BIO380H5 Lecture