1. Placenta and the mammary gland Rachel Boggus Boggusrl@email.uc.edu

2. 9/16/2015 Free Template from www.brainybetty.com 2 Orientation to development of the placenta What happens to the stratum functionalis after implantation? What are these responses called? What is the endometrium now called?

3. 9/16/2015 Free Template from www.brainybetty.com 3 Orientation to development of the placenta What happens to the stratum functionalis after implantation? –Cells enlarge and proliferate  decidual cells… synthesize prolactin and relaxin. Also becomes more highly vascularized What are these responses called? What is the endometrium now called? –Called decidual reaction, endometrium called decidua

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5. 9/16/2015 Free Template from www.brainybetty.com 5 Selective elaboration of the chorion What does it mean to say that implantation is interstitial? What is the chorion frondosum? What is the chorion laeve?

6. 9/16/2015 Free Template from www.brainybetty.com 6 Selective elaboration of the chorion What does it mean to say that implantation is interstitial? –Embryo completely embeds itself into maternal decidual tissue What is the chorion frondosum? –Disk shaped region of chorion that continues to develop What is the chorion laeve? –Regions of chorion near decidua capsularis that regress

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8. 9/16/2015 Free Template from www.brainybetty.com 8 Development of Embryonic Circulation Develops from intraembryonic mesenchyme within the fetus These vessels are connected to two umbilical arteries and one umbilical vein.

9. 9/16/2015 Free Template from www.brainybetty.com 9 What are the layers of the early placenta?

10. 9/16/2015 Free Template from www.brainybetty.com 10 What are the layers of the early placenta? 1)Epithelial layer of the amnion 2)Extraembryonic mesenchyme 3)Cytotrophoblast 4)Syncytiotrophoblast 5)Zone connecting villi and lacunae (intervillous space) 6)Syncytiotrophoblast 7)Maternal decidua

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12. 9/16/2015 Free Template from www.brainybetty.com 12 Placenta What is the chorionic plate?

13. 9/16/2015 Free Template from www.brainybetty.com 13 Placenta What is the chorionic plate? –Syncytiotrophoblast, cytotrophoblast and underlying extraembryonic reticulum

14. 9/16/2015 Free Template from www.brainybetty.com 14 Histology What are hofbauer cells? Where are they visualized? What are anchoring villi? What is the cytotrophoblastic shell?

15. 9/16/2015 Free Template from www.brainybetty.com 15 Histology What are hofbauer cells? –Fetal macrophages Where are they visualized? –Within mesenchyme of the villi What are anchoring villi? –Stem villi that extend across the intervillous space and connect with the decidual side

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18. 9/16/2015 Free Template from www.brainybetty.com 18 Red = chorionic plate; blue = stem villi If it reaches the other side it is an anchoring villi

19. 9/16/2015 Free Template from www.brainybetty.com 19 BASAL PLATE = Green arrows: anchoring villi; cytotrophoblasts: blue arrow Red Arrow: fibrinoid

20. 9/16/2015 Free Template from www.brainybetty.com 20 Placenta What is the maternal side of the placenta called? What is it composed of? What is fibrinoid?

21. 9/16/2015 Free Template from www.brainybetty.com 21 Placenta What is the maternal side of the placenta called? What is it composed of? –Basal plate, syncytiotrophoblast, cytotrophoblast shell, and decidual tissue What is fibrinoid? –Extravillous cytotrophoblast cells and maternal blood clots form this acidophilic extracellular matrix

22. 9/16/2015 Free Template from www.brainybetty.com 22 Basal plate between arrows

23. 9/16/2015 Free Template from www.brainybetty.com 23 Functions of syncytiotrophoblast What are cytotrophoblast cells like? What about the syncytiotrophoblasts? (hormones, appearance?) What maintains the corpus luteum?

24. 9/16/2015 Free Template from www.brainybetty.com 24 Functions of syncytiotrophoblast What are cytotrophoblast cells like? –Stem cells—cuboidal, dispersed chromatin, lack of elaborate organelles What about the syncytiotrophoblasts? (hormones, appearance?) –Very active cells—multinucleated, microvilli, numerous pinocytic vesicles. HCG, estrogen, progesterone and prolactin What maintains the corpus luteum? –HCG

25. 9/16/2015 Free Template from www.brainybetty.com 25 Red Arrow: cytotrophoblast Blue Arrows: Syncytiotrophoblast

26. 9/16/2015 Free Template from www.brainybetty.com 26 Maternal cotyledons What are they?

