【医学生物】组织胚胎学课件9

,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,组织胚胎学课件,中国医科大学,基础医学院,组胚,英文教学组,1,业精于勤荒于嬉 行成于思毁于随 【医学生物PPT，欢迎收藏分享】豆丁网友,组织胚胎学课件中国医科大学1 业精于勤荒于嬉 行成于思毁,HUMAN,EMBRYOLOGY,Department of Histology and Embryology,China Medical University,HUMAN,Chapter 3,First Week of Development:,Ovulation to Implantation,Chapter 3,Ovarian Cycle,At puberty,the female begins to undergo regular,monthly cycles.,These sexual cycles are controlled by the HPG,(Hypothalamus-Pituitary-Gonad)axis.,GnRH,Gonadotropin,follicle-stimulating hormone(FSH),luteinizing hormone(LH)/ICSH,Ovarian Cycle At puberty,the,At the beginning of each ovarian cycle,15 to 20 primary(preantral)follicles are stimulated to grow under the influence of FSH.,Under normal conditions,only one of these follicles reaches full maturity,and only one oocyte is discharged;the others degenerate and become atretic.,When a follicle becomes atretic,the oocyte and surrounding follicular cells degenerate and are replaced by connective tissue,forming the interstitial gland(corpus atreticum).,At the beginning of each ovar,Granulosa and thecal cells produce estrogens that(,a,)cause the uterine endometrium to enter the follicular or proliferative phase;,(,b,)cause thinning of the cervical mucus to allow passage of sperm;,(,c,)stimulate the pituitary gland to secrete LH.,Granulosa and thecal cells pr,At mid-cycle,there is an LH surge that,(,a,)causes oocytes to complete meiosis I and initiate meiosis II;,(,b,)stimulates production of progesterone by follicular stromal cells(luteinization);,(,c,)causes follicular rupture and ovulation.,At mid-cycle,there is an LH s,Ovulation,Ovulation,The process that the mature follicle ruptures and the secondary oocyte,zona pellucida,corona radiata and follicular fluid are released from the ovary is called,.,Time,:,ovulation takes place at about the,middle of the cycle,.,Ovulation,The process that the mature fo,【医学生物】组织胚胎学课件9,The fate of the secondary oocyte,after ovulation,Degeneration undergoes if no fertilization occurs.,If fertilization happens,，,the second meiosis is finished,and the ovum forms.,The fate of the secondary oocy,FATE 1,FATE 2,FATE 1FATE 2,After ovulation,granulosa cells remaining in the wall of the ruptured follicle,together with cells from the theca interna,are vascularized by surrounding vessels.Under the influence of LH,these cells develop a yellowish pigment and change into,luteal cells,which form the,corpus luteum,Corpus Luteum,After ovulation,granulosa cel,GRANULOSA LUTEIN CELLS,THECA LUTEIN CELLS,GRANULOSA LUTEIN CELLSTHECA LU,Cells of corpus luteum,Granulosa lutein C,：,progesterone and relaxin,Theca lutein C,：,estrogen,Progesterone,together with estrogen,causes the uterine mucosa to enter the,progestational,or,secretory stage,in preparation for implantation of the embryo.,Cells of corpus luteumProgest,Fate of corpus luteum,Corpus luteum of menstruation,corpus albicans,Corpus luteum of pregnancy,corpus albicans,Fate of corpus luteum,Corpus albicans,Corpus albicans,Relation of fimbriae and ovary.Fimbriae collect the oocyte and sweep it into the uterine tube.,Relation of fimbriae and ovary,Fertilization,-,Fertilization,is the process in which the male and female gametes(sperm and ovum)unite to give rise to a zygote.,-place:in the ampulla of the uterine tube,Fertilization-Fertilization,Conditions of fertilization:,1)maturation of oocyte,2)maturation of spermatozoa:,2-3 weeks in the ductus epididymis,acquire some motility,Conditions of fertilization:,decapacitation factor,:exist in epididymis,to inhibit the release of acrosome enzymes,capacitation factor,:secreted by epi.cells of oviduct,capacity of releasing acrosome enzymes,capacitation of spermatozoa,decapacitation factor:exist i,3,)quality and quantity of spermatozoa:,normal:3-4 ml,100,000,000/ml,abnormal:,1.5 ml;or 30%;,mobility 70%,4)meeting of sperm and ovum,sperm:4 days ovum:2 days,3)quality and quantity of spe,processes of fertilization:,1),acrosome reaction,:,A.,hyaluronic acidase:dissolve corona radiata,B.interact with ZP3(receptor glycoprotein,exist in,zona pellucida)molecules,release acrosin:,dissolve zona pellucida,then some spermatozoa enter perivitelline space,processes of fertilization:,2)only one spermatozoon fuse with membrane of the ovum,:,nucleus enter cytoplasm of the ovum,cortical reaction,:cortical granules(located in cytoplasm of ovum)are released into perivitelline space,and cause,zona reaction,:change of ZP3 molecules in zona pellucide,2)only one spermatozoon fu,3)formation of zygote,(fertilized ovum),A.secondary meiosis complete:,form second polar body,B.male pronucleus fuse with female,pronucleus to restore 2N chromosomes,3)formation of zygote(fertil,【医学生物】组织胚胎学课件9,significance of fertilization,:,1)a new life begin(initiation of cleavage),2)restoration of the diploid number of,chromosomes,3)determination of the sex of the new,individual:,ovum(22+X)+X-bearing spermatozoon=girl,ovum(22+X)+Y-bearing spermatozoon=boy,significance of fertilization:,Blastocyst format