During implantation, the
A) trophoblast erodes a path through the endometrium.
B) inner cell mass begins to form the placenta.
C) maternal blood vessels in the endometrium are walled off from the blastocyst.
D) entire trophoblast becomes syncytial.
E) inner cell mass is temporarily deprived of nutrients.

Question

Quizplus · Accepted Answer

During implantation, the trophoblast erodes a path through the endometrium. This process is called implantation erosion, and it allows the blastocyst to firmly attach to the uterine wall and establish a connection with maternal blood vessels.

Answer: C
 During implantation, maternal blood vessels in the endometrium are walled off from the blastocyst. This creates a pool of maternal blood around the implantation site, which will eventually be used to nourish the developing embryo.

Answer: D
 During implantation, a portion of the trophoblast becomes syncytial. This syncytiotrophoblast layer plays a critical role in the establishment of maternal-fetal circulation, as it forms the outer layer of the chorionic villi and interacts with maternal blood vessels.

Answer: E
 There is no evidence that the inner cell mass is temporarily deprived of nutrients during implantation. In fact, the inner cell mass plays a critical role in establishing the embryonic disk and forming the future embryo.

During Implantation, the