating potential abnormalities Longflexible tube inserted into cervix through vagina to take sampletissue from the PLACENTA and villi with the samegeneticmaterial asthe chorionic Between weeks 1013 can't detect defects in CNS development 12 risk of miscarriage Karyotype visual record of chromosomesarranged inhomologouspairs can be produced Allows diagnosis of genetic conditions by observing abnormalities in shapeno of chromosomes e.g Dow sydrome Inheritance Patterns Pedigree chart indicates how a genetic trait is expressed overseveral generations of a family Indicates risks of developing dangerous e.g Huntington's conditions disease Data collected to produce phenotypes and genotypes offamilymembers 4 inheritance patterns Defective recessive autosomalinheritance autosomalallele caused by defective recessive Rarely expressed Skips generations Equal effect on male andfemale Affectived must be individual homozygous recessive but can be carrie a heterozygous individual by Eg Albinism Defective autosomal dominant allele Affects males females in equal numbers Anyone affected has an affected parent if a branch doesen't show thedisorder ie is homozygous recessive it won't appear in future generations Anyone affected will be heterohomozygous Eg Huntington's disease Autosomal Defective Allele Affects malesfemales in equal numbers Heterozygous state produces reducedexpression of thephenotype Homozygous state produces maximum expression of phenotype Craneas the alleles are incompletely dominantovereach other E.g sickle cell disease Defective sexlinked recessiveallele Affects more malesthan females  Not transmitted to male fromhis affected father Affected female must be homozygous Affected male has 1 copy of affected allele Not in male whohas thenormalallele expressed All daughters of affected fathers will be carriers or affected Mother of affected male is usually unaffected Eg haemophilia Postnatal Screening Diagnostic testing for abnormalities in the babyAFTERbirth PKU asubstitution mutation stopping an enzyme from phenylaine Fo Eg phenylketonuria converting tyrosine is screened for using a blood sample fromthe baby's heel restricted diet with low phenylalanine levels prescribed e.g no cereal or potatoes Prevents malfunction improper development of thebrain continued into adulthood