The Chorionic Villi Sit in Blood-Filled Endometrial Spaces Called

Question

The chorionic villi sit in blood-filled endometrial spaces called
A) the umbilical cord.
B) the lacunae.
C) the yolk sac.
D) allantois.

Accepted Answer

The correct answer is B because the chorionic villi, which are necessary for nutrient and waste exchange, are situated in the lacunae, which are large blood-filled spaces within the endometrium. The umbilical cord connects the fetus to the placenta, the yolk sac provides nutrition to the developing embryo, and the allantois is responsible for waste elimination and blood vessel formation.