AP PSYCHOLOGY

Detailed explanation-1: -Trophoblasts are cells that form the outer layer of a blastocyst, which provides nutrients to the embryo, and then develop into a large part of the placenta. Trophoblast invasion is a critical process in the establishment of a successful pregnancy.

Detailed explanation-2: -Trophoblasts (from Greek to feed: threphein) are cells forming the outer layer of a blastocyst, which provides nutrients to the embryo, and develops into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg.

Detailed explanation-3: -Within 11 days of fertilization, the trophoblast forms two layers, 1st the cytotrophoblast and 2nd the syncytiotrophoblast, containing lacunae. The placenta forms a barrier to permit exchange of nutrients, gases and wastes with only slight mixing of fetal blood with maternal blood.

Detailed explanation-4: -The three potential maternal layers in a placenta are: Endothelium lining endometrial blood vessels. Connective tissue of the endometrium.