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  • Figure 46.10 Reproductive anatomy of the human female
  • Figure 46.10 Reproductive anatomy of the human female
  • Figure 46.11 Reproductive anatomy of the human male
  • Figure 46.11 Reproductive anatomy of the human male
  • Figure 46.12 Human gametogenesis
  • Figure 46.12 Human gametogenesis
  • Figure 46.12 Human gametogenesis
  • Figure 46.12 Human gametogenesis
  • Figure 46.12 Human gametogenesis
  • Figure 46.13 Hormonal control of the testes
  • Figure 46.14 The reproductive cycle of the human female
  • Figure 46.14 The reproductive cycle of the human female
  • Figure 46.15 Formation of the zygote and early post-fertilization events
  • Figure 46.16 Placental circulation
  • Figure 46.17 Human fetal development
  • Figure 46.18 A model for the induction of labor
  • Figure 46.19 The three stages of labor
  • Figure 46.19 The three stages of labor
  • Figure 46.19 The three stages of labor

Unit 6  human reproduction Unit 6 human reproduction Presentation Transcript

  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsPowerPoint®Lecture Presentations forBiologyEighth EditionNeil Campbell and Jane ReeceLectures by Chris Romero, updated by Erin Barley with contributions from Joan SharpChapter 5Human ReproductionCAMPBELL & REECECHAPTER 46
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings1. Female Reproductive Anatomy• The female external reproductivestructures include• the clitoris and• two sets of labiaAnimation: Female Reproductive AnatomyAnimation: Female Reproductive Anatomy
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• The internal organs are:– a pair of gonads (ovaries) and– a system of ducts (oviducts/fallopian tubes) and– chambers (uterus,vagina, vulva)that carry gametes and house theembryo and fetusAnimation: Female Reproductive AnatomyAnimation: Female Reproductive Anatomy
  • Fig. 46-10a(Rectum)CervixVaginaVaginal openingOviductOvaryUterus(Urinary bladder)(Pubic bone)UrethraClitorisShaftGlansPrepuceLabia minoraLabia majoraReproductive anatomy of thehuman female
  • Fig. 46-10bOvariesOviductFolliclesCorpus luteumUterine wallUterusCervixEndometriumVaginaReproductive anatomy of the humanfemale
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsa. Female gonads: Ovaries• Lie in the abdominal cavity• Each ovary contains– many follicles, which consist of apartially developed egg, called anoocyte, surrounded by support cells.• Once a month, an oocyte develops into anovum (egg) by the process of oogenesis
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Ovulation is the release of an egg cell fromthe follicle.• The remaining follicular tissue grows withinthe ovary, forming the corpus luteum.• The corpus luteum secretes hormonese.g. that help to maintain pregnancy.• If the egg is not fertilized, the corpusluteum degenerates.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsb. Oviducts and Uterus• After ovulation, the egg cell travels from theovary to the uterus via an oviduct, orfallopian tube.• Cilia in the oviduct convey the egg to theuterus, also called the womb.• The uterus lining, the endometrium, has manyblood vessels• The uterus narrows at the cervix, then opensinto the vagina.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsc.Vagina and Vulva• The vagina: is a thin-walled chamber thatis the repository for sperm duringcopulation and serves as the birth canal• The vagina opens to the outside at thevulva, which consists of the– labia majora,– labia minora,– hymen, and– clitoris
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsd. Mammary Glands• The mammary glands are not part of thereproductive system but are important tomammalian reproduction.• Within the glands, small sacs of epithelialtissue secrete milk.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings2. Male Reproductive Anatomy• The male’s external reproductiveorgans are:– the scrotum and– penisAnimation: Male Reproductive AnatomyAnimation: Male Reproductive Anatomy
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings2. Male Reproductive Anatomy• Internal organs are:– the gonads (testes), whichproduce sperm and hormones,– and accessory glandsAnimation: Male Reproductive AnatomyAnimation: Male Reproductive Anatomy
  • Fig. 46-11aSeminalvesicle(behindbladder)UrethraScrotum(Urinarybladder)Prostate glandBulbourethralglandErectile tissueof penisVas deferensEpididymisTestisReproductive anatomy of thehuman male
