Reproduction & Development I: Placenta Layers by Species

Question 1

Epitheliochorial

Answer 1

6 layers, no gas or immunologic exchange between maternal and fetal blood, absolutely requires colostrum

Horses, sows, ruminants, alpacas

Question 2

Endotheliochorial

Answer 2

4-5 layers, has partial exchanges of gases and immunoglobulins between fetal and maternal blood, still requires colostrum

dogs, cats

Question 3

Hemochorial

Answer 3

3 layers, chorion sitting in maternal blood, complete exchange of gases and immunoglobulins in utero

humans, primates, rodents