Placental Exchange Mechanisms & Pathology Flashcards
What types of molecules use lipid soluble diffusion in placental transport?
O2, CO2, anesthetics, alcohol
what types of molecules use lipid insoluble diffusion in placental transport?
many other drugs (other than ethanol), and most peptides
what types of molecules use facilitated diffusion in placental transport?
most lipids and glucose (via GLUT1,3)
what types of molecules use active transport in placental transport?
calcium, phosphate, amino acids, and probably omega-3 FA’s
what types of molecules use vesicular transport in placental transport?
Iron transport proteins and IgG
How is water transported across the placenta?
hydro-osmotic gradients (Starling-Forces)
Complete Hyatidiform Mole: appears a “bag of grapes” grossly; diploid 46XX tumor (both X’s from Dad); associated with increase risk for choriocarcinoma
Hyatidiform Moles: histo has central cisterns, proliferation, and islands in stroma
Invasive mole: looks like choriocarcinoma, except see villus in upper L hand corner (arrow)
Magnified picture shows mitotic bodies
Choriocarcinoma: super rare, malignant tumor of syncytiotrophoblasts and cytotrophoblasts; complete mole a risk factor; can mets to lungs, vagina, and brain
reponds well to chemo
Green placenta due to meconium; is physiological at time of delivery and may be insignificant, but chronic release is a sign of fetal distress
Marginal cord insertion; at risk for tearing of vessels and hemorrhage
Lines of Zahn; seen in placenta infarction; represent layers of blood deposed with each maternal heartbeat.
A) normal placenta position
B) Retroplacental Abruption: a hematoma between placenta and uterus that obstructs maternal BF to fetus; assoc. w/ pre-eclampsia and trauma
C) Placenta Accreta: chorionic villi attach to myometrium; must manually extract
D) Placenta Previa: overlying cervix, risk of life-threatening hemorrhage and placenta accreta
Normal decidua is a wall
Placenta Accreta: chorionic villi attach to myometrium; requires manual extraction; rare increased risk of LTCS
Placenta Increta (invades myometrium) or Percreta (peforates myometrium)
A) Chorioamnionitis: see marginating neutrophils; part of maternal response to ascending infection; highly sensitive for amniotic infection
B) Funisitis: fetal response to infection; see neutrophils marginating into umbilical cord; highly specific
C) Placental Insufficiency
D): Placental Abruption: see lines of zahn
