组培人体胚胎学.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,人体胚胎学,Human embryology,主讲人：苏衍萍,20 Preface,1.,Definition:(,定义,),Study development and mechanism of human body from fertilization to birth.,2.,Content(,内容,),(1),Normal human body development in uterus.(,胚胎发育,),(2),Relation between mother and embryo.,(,母子关系,)3),Hereditary malformation and reproductive engineering(,先天畸形与生殖工程,),3,、,胚胎分期,(,1),preembryonic period,(,胚前期,),fertilization to 2W,(,2),embryonic period,(,胚期),3W,8,W,(,sensitive period,of teratogenesis,致畸敏感期),(,3),fetal period,(,胎儿期),9,Wbirth,*,perinatal period,(,围产期),26,W-,4,W after birth,受精,8周末,胚期 胎期 围产期,（1-8周）（9-38周）,(26周-生后4周),出生,受精、卵裂、器官系统发育、,胚泡形成、功能建立完善、,植入、胚体长大。,三胚层形成分化、,胎膜胎盘形成,器官原基建立,有害因素影响可致畸,4、,Importance and method,(,1),Importance,(2),Study methods,Ovum,(卵子,):,Character,A.Oogenesis(,卵细胞的发生）,is discontinuous and begins during fetal life.,B.The secondary oocyte is arrested at the second meiotic（,减数分裂）,metaphase（,中期）,in ovulation,C.Corona radiata（,放射冠）,and zona pellucida（,透明带）,accompanied oocyte,D.Oocyte survive:1day,Capacity of fertilization:12hours,（2）受精,fertilization,A.Definition(,定义,):,It is a process that the spermatozoon（,精子）,successfully,.,penetrates the oocyte（,卵母细胞）,and forms zygote(,受精卵）,B.Position(,位置,):the ampulla of the oviduct(,输卵管壶腹部),C.Time(,时间,):within 12 hours after ovulation(,排卵),or 24 hours after ejaculation(,射精),D.,条件,（1）,精卵正常,（2）,精液质量,3-5,ml,次，400万个,ml,畸形20%,30,min,内液化，活动率 60%（1小时）。,（3）,精子获能,卵子在第二次成熟分裂的中期,（4）,如期相遇,（5）,生殖道畅通,（6）,内环境正常,A,内分泌,B,抗精子抗体,C,精神状态,E.The process of fertilization,受精过程,Sperm binds in a human-specific,interaction with a zp3(,精卵识别),Acrosome reaction(,顶体反应),:The acrosome is induced to release degradative(,降解,),enzymes that allow the sperm to penetrate,（,穿透）,the zona pellucida.,The cell membranes of the,two cells fuse.(,两膜融合),Zona reaction(,透明带反应),:,Cortical granules release into the perivitelline（,卵黄周的）,space and interact with the zona pellucida.It alters the sperm receptor molecules,causing the zona to become impenetrable by additional spermatozoa.,Female and male pronuclei formed(,两性原核形成),Two pronuclei membranes disappear,as both maternal and paternal chromosomes are replicated in preparation for the first cleavage.(,两核融合),F.,Significance of fertilization,(,受精的意义),（1）,Form a new life(,形成新个体),（2）,Resume 2N quantity of DNA(,染色体复常),（3）,Decide sex(,决定性别),TDF and SRY,1980,年代中期,发现了核型为,46,XX,的男性,但其,X,染色体上有很小一段,Y,染色体短臂上转移来的片段,.,因此,1990,年揭示了这一片段上存在性别决定区域（,sex,determination region of Y chromosome,SRY),。目前发现包括至少6个基因参与了胚胎的性别决定。表达产物为,TDF,（,testis determination factor),（4）,Heredity and variation(,遗传与变异),2.,Blastocyst formed and implantation(,胚泡形成与植入）,(1)Zygote cleavage（,卵裂）,Within 24 hours after fertilization,the zygote embarks on a regulated series of mitotic cell divisions called cleavage.The divisions are not accompanied by cell growth,so the subdivide the large zygote into many smaller daughter cells called,blastomeres（,卵裂球）.,24hours 2 blastomeres,40hours 4 blstomeres,3days 612cells,4days 16-32cells,(2)Morula（,桑葚胚）:,by the 32 cell stage,the embryo has the appearance of a small mulberry and is therefore,called a morula.,12-16,细胞时叫做桑葚胚,The segregation of blastomeres into embryoblast and trophoblast precursors occurs in the morula.,二、卵裂,cleavage,（,一）定义,卵裂球,blastomere,（,二）特点,1 在透明带内,桑椹胚,morula,2,全能性,3,不同步,4 向宫腔运行途中,Blastomere morula,(3),胚泡（,blastocyst,）,The morula develops a fluid-filled cavity and is transformed into a blastocyst,胚端滋养层,Polar trophoblast,内细胞群,inner cell mass,胚泡腔,blastocoele,滋养层,trophoblast,(4)植入,implantation,A.Definition:,B.Time:,5-6,day to 11-12day,C.condition(,条件),1,胚泡发育与子宫内膜同步,2 透明带准时脱落,3,宫腔的正常内环境,4,母体内分泌正常,D.Process,The blastocyst hatches from the zona pellucida before implanting,E.,位置,子宫底和体,最多见后壁的中上份,F.,异常植入,宫外孕,前置胎盘,3、植入后的变化,（一）子宫内膜的变化,蜕膜,decidua,蜕膜反应,decidual response,（二）分部,基蜕膜,decidua basalis,包蜕膜,decidua capsularis,壁蜕膜,decidua parietalis,4.,Clinical applications,(1)Chromosomal abnormalities result in spontaneous abortion or abnormal development,It is estimated that one third of all conceptions,（孕体）,in normal,healthy women abort spontaneously;approximately one fourth of these occur before pregnancy is detected.Chromosomal anomalies appear to cause about 40 to 50 percent of spontaneous abortions in cases on which the conceptus has been recovered and examined.,Cause,Many chromosomal anomalies arise during gametogenesis and cleavage,Down syndrome is an example of a disorder caused by an error during meiosis or mitosis,Chromosome analysis can determine the parental source and the defective chromosome and provides a basis for diagnosis an possible treatment,(2)Contraceptive techniques interfere with a wide variety of reproductive mechanisms,受精与节育和不孕不育,Despite the high rate of spontaneous abortion,human reproductive efficiency is very high.,Methods:,（,1,）,Barrier contraceptives prevent the sperm from reaching the egg.(2)The birth control pill prevent ovulation.(3)injected or implanted sources of progestin deliver a chronic antiovulatory dose.,（,(4)Nonmedicated IUDs may interfere with conception through effects on both sperm and egg.,(5)The antiprogesterone compound RU-486 is an abortifacient.,(6)sterilization is used by about one third of american couples.,(7)new methods of contraception are needed.,Infertile(15%-30%in American),The maturation of human gametes and early embryos can now be supported outside the body to assist infertile couples.,An oocyte can be fertilized in vitro and then implanted in the uterus.In vitro fertilization and embryo transfer(IVF).,Gametes or zygotes can be introduced directly into the ampulla of the oviduct.,See You,