  • Fig. 46-11bSeminal vesicle(Rectum)Vas deferensEjaculatory ductProstate glandBulbourethral glandVas deferens EpididymisTestisScrotum(Urinarybladder)(Urinaryduct)(Pubic bone)ErectiletissueUrethraGlansPrepucePenisReproductive anatomy of thehuman male
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsa. Male gonads: Testes• Testes, consist of:– highly coiled seminiferoustubules (in which sperm form)– surrounded by connective tissue– Leydig cells produce hormonesand are scattered between thetubules.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Production of normal sperm cannotoccur at the body temperatures .• The testes are held outside theabdominal cavity in the scrotum,where the temperature is 2ºC lowerthan in the abdominal cavity.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsMALE TESTIS ANATOMY
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsb. Ducts• From the seminiferous tubules of atestis, sperm pass into the coiledtubules of the epididymis• During ejaculation, sperm arepropelled through the muscular vasdeferens and the ejaculatory duct,and then exit the penis through theurethra.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsc. Accessory Glands• Semen is composed of:– sperm plus– secretions from three sets of accessoryglands• The two seminal vesicles contributeabout 60% of the total volume ofsemen.• The prostate gland secretes itsproducts directly into the urethra throughseveral small ducts.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsc. Accessory Glands– The bulbourethral glands secrete a clearmucus before ejaculation that neutralizesacidic urine remaining in the urethra.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsD. Penis• The human penis is composed of threecylinders of spongy erectile tissue.• During sexual arousal, the erectile tissuefills with blood from the arteries, causingan erection.• The head of the penis is called the glansand is covered with a prepuce.• The rest is called the shaft.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsD. PenisGlans Shaft
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings3. GAMETOGENESIS• Gametogenesis, the production ofgametes by meiosis.• Spermatogenesis is production ofmature sperm• Oogenesis is development of matureoocytes (eggs).• Sperm are small and motile and are produced
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsA. Spermatogenesis Sperm are small and motile and areproduced throughout the life of asexually mature male.
  • EpididymisSeminiferous tubuleSertoli cellnucleusTestisCross sectionof seminiferoustubuleSpermatogoniumPrimary spermatocyteSecondary spermatocyteSpermatids(two stages)SpermLumen ofseminiferous tubuleSPERMATOGENESIS
  • Primordial germ cell in embryoMitotic divisionsSpermatogonialstem cellMitotic divisionsSpermatogoniumMitotic divisionsPrimary spermatocyteMeiosis ISecondary spermatocyteMeiosis IIEarlyspermatidDifferentiation (Sertolicells provide nutrients)Sperm2n2n2nn nn n n nn n n nSPERMATO-GENESIS
  • Plasma membraneTailNeckMidpiece HeadMitochondriaNucleusAcrosomeSPERMATOZOAN STRUCTURE
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Oogenesis is development of matureoocytes (eggs) and can take many years• Eggs contain stored nutrients and aremuch larger.B. Oogenesis
  • OvaryPrimaryoocytewithinfollicleRupturedfollicleGrowingfollicleMature follicleOvulatedsecondary oocyteCorpus luteumDegeneratingcorpus luteumOOGENISIS
  • Fig. 46-12gPrimordial germ cellMitotic divisionsOogoniumMitotic divisionsPrimary oocyte(present at birth), arrestedin prophase of meiosis ICompletion of meiosis Iand onset of meiosis IISecondary oocyte,arrested at metaphase ofmeiosis IIFirstpolarbodyOvulation, sperm entryCompletion of meiosis IISecondpolarbodyFertilized egg2n2nnnnnIn embryoOOGENISIS
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings1. In oogenesis, one egg forms from eachcycle of meiosis; in spermatogenesis foursperm form from each cycle of meiosis.2. Oogenesis stops later in life in females;spermatogenesis continues throughout theadult life of males3. Oogenesis has long interruptions;spermatogenesis produces sperm fromprecursor cells in a continuous sequenceDifference between Spermatogenesisand oogenesis:
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings4. HORMONES INVOLVED IN HUMANREPRODUCTION• Human reproduction is coordinated byhormones from the:– hypothalamus (GnRH) ,– anterior pituitary (FSH and LH) , and– gonads
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsHYPOTHALAMUS• Gonadotropin-releasing hormone (GnRH) issecreted by the hypothalamus• and directs the release of FSH and LH fromthe anterior pituitary gland.• FSH and LH regulate processes in the gonadsand the production of sex hormones
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsAnterior pituitary gland• Release FSH and LH.• FSH (follicle stimulating hormone) and LHregulate processes in the gonads and theproduction of sex hormones.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Gonads produce and release thesex hormones.• Which include– androgens,– estrogens, and– progesteroneGonad hormones
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Sex hormones regulate:– The development of primary sexcharacteristics during embryogenesis.– The development of secondary sexcharacteristics at puberty– Sexual behavior and sex drive.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsa. Hormonal Control of the MaleReproductive System• FSH promotes the activity of Sertolicells, which nourish developingsperm and are located within theseminiferous tubules• LH regulates Leydig cells, whichsecrete testosterone and otherandrogen hormones, which in turnpromote spermatogenesis.Animation: Male HormonesAnimation: Male Hormones
  • HypothalamusGnRHFSHAnterior pituitarySertoli cells Leydig cellsInhibin Spermatogenesis TestosteroneTestisLHNegativefeedbackNegativefeedback– ––Hormonalcontrolof the testes
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Testosterone regulates the productionof GnRH, FSH, and LH throughnegative feedback mechanisms.• Sertoli cells secrete the hormoneinhibin, which reduces FSH secretionfrom the anterior pituitary.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsb. Hormonal control in Females andThe Reproductive Cycles of Females• Prior to ovulation, the endometriumthickens with blood vessels inpreparation for embryo implantation• If an embryo does not implant in theendometrium, the endometrium is shedin a process called menstruation.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Two cycles of female reproduction:– Changes in the uterus define themenstrual cycle (also called theuterine cycle)– Changes in the ovaries define theovarian cycle
  • Control by hypothalamus Inhibited by combination ofestradiol and progesteroneStimulated by high levelsof estradiolInhibited by low levels ofestradiolHypothalamusGnRHAnterior pituitaryFSH LHPituitary gonadotropinsin bloodLHFSHFSH and LH stimulatefollicle to growLH surge triggersovulationOvarian cycleGrowing follicle MaturingfollicleCorpusluteumDegeneratingcorpus luteumFollicular phase Ovulation Luteal phase(a)(b)(c)Days0 5 10 14 15 20 25 28| | | | | | | |––+
  • Ovarian hormonesin bloodPeak causesLH surgeEstradiol levelvery lowEstradiol ProgesteroneOvulation Progesterone and estra-diol promote thickeningof endometriumUterine (menstrual) cycleEndometrium0 5 10 14 20 25 28| | | | | | | |Days15Menstrual flow phase Proliferative phase Secretory phase(d)(e)
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsi. The Ovarian Cycle• The release of GnRH then FSH and LHstimulates follicle growth.• Follicle growth and an increase in thehormone estradiol characterize the follicularphase of the ovarian cycle.• The follicular phase ends at ovulation, and thesecondary oocyte is released.Animation: OvulationAnimation: Ovulation
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• The follicular tissue left behind forms thecorpus luteum; this is the luteal phase• The corpus luteum disintegrates, and ovarianLH and FSH decrease.Animation: Post OvulationAnimation: Post Ovulation
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummingsii. The Uterine (Menstrual) Cycle• Hormones coordinate the uterine cycle withthe ovarian cycle.• A new cycle begins if no embryo implants inthe endometrium.• Cells of the uterine lining can sometimesmigrate to an abnormal, or ectopic, location.• Swelling of these cells in response to hormonestimulation results in a disorder calledendometriosis.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings5. Menopause• After about 500 cycles, human females undergomenopause, the cessation of ovulation andmenstruation.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings6. Conception, Embryonic Development,and Birth• An egg develops into an embryo in a seriesof predictable events1.Conception• fertilization of an egg by a sperm, occursin the oviduct• The resulting zygote begins to divide bymitosis in a process called cleavage.• This gives rise to a blastocyst, a ball ofcells with a cavity.
  • OvaryUterusEndometrium(a) From ovulation to implantation(b) Implantation of blastocystCleavageFertilizationOvulationCleavagecontinuesThe blastocystimplantsTrophoblastInner cell massCavityBlastocystEndo-metrium12345Formation of the zygote and earlypost-fertilization events
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• After blastocyst formation, the embryo implantsinto the endometrium.• The embryo releases human chorionicgonadotropin (hCG), which preventsmenstruation.• Pregnancy, or gestation, is the condition ofcarrying one or more embryos in the uterus.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings7. Gestation: First Trimester• Human gestation can be divided intothree trimesters of about three monthseach.• The first trimester is the time of mostradical change for both the mother andthe embryo.• During implantation, the endometriumgrows over the blastocyst.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• During its first 2 to 4 weeks, the embryoobtains nutrients directly from theendometrium.• Meanwhile, the outer layer of the blastocyst,called the trophoblast, mingles with theendometrium and eventually forms theplacenta• Blood from the embryo travels to the placentathrough arteries of the umbilical cord andreturns via the umbilical vein
  • Fig. 46-16PlacentaUterusUmbilical cordChorionic villus,containing fetalcapillariesMaternal bloodpoolsMaternalarteriesMaternalveinsMaternalportionof placentaFetal arterioleFetal venuleUmbilical cordFetalportion ofplacenta(chorion)UmbilicalarteriesUmbilicalveinPlacental circulation
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• TWINS:• Splitting of the embryo during the first month ofdevelopment results in genetically identicaltwins• Release and fertilization of two eggs results infraternal and genetically distinct twins.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• The first trimester is the main period oforganogenesis, development of thebody organs.• All the major structures are present by8 weeks, and the embryo is called afetus
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Changes occur in the mother:– Growth of the placenta– Stop ovulation and menstrualcycle– Breast enlargement– Nausea is also very common
  • Fig. 46-17(a) 5 weeks (b) 14 weeks (c) 20 weeks
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsGestation: Second Trimester• During the second trimester:– The fetus grows and is very active– The mother may feel fetalmovements– The uterus grows enough for thepregnancy to become obvious.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsGestation: Third Trimester• During the third trimester, the fetusgrows and fills the space within theembryonic membranes• Hormones e.g. oxytocin induces andregulates labour, the process by whichchildbirth occurs
  • Fig. 46-18Estradiol OxytocinfromovariesInduces oxytocinreceptors on uterusfrom fetusand mother’sposterior pituitaryStimulates uterusto contractStimulatesplacenta to makeProstaglandinsStimulate morecontractionsof uterusPositivefeedback++A model for the induction oflabour
  • Fig. 46-19-1PlacentaUmbilical cordUterusCervixDilation of the cervix1The three stages of labour
  • Fig. 46-19-2Expulsion: delivery of the infant2
  • Fig. 46-19-3Delivery of the placentaUterusPlacenta(detaching)Umbilicalcord3
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings• Birth is brought about by a series ofstrong, rhythmic uterine contractions.• First the baby is delivered, and thenthe placenta.• Lactation, the production of milk, isunique to mammals.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings8. Contraception and Abortion• Contraception, the deliberate prevention ofpregnancy.• Contraceptive methods fall into threecategories:1. Preventing release of eggs and sperm2. Keeping sperm and egg apart3. Preventing implantation of an embryo
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsI. The rhythm method, or natural familyplanning, is to refrain from intercourse whenconception is most likely; it has a pregnancyrate of 10–20%.II. Coitus interruptus, the withdrawal of thepenis before ejaculation, is unreliable.III. Barrier methods block fertilization with apregnancy rate of less than 10%I. A condom fits over the penisII. A diaphragm is inserted into the vaginabefore intercourse.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsXV. Intrauterine devices are inserted into theuterus and interfere with fertilization andimplantation; the pregnancy rate is less than1%V. Female birth control pills are hormonalcontraceptives with a pregnancy rate of lessthan 1%
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsVI. Sterilization is permanent and prevents therelease of gametes:– Tubal ligation ties off the oviducts.– Vasectomy ties off the vas deferens.VII. Abortion is the termination of a pregnancy.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings9. Modern Reproductive Technologies• Ways of detecting Disorders During Pregnancy:a. Amniocentesis and chorionic villussampling are invasive techniques in whichamniotic fluid or fetal cells are obtained forgenetic analysis.b. Noninvasive procedures usually useultrasound imaging to detect fetal conditionc. Genetic testing of the fetus poses ethicalquestions and can present parents with difficultdecisions.
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings10. Treating Infertility• Modern technology can provide infertile coupleswith assisted reproductive technologies:– In vitro fertilization (IVF) mixes eggs withsperm in culture dishes and returns theembryo to the uterus at the 8 cell stage– Sperm are injected directly into an egg in atype of IVF called intracytoplasmic sperminjection (ICSI)
  • Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsVideo: Ultrasound of Human Fetus 1Video: Ultrasound of Human Fetus 1Video: Ultrasound of Human Fetus 2Video: Ultrasound of Human Fetus 2