《人體胚胎學(xué)》教學(xué)課件PPT

1、人體胚胎學(xué)20 Preface1.Definition:(定義)Study development and mechanism of human body from fertilization to birth.2. Content(內(nèi)容)(1) Normal human body development in uterus.(胚胎發(fā)育)(2)Relation between mother and embryo.(母子關(guān)系)(3) Hereditary malformation and reproductive engineering(先天畸形與生殖工程) 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(胎兒期) 9Wbirth *perinatal period(圍產(chǎn)期) 26W-4W after birth 受精8周末 胚期 胎期 圍產(chǎn)期 （ 1-8周） （9-38周） (26周-生后4周)出生 受精、卵裂、 器官系統(tǒng)發(fā)育、 胚泡形成、 功能建立完善、 植入 、 胚體長(zhǎng)大。 三胚層形成分化、 胎膜胎盤形成 器官原基建立有害因素影響可致畸4、Im

3、portance and method (1) Importance (2) Study methods21 Human embryogenesis and development of early period1 Germ cell and fertilization(生殖細(xì)胞和受精)(1) Germ cell (生殖細(xì)胞) spermatozoon （精子）A. Morphological maturation(形態(tài)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 （輸卵管） C. Capacitation：獲能： Definition :It is defined as the final step of sperm maturation , consisting primarily of changes in the acrosome (頂體）that prepare it to release the enzymes required to penetrate the zona pellucida（透明帶）.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(卵細(xì)胞的發(fā)生） is discontinuous and begins during fetal life.B.The secondary oocyte is arrested at the second meiotic （減數(shù)分裂） meta

6、phase（中期） in ovulationC. Corona radiata（放射冠） and zona pellucida（透明帶） accompanied oocyteD. Oocyte survive :1day Capacity of fertilization :12hours（2）受精 fertilizationA. Definition(定義): It is a process that the spermatozoon（精子） successfully. penetrates the oocyte （卵母細(xì)胞）and forms zygote(受精卵） B.Position(

7、位置):the ampulla of the oviduct( 輸卵管壺腹部) C. Time(時(shí)間):within 12 hours after ovulation(排卵)or 24 hours after ejaculation(射精)D. 條件（1 ）精卵正常（2 ）精液質(zhì)量 3-5ml 次，400萬(wàn)個(gè)ml,畸形20%,30min 內(nèi)液化，活動(dòng)率 60%（1小時(shí)）。（3 ）精子獲能,卵子在第二次成熟分裂的中期（4 ）如期相遇（5 ）生殖道暢通（6 ）內(nèi)環(huán)境正常 A 內(nèi)分泌 B 抗精子抗體 C精神狀態(tài)E.The process of fertilization受精過(guò)程 Sperm bind

8、s in a human-specific interaction with a zp3(精卵識(shí)別)Acrosome reaction(頂體反應(yīng)):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.(兩膜融合) Zona reaction(透明帶反應(yīng)):Cortical granules release into the periv

9、itelline（卵黃周的） 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(兩性原核形成)Two pronuclei membranes disappear as both maternal and paternal chromosomes are replicated in pr

10、eparation for the first cleavage.(兩核融合)F. Significance of fertilization (受精的意義)（1 ）Form a new life (形成新個(gè)體)（2 ）Resume 2N quantity of DNA(染色體復(fù)常)（3 ）Decide sex(決定性別)TDF and SRY1980年代中期,發(fā)現(xiàn)了核型為46,XX的男性,但其X染色體上有很小一段Y染色體短臂上轉(zhuǎn)移來(lái)的片段.因此1990年揭示了這一片段上存在性別決定區(qū)域（sex determination region of Y chromosome ,SRY)。目前發(fā)現(xiàn)包括

11、至少6個(gè)基因參與了胚胎的性別決定。表達(dá)產(chǎn)物為TDF（testis determination factor) （4 ）Heredity and variation(遺傳與變異)2.Blastocyst formed and implantation(胚泡形成與植入）(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細(xì)胞時(shí)叫做桑葚胚The segregation of blastomeres into embryoblast and trophoblast precursors occurs in the morula. 二、卵裂cleavage（一）定義 卵裂球 blastomere （二）特點(diǎn)1 在透明帶內(nèi) 桑椹胚morula2 全能性3 不同步4 向?qū)m腔運(yùn)行途中 Blastomere morula(3)胚泡（blastocyst）The morula develops a fluid-filled cavity and is transformed into a

14、blastocyst胚端滋養(yǎng)層Polar trophoblast內(nèi)細(xì)胞群inner cell mass胚泡腔blastocoele滋養(yǎng)層trophoblast (4)植入implantationA. Definition:B.Time:5-6 day to 11-12day C.condition (條件)1胚泡發(fā)育與子宮內(nèi)膜同步2 透明帶準(zhǔn)時(shí)脫落3宮腔的正常內(nèi)環(huán)境4 母體內(nèi)分泌正常D.ProcessThe blastocyst hatches from the zona pellucida before implantingE.位置 子宮底和體,最多見后壁的中上份F.異常植入 宮外孕 前置胎

15、盤3、植入后的變化（一）子宮內(nèi)膜的變化 蛻膜 decidua蛻膜反應(yīng) decidual response（二）分部基蛻膜decidua basalis包蛻膜decidua capsularis壁蛻膜decidua parietalis4.Clinical applications(1)Chromosomal abnormalities result in spontaneous abortion or abnormal development It is estimated that one third of all conceptions （孕體）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受精與節(jié)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.