27. 9/16/2015 Free Template from www.brainybetty.com 27 Maternal cotyledons What are they? –Formed by placental septa –Composed of core of decidual tissue covered by cytotrophoblast and snycytiotrophoblast. –Do not reach the opposing chorionic plate

28. 9/16/2015 Free Template from www.brainybetty.com 28 Gas Exchange They love to ask questions about gas exchange so know this! Is there direct mixing of fetal and maternal blood? What are the layers that O2 must pass through initially?

29. 9/16/2015 Free Template from www.brainybetty.com 29 Gas Exchange They love to ask questions about gas exchange so know this! Is there direct mixing of fetal and maternal blood? NO What are the layers that O2 must pass through initially? 1.syncytiotrophoblast 2.cytotrophoblast 3.basement membrane cytotropho.. 4.extraembryonic mesenchyme 5.basement memb. Fetal endoth. 6.fetal endothelial cells

30. 9/16/2015 Free Template from www.brainybetty.com 30 What are the modifications as the placental matures? Clustering of the nuclei of syncytiotrophoblast  syncytial knots Cytotrophoblast cells cease division (eventually not a continuous layer) Fetal bld vessels move closer to syncytiotrophoblast layer (eventually basal lamina of syncyts. fuses with fetal endothelium basal lamina.)

31. 9/16/2015 Free Template from www.brainybetty.com 31 Syncytial knots (they LOVE these)

32. 9/16/2015 Free Template from www.brainybetty.com 32 Umbilical cord What does the core develop from? What does the mesenchyme form? What covers the outside of the cord? What does the mature umbilical cord consist of?

33. 9/16/2015 Free Template from www.brainybetty.com 33 Umbilical cord What does the core develop from? –Extraembryonic mesenchyme of connecting stalk What else does it form? –Umbilical vessels What covers the outside of the cord? –The expanding amniotic membrane What does the mature umbilical cord consist of? –Outer epithelial covering (amniotic memb.), inner mucus CT (wharton’s jelly), and umbilical vessels

34. 9/16/2015 Free Template from www.brainybetty.com 34 Two arteries, one vein

35. 9/16/2015 Free Template from www.brainybetty.com 35 Mammary Gland How many lactiferous ducts are in each breast? Remember that they each emerge as a separate opening What happens just under the epithelium? What happens to the epithelium?

36. 9/16/2015 Free Template from www.brainybetty.com 36 Mammary Gland How many lactiferous ducts are in each breast? 15-25 Remember that they each emerge as a separate opening What happens just under the epithelium? –They dilate to form lactiferous sinus What happens to the epithelium? –Strat squam at opening  strat columnar  strat, cuboidal  simple cuboidal with myoepithelial cells

37. 9/16/2015 Free Template from www.brainybetty.com 37 Alveolar system What are the milk components, how are they produced?

38. 9/16/2015 Free Template from www.brainybetty.com 38 Alveolar system What are the milk components, how are they produced? –Milk proteins synthesized by RER and secreted by exocytosis –Lipid droplets not membrane bound and are released within plasma memb. TRUE apocrine secretion –IgA moved by transcytosis  sIgA

39. 9/16/2015 Free Template from www.brainybetty.com 39 Lobes, lobules, and CT Remember that each lactiferous duct drains one lobe Lobes divided into lobules Within each lobule, intralobular CT is loose with lots of plasma cells which make the IgA Lots of adipose tissue surrounds the lobes

40. 9/16/2015 Free Template from www.brainybetty.com 40 Nipple and areola What is the epithelium? How is it different than the rest of the breast?

41. 9/16/2015 Free Template from www.brainybetty.com 41 Nipple and areola What is the epithelium? –Stratified squamous epithelium How is it different than the rest of the breast? –Longer dermal papilla

42. 9/16/2015 Free Template from www.brainybetty.com 42 Nipple; blue = smooth muscle; note large dermal papilla

43. 9/16/2015 Free Template from www.brainybetty.com 43 Mammary Gland Development Before puberty sparse duct system with little adipose tissue At puberty which hormones induce secondary sex characteristics in breasts? What are these changes?

