Placenta and Fetal membranes S2M3

  1. The placenta is a fetomaternal organ, what regions are fetal, and which maternally derived
    • Fetal - Chorion Frondosum (Villus chorion)
    • Maternal - Decidua basalis
  2. What are the three layers of the Decidua
    • Decidua basalis
    • Decidua capsularis
    • Decidua parietalis
  3. Decidua basalis
    • Portion of the endometrium that forms the maternal part of the placenta
    • Connects embryo to the uterus
  4. Decidua capsularis
    Superficial part of the decidua that overlies the conceptus (embryo) distal to the stalk
  5. Decidua parietalis
    This is the portion of the decidua that lines the uterine wall accept where the stalk connects
  6. Chorionic villi cover the entire chorionic sac until when
    Beggining of the 8th week
  7. Smooth chorion
    Villi in the decidua capsularis become compressed and degenerate forming an avascular bare area called the smooth chorion
  8. What happens to the chorionic villi in the decidua basalis area
    They increase in number and size forming the chorion frundosum
  9. Chorionic cavity
    This is the space between the amniotic cavity and the decidua where the eventual chorionic villi emerge
  10. Fetomaternal junction
    This is where the Villi chorion is attached to the decidua basalis by the cytotrophoblastic shell where Endometrial arteries and veins pass through
  11. Amniochorionic membrane
    This is the fusion of the amniotic sac and the smooth chorion which adheres to the decidua parietalis
  12. What membrane ruptures during labor
    Amniochorionic membrane
  13. Placenta Septa
    Wedged shape areas of decidua that project to the chorionic plate creating incomplete compartments
  14. What is the intervillus space lined by
  15. How does the maternal blood not mix with the fetal blood
    Maternal blood flows into the intervillus space from the spiral arteries and flows over the branched villi transfereing nutrients but not blood
  16. What is transfered to the fetus in maternal/fetal circulation
    • Nutrients
    • Electrolytes
    • Glucose
    • Amino Acids
    • Free fatty acids
    • Carbohydrates
    • Vitamins
  17. What is not transfered to the fetus
    • Cholesterol
    • Triglycerides
    • Phospholypids
  18. What takes oxygenated blood to the fetus from the placenta
    Umbilical vein
  19. Blood returns to the mother from the placenta through
    Endometrial veins
  20. What are the layers of the placental membrane
    • Syncytiotrophoblasts
    • Cytotrophoblasts
    • Connective tissue
    • Endothelium of the fetal capillaries
  21. When does the placental membrane reduce to 2 layers instead of 4
    20th week when the cytotrophoblasts decrease in number
  22. What two membranes remain after the placental membrane reduces to two layers
    • Syncytiotrophoblasts
    • Endothelium of fetal capillaries
  23. What are the general functions of the Placenta
    • Metabolism
    • Transport gases and nutrients
    • Endocrine secretion
  24. By what methods does transportation happen across the placenta
    • Simple diffusion
    • Facilitated diffusion
    • Active transport
    • Pinocytosis
  25. What is the only antibody that crosses the placenta
    • IgG
    • "Gestation"
  26. What are some of the diseases that a fetus can gain immunities to
    • Diphtheria
    • Smallpox
    • Measles
  27. Erythroblastosis fetalis
    Rh+ blood in the mother stimulates attack of Rh- blood of the fetus, killing the fetus
  28. Syncytiotrophoblasts of the placenta produce what proteins and steroid hormones
    • Human chorionic Gonadotropin (hCG)
    • Human chorionic Somatomammotropin (hCS)
    • Human chorionic Thyrotropin (hCT)
    • Human chorionic Corticotropin (hCACTH)
  29. What is the role of hCG
    Maintains corpus luteum and is used to determine pregnancy in mothers urine in the 2nd week
  30. What is the role of hCS
    • This allows the fetus priority on the maternal blood glucose (this can cause the mother to be diabetogenic)
    • It also promotes breast development and milk production
  31. When does the placenta take over as the main provider of progesterone
    By the fourth month
  32. When does Estriol reach its max in pregnancy, and what is its role
    • Just before the end of pregnancy
    • It stimulates uterine growth and development of mammary glands
  33. What are the only proteins that cross the placenta
    • T4
    • T3
    • Unconjugated steroids
    • Diethystilbestrol (synthetic estrogen)
  34. What are some viruses that cross the placenta
    • Rubella
    • Cytomegalovirus
    • Coxsackie
    • Variola
    • Varicella
    • Measles
    • Poliomyelitis
  35. Toxoplasmosis gondii causes what defects
    Damage to the brain and eyes
  36. The amnionic cavity enlarges rapidly during development and eventually
    Envelops the connecting stalk and yolk sac stalk resulting in the primitive umbilical cord
  37. What is the role of the amnionic fluid
    • Absorbs jolts
    • Allows fetal movement
    • Prevents adherence to the amnion
    • Maintains body temp
    • Barrier to infections
Card Set
Placenta and Fetal membranes S2M3
Micro Anatomy