1. 组织胚胎学课件组织胚胎学课件 中国医科大学 基础医学院 组胚 — 英文教学组

2. HUMAN HUMANEMBRYOLOGY Department of Histology and Embryology China Medical University China Medical University

3. Chapter 4 Further Development of Embryo Chapter 4 Further Development of Embryo

4. Formation and differentiation of trilaminar germ disc

5. 1. formation of epiblast and hypoblast : By the 8th day, the inner cell mass differentiates into two layers of cells 1. formation of epiblast and hypoblast : By the 8th day, the inner cell mass differentiates into two layers of cells epiblast (columnar) hypoblast (cuboidal) bilaminar germ disc

6. Amnionic cavity epiblast hypoblast Bilaminar germ disc

7. ---epiblast: primary ectoderm amniotic cavity: amniotic fluid roof: amniogenic cells floor: epiblast ---epiblast: primary ectoderm amniotic cavity: amniotic fluid roof: amniogenic cells floor: epiblast

8. --- hypoblast: primary endoderm hypoblast →Heuser’s membrane →primary yolk sac --- hypoblast: primary endoderm hypoblast →Heuser’s membrane →primary yolk sac

9. Amnionic cavity epiblast hypoblast Bilaminar germ disc Extra-embryonic mesoderm Primary yolk sac

10. Body stalk Extra-embryonic cavity Extra-embryonic mesoderm Primary yolk sac secondary yolk sac

11. extra-embryonic mesoderm → extra-embryonic cavity (chorionic cavity) --visceral layer --parietal layer /secondary yolk sac: yolk sac ---body stalk (connecting stalk): formed by extra-embryonic mesoderm extra-embryonic mesoderm → extra-embryonic cavity (chorionic cavity) --visceral layer --parietal layer /secondary yolk sac: yolk sac ---body stalk (connecting stalk): formed by extra-embryonic mesoderm

12. 2. formation of mesoderm: in the early of the 3rd week ---primitive streak: cells of epiblast proliferate to form a longitudinal arranged cell cord * determination of head and tail of germ disc 2. formation of mesoderm: in the early of the 3rd week ---primitive streak: cells of epiblast proliferate to form a longitudinal arranged cell cord * determination of head and tail of germ disc

13. 2. formation of mesoderm: in the early of the 3rd week ---primitive streak ---primitive node ( primitive knot ) 2. formation of mesoderm: in the early of the 3rd week ---primitive streak ---primitive node ( primitive knot )

14. 2. formation of mesoderm: in the early of the 3rd week ---primitive streak: ---primitive node ( primitive knot ) ---primitive pit (blastopore) 2. formation of mesoderm: in the early of the 3rd week ---primitive streak: ---primitive node ( primitive knot ) ---primitive pit (blastopore)

16. ---mesoderm: intra-embryonic mesoderm ---endoderm: hypoblast cells are replaced by epiblast cells ---ectoderm: epiblast changed the name into ectoderm ---mesoderm: intra-embryonic mesoderm ---endoderm: hypoblast cells are replaced by epiblast cells ---ectoderm: epiblast changed the name into ectoderm

17. by the end of the 3rd week trilaminar germ disc: endoderm + mesoderm + ectoderm by the end of the 3rd week trilaminar germ disc: endoderm + mesoderm + ectoderm

18. ---head process→notochordal tube → notochord ---buccopharyngeal membrane ---cloacal membrane ---head process→notochordal tube → notochord ---buccopharyngeal membrane ---cloacal membrane notochord

19. 3. differentiation of trilaminar germ disc 4 th –8 th weeks ---differentiation: same cells which are primordial and inmuture differentiate into different cells which have specific structure and function ---induction: some tissues effect the differentiation, and determine the differentiating orientation of another tissue 3. differentiation of trilaminar germ disc 4 th –8 th weeks ---differentiation: same cells which are primordial and inmuture differentiate into different cells which have specific structure and function ---induction: some tissues effect the differentiation, and determine the differentiating orientation of another tissue

20. (1) differentiation of ectoderm: from 18 th –19 th days ---neural plate: neuro-epithelium (neural ectoderm): pseudostratified columnar epi. (1) differentiation of ectoderm: from 18 th –19 th days ---neural plate: neuro-epithelium (neural ectoderm): pseudostratified columnar epi. neural plate Notochord

21. (1) differentiation of ectoderm: from 18 th –19 th days ---neural plate ---neural groove ---neural fold (1) differentiation of ectoderm: from 18 th –19 th days ---neural plate ---neural groove ---neural fold Neural groove Notochord

22. Neural tube Anterior and posterior neuropores ---neural tube: →CNS /anterior neuropore: closed by 25th days /posterior neuropore: closed by 27th days

23. anencephaly Spina bifida

24. ---neural tube: CNS ---neural crest: two lines of cell cords→ganglions

25. (2)differentiation of mesoderm: 17 th day Neural groove Intermediate mesoderm Lateral mesoderm paraxial Mesoderm endoderm