44. 9/16/2015 Free Template from www.brainybetty.com 44 Mammary Gland Development Before puberty sparse duct system with little adipose tissue At puberty which hormones induce secondary sex characteristics in breasts? –Estrogen, progesterone, growth hormone, thyroid hormone, glucocorticoids What are these changes? –Inc. adipose, CT, and bld. Vessels, enlargement of areola

45. 9/16/2015 Free Template from www.brainybetty.com 45 Post-puberty Beginning of cycle—sparse glands and ducts. End—more elaborate and lumen apparent within alveoli Pregnancy—estrogen induces branching and progesterone cause alveolar development Towards the end of pregnancy secretory cells enlarge and distend with colostrum After birth produces milk rich in lipid SECRETORY cells eosinophilic with clear vacuoles from lipid droplet dissolution

46. 9/16/2015 Free Template from www.brainybetty.com 46 Immature breast

47. 9/16/2015 Free Template from www.brainybetty.com 47 Mammary gland of pregnant woman

48. 9/16/2015 Free Template from www.brainybetty.com 48 Lactating mammary gland – fat droplets IN CELLS

49. 9/16/2015 Free Template from www.brainybetty.com 49 Regressing mammary gland

50. 9/16/2015 Free Template from www.brainybetty.com 50 Hormones and milk production What happens to prolactin levels throughout pregnancy? What happens to estrogen and progesterone at birth? What happens with suckling?

51. 9/16/2015 Free Template from www.brainybetty.com 51 Hormones and milk production What happens to prolactin levels throughout pregnancy? –They gradually increase but the high levels of estrogen and progesterone inhibit milk production What happens to estrogen and progesterone at birth? –The levels fall and prolactin begins to induce milk production What happens with suckling? –Skin is enriched with free nerve endings and Meissner’s corpuscles. Stimulation during suckling releases prolactin from ant. Pituitary and induces the release of oxytocin from the posterior pituitary

52. 9/16/2015 Free Template from www.brainybetty.com 52 Breast Cancer Remember that tumors arise from epithelial cells of the lactiferous ducts

53. Image Review

54. 9/16/2015 Free Template from www.brainybetty.com 54 Identify the amnion which consists of a simple cuboidal epithelium and an underlying layer of connective tissue.

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57. 9/16/2015 Free Template from www.brainybetty.com 57 stem villi originating from the chorionic plate. They are filled with mesenchyme and lined by the two layers of trophoblast cells. The inner layer, the cytotrophoblast, divides and gives rise to the outer layer, the syncytiotrophoblast.

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61. 9/16/2015 Free Template from www.brainybetty.com 61 Mature Placenta The cytotrophoblast has disappeared and there is now one layer of syncytiotrophoblast. In places, the cytoplasm has thinned and the nuclei have accumulated in groups and clusters. These are called SYNCYTIAL KNOTS. Some of the villi show acellular pink- staining material called FIBRINOID which covers the surface.

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64. 9/16/2015 Free Template from www.brainybetty.com 64 Also, in mature placental villi are many more capillaries that lie closer to the surface.

65. 9/16/2015 Free Template from www.brainybetty.com 65 Look at the maternal side of the placenta, where ANCHORING VILLI can be seen embedded in uterine epithelia. The DECIDUAL BASALIS with the DECIDUA cells are found in the endometrium.

66. 9/16/2015 Free Template from www.brainybetty.com 66 Note anchoring villi on right

67. 9/16/2015 Free Template from www.brainybetty.com 67 The cord

68. All them breasts inside that shirt

69. 9/16/2015 Free Template from www.brainybetty.com 69 In the immature mammary gland, there is a lot of connective tissue around the glandular cells

70. 9/16/2015 Free Template from www.brainybetty.com 70 immature Lots of CT, not a lot of glands

71. 9/16/2015 Free Template from www.brainybetty.com 71 Immature again

72. 9/16/2015 Free Template from www.brainybetty.com 72 mammary gland of pregnant woman show little intralobular connective tissue and much glandular tissue

73. 9/16/2015 Free Template from www.brainybetty.com 73 Mammary gland of pregnant woman: no lipid in cells!

74. 9/16/2015 Free Template from www.brainybetty.com 74 vs. lactating A lot of gland, not a lot of CT and LIPID IN THE CELLS (pregnant but not lactating does not have this)

75. 9/16/2015 Free Template from www.brainybetty.com 75 lactating

76. 9/16/2015 Free Template from www.brainybetty.com 76 lactating

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