《人体胚胎学》教学课件PPT

1、人体胚胎学20 Preface1.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)preembr

2、yonic period(胚前期) fertilization to 2W (2)embryonic period(胚期) 3W8W (sensitive period of teratogenesis,致畸敏感期) (3)fetal period(胎儿期) 9Wbirth *perinatal period(围产期) 26W-4W 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、Im

3、portance and method (1) Importance (2) Study methods21 Human embryogenesis and development of early period1 Germ cell and fertilization(生殖细胞和受精)(1) Germ cell (生殖细胞) spermatozoon （精子）A. Morphological maturation(形态的成熟) in testisB.Spermatozoa undergo a Functional maturation in process of journey from t

4、he seminiferous tubules （生精小管） to the ampulla of the oviduct （输卵管） C. Capacitation：获能： Definition :It is defined as the final step of sperm maturation , consisting primarily of changes in the acrosome (顶体）that prepare it to release the enzymes required to penetrate the zona pellucida（透明带）.Position :

5、within female genital tract （女性生殖管道）and to require contact with the secretions of the oviduct .Sperm survive :13 dayCapacity of fertilization :1dayOvum (卵子):CharacterA.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） meta

6、phase（中期） in ovulationC. Corona radiata（放射冠） and zona pellucida（透明带） accompanied oocyteD. Oocyte survive :1day Capacity of fertilization :12hours（2）受精 fertilizationA. 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(

7、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 3-5ml 次，400万个ml,畸形20%,30min 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 bind

8、s 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 periv

9、itelline（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 pr

10、eparation 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 SRY1980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

11、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 a

12、ccompanied by cell growth, so the subdivide the large zygote into many smaller daughter cells called blastomeres（卵裂球）. 24hours 2 blastomeres 40hours 4 blstomeres3days 612cells4days 16-32cells(2)Morula（桑葚胚） : by the 32 cell stage, the embryo has the appearance of a small mulberry and is therefore,cal

13、led 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morula2 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

14、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implantationA. 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.ProcessThe blastocyst hatches from the zona pellucida before implantingE.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

15、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 parietalis4.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 wom

16、en 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.CauseMany chromosomal anomalies arise during gametogenesi

17、s and cleavageDown syndrome is an example of a disorder caused by an error during meiosis or mitosisChromosome 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

18、 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.