26. ---paraxial mesoderm somite: 20 th days, 3 pairs/per day, 42- 44 pairs by the end of 5 th weeks -sclerotome: →bone, cartilage -dermatome: → dermis and hypodermis -myotome: →skeletal muscle ---paraxial mesoderm somite: 20 th days, 3 pairs/per day, 42- 44 pairs by the end of 5 th weeks -sclerotome: →bone, cartilage -dermatome: → dermis and hypodermis -myotome: →skeletal muscle

27. Intermediate mesoderm Neural canal Somite endoderm Intraembryonic cavity

28. --- intermediate mesoderm: →kidney and reproductive system --- intermediate mesoderm: →kidney and reproductive system

29. ---lateral mesoderm: Intra-embryonic coelom: →body cavity parietal or somatic mesoderm: →muscle, CT, parietal layer of pleura, peritoneum and pericardium visceral or splanchnic mesoderm: →muscle, CT of digestive tract, visceral layer of pleura, peritoneum and pericardium ---lateral mesoderm: Intra-embryonic coelom: →body cavity parietal or somatic mesoderm: →muscle, CT, parietal layer of pleura, peritoneum and pericardium visceral or splanchnic mesoderm: →muscle, CT of digestive tract, visceral layer of pleura, peritoneum and pericardium

30. Parietal mesoderm visceral mesoderm Intra-embryonic cavity

31. 3. differentiation of endoderm: primitive gut: →digestive, respiratory and urinary system 3. differentiation of endoderm: primitive gut: →digestive, respiratory and urinary system foregut midgut hindgut Cloacal membrane oropharyngeal membrane

33. 1. Embryonic period is 1. Embryonic period is A. from fertilization to the end of week 2 A. from fertilization to the end of week 2 B. from fertilization to the end of week 8 B. from fertilization to the end of week 8 C. from week 3 to the end of week 8 C. from week 3 to the end of week 8 D. from week 5 to the end of week 8 D. from week 5 to the end of week 8 E. from week 9 until birth E. from week 9 until birth 2. How long will an individual stay in the uterus of its mother? mother? A. 18 weeks A. 18 weeks B. 28 weeks B. 28 weeks C. 38 weeks C. 38 weeks D. 48 weeks D. 48 weeks E. 58 weeks E. 58 weeksB C

34. 3. What is penetrated by a spermatozoon during the process of fertilization process of fertilization A. oogonium A. oogonium B. primary oocyte B. primary oocyte C. secondary oocyte C. secondary oocyte D. primary follicle D. primary follicle E. primordial follicle E. primordial follicle 4. Which protein is receptor of spermatozoa on the zona pellucida? pellucida? A. ZP1 B. ZP2 A. ZP1 B. ZP2 C. ZP3 D. ZP4 C. ZP3 D. ZP4 E. ZP5 E. ZP5 C C

35. 5. The time of implantation is 5. The time of implantation is A. from 1st-2nd day to 7th-8th day A. from 1st-2nd day to 7th-8th day B. from 3rd-4th day to 9th-10th day B. from 3rd-4th day to 9th-10th day C. from 5th-6th day to 11th-12th day C. from 5th-6th day to 11th-12th day D. from 7th-8th day to 13th-14th day D. from 7th-8th day to 13th-14th day E. from 9th-10th day to 15th-16th day E. from 9th-10th day to 15th-16th day 6. Which structure is not belong to early blastocyst ? 6. Which structure is not belong to early blastocyst ? A. trophoblast A. trophoblast B. zona pellucida B. zona pellucida C. inner cell mass C. inner cell mass D. blastocoele D. blastocoele E. endoderm E. endodermC E

36. 7. Which is not correct about implantation 7. Which is not correct about implantation A. blastocyst will be imbedded in the endomytrium A. blastocyst will be imbedded in the endomytrium B. zona pellucida disappears B. zona pellucida disappears C. polar trophoblast secretes proteinase C. polar trophoblast secretes proteinase D. endomytrium is in proliferative phase D. endomytrium is in proliferative phase E. there is a corpus luteum of pregnancy in the ovary E. there is a corpus luteum of pregnancy in the ovary 8. The most common position of implantation is 8. The most common position of implantation is A. mucus of uterine tube A. mucus of uterine tube B. mucus of ampullary portion of uterine tube B. mucus of ampullary portion of uterine tube C. ovary C. ovary D. mucus of cervix of uteru D. mucus of cervix of uteru E. mucus of body of uterus E. mucus of body of uterusD E

37. Question s 1. Describe the formation of bilaminar germ disc and its associated structures. associated structures. 2. Describe the formation of trilaminar germ disc and its associated structures. associated structures. 3. Describe the differentiation of three germ layers briefly. 4. Preview fetal membrane and placenta. Chapter 4 Further Development of Embryo Chapter 4 Further Development of Embryo