BIO380H5 Lecture 8: Development of a human embryo
Document Summary
Just below the plasma membrane of the oocyte are these cortical granules (subcellular groups of proteins: once the sperm enters, you get the fusion of the granules, be comfortable with all the terms. Some ectopic pregnancies can occur if implantation occurs too early or if the egg implants somewhere else. Cleavage: during the first division, the polar body is still around it cant really go anywhere because of the zona pellucida, the rotational cleavage generates 4 cells. Compaction: compaction occurs between the 8 cell stage and the 16 cell morula stage, the cells get really close and tight. Formation of the blastocyst: after compaction, there is the formation of the blastocyst. In the early blastocyst, you get this cavity that starts to form between the blastomeres and due to the influx of sodium which then attracts water, you get this expansion which forms the blastocoele.
