Placental Exchange Mechanisms & Pathology

Question 1

What types of molecules use lipid soluble diffusion in placental transport?

Answer 1

O2, CO2, anesthetics, alcohol

Question 2

what types of molecules use lipid insoluble diffusion in placental transport?

Answer 2

many other drugs (other than ethanol), and most peptides

Question 3

what types of molecules use facilitated diffusion in placental transport?

Answer 3

most lipids and glucose (via GLUT1,3)

Question 4

what types of molecules use active transport in placental transport?

Answer 4

calcium, phosphate, amino acids, and probably omega-3 FA’s

Question 5

what types of molecules use vesicular transport in placental transport?

Answer 5

Iron transport proteins and IgG

Question 6

How is water transported across the placenta?

Answer 6

hydro-osmotic gradients (Starling-Forces)

Question 7

Answer 7

Complete Hyatidiform Mole: appears a “bag of grapes” grossly; diploid 46XX tumor (both X’s from Dad); associated with increase risk for choriocarcinoma

Question 8

Answer 8

Hyatidiform Moles: histo has central cisterns, proliferation, and islands in stroma

Question 9

Answer 9

Invasive mole: looks like choriocarcinoma, except see villus in upper L hand corner (arrow)

Magnified picture shows mitotic bodies

Question 10

Answer 10

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

Question 11

Answer 11

Green placenta due to meconium; is physiological at time of delivery and may be insignificant, but chronic release is a sign of fetal distress

Question 12

Answer 12

Marginal cord insertion; at risk for tearing of vessels and hemorrhage

Question 13

Answer 13

Lines of Zahn; seen in placenta infarction; represent layers of blood deposed with each maternal heartbeat.

Question 14

Answer 14

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

Question 15

Answer 15

Normal decidua is a wall

Question 16

Answer 16

Placenta Accreta: chorionic villi attach to myometrium; requires manual extraction; rare increased risk of LTCS

Question 17

Answer 17

Placenta Increta (invades myometrium) or Percreta (peforates myometrium)

Question 18

Answer 18

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