The structures labeled A on both diagrams are called
A)amniotic cavities
B)chorionic villi
C)decidua basilus
D)intervillous spaces
E)yolk sac vestiges

Question

The structures labeled A on both diagrams are called 
A)amniotic cavities 
B)chorionic villi 
C)decidua basilus 
D)intervillous spaces 
E)yolk sac vestiges

Quizplus · Accepted Answer

The structures labeled A on both diagrams are chorionic villi. Chorionic villi are finger-like projections that grow from the chorion (the outermost membrane surrounding the embryo) into the surrounding tissue of the uterus. They serve to increase the surface area between the fetal and maternal blood vessels for exchange of nutrients, gases, and waste products.

The Structures Labeled a on Both Diagrams Are Called