What is the primary role of chorionic villi?

The primary role of chorionic villi is to facilitate nutrient exchange and develop the placenta. Chorionic villi are small, finger-like projections that extend from the chorion, one of the membranes surrounding the developing embryo. They penetrate into the maternal tissue, forming a crucial interface between the mother and the fetus.

Through these villi, oxygen and nutrients from the maternal blood are transferred to the fetal blood, while waste products from the fetus are removed back to the mother. This exchange is essential for fetal growth and development, as it ensures the embryo receives the necessary substances for proper development, particularly in the early stages of pregnancy when the developing fetus is entirely reliant on maternal resources. Furthermore, the chorionic villi play a critical role in the formation of the placenta, which continues to support the fetus throughout gestation. This function highlights the importance of chorionic villi in establishing and maintaining a healthy pregnancy.

Other choices, while they may relate to aspects of pregnancy, do not accurately capture the primary role of chorionic villi in the context of nutrient exchange and placental development.