扬州大学：《组织胚胎学》课程教学课件（讲稿）胚胎学总论 General Embryology

Chapter 21Generalembryology

Chapter 21 General embryology

Gametogenesis2Fertilizationto Implantation3BilaminarGerm DiscTrilaminarGermDisc4DifferentiationofGermLayers?6EstablishmentofBodyForm7.FetalMembranesandPlacenta8.Twins

1. Gametogenesis 2. Fertilization to Implantation 3. Bilaminar Germ Disc 4. Trilaminar Germ Disc 5. Differentiation of Germ Layers 6. Establishment of Body Form 7. Fetal Membranes and Placenta 8. Twins

1.GametogenesisA process offormationand maturation of thegametes (sperm and ovum)1.1Thepurposeof gametogenesisReductionof the numberof chromosomes.>Alteration of the shape of germ cells forfertilization

A process of formation and maturation of the gametes (sperm and ovum) 1.1 The purpose of gametogenesis  Reduction of the number of chromosomes.  Alteration of the shape of germ cells for fertilization. 1. Gametogenesis

1.2ProcessOogenesisSpermatogenesisOogoniumSpermatogoniummitosisfetal periodmitosispubertyPrimary spermatocytePrimaryoocytemeiosis 1pubertymeiosis1Secondaryoocyte-Secondaryspermatocytefertilizationmeiosis2meiosis2(22+X)K22+Y)QQQMatureovumPolarbodiesSpermatids(22 + X)(22 + X)

1.2 Process Spermatogenesis Oogenesis

Spermatogenesisa.ProcesspubertySpermatogoniumSpermatocyteSpermatids→Sperms-2n:46,xy2n:46,xyn:23 x;23n:23 x;23 ymitosismeiosisb. Functional mature:Get the ability of the movementc. Capacitating: Obtaining capacity of the fertilization

Spermatogenesis a. Process Spermatogonium Spermatocyte Spermatids Sperms mitosis meiosis 2n:46,xy 2n:46,xy n:23 x;23 y n:23 x;23 y b. Functional mature: Get the ability of the movement c. Capacitating: Obtaining capacity of the fertilization puberty

OogenesisOogoniumPrimaryOocyte-→SecondaryOocyte-→Ovum2n:46,xx2n:46,xxn:23 xn:23 xmeiosismitosis(fetal)(puberty)(fertilization)

Oogonium Primary Oocyte Ovum mitosis meiosis 2n:46,xx 2n:46,xx n:23 x n:23 x Oogenesis Secondary Oocyte (fetal) (puberty) (fertilization)

DifferencesbetweenmeleandfemaleMaleFemaleHasstemcellsNostemcellsContinuousafterpubertyPausetwice4spermfromaspermatocyteOnly1ovumfromanoocyteEqual divisionUnequal divisionNoFunctionalmatureandcapacitation

Differences between mele and female Male Female •Has stem cells No stem cells •Continuous after puberty Pause twice •4 sperm from a spermatocyte Only 1 ovum from an oocyte •Equal division Unequal division •Functional mature and No capacitation

1.3 Functional mature and capacitationofspermFunctional mature: geting ability of forwardmovement and potential of fertilizing eggs in theepididymisCapacitation: obtaining capacity of fertilizing anegg in the female reproductive tract throughremoval ofaglycoproteincoatfromtheplasmamembrane of the acrosomal region by enzyme(b-amylase)

• Functional mature: geting ability of forward movement and potential of fertilizing eggs in the epididymis • Capacitation: obtaining capacity of fertilizing an egg in the female reproductive tract through removal of a glycoprotein coat from the plasma membrane of the acrosomal region by enzyme (b-amylase). 1.3 Functional mature and capacitation of sperm

2. Fertilization to lmplantation(1st Week)an2.1Fertilizationandn--union of a spermoocyte to form a fertilized egg (zygote)2.1.1 Time: 12 - 24 hours after ovulation2.1.2 Site: ampulla of uterine tube.Corpus luteum12-24.hoursGraafianfollicleMyometrium-PerimetriumFimbriaEndometrium(progestationalstage)

2. Fertilization to Implantation (1st Week) 2.1 Fertilization - union of a sperm and an oocyte to form a fertilized egg (zygote) 2.1.1 Time: 12 - 24 hours after ovulation. 2.1.2 Site: ampulla of uterine tube

2.1.3 Process

2.1.3 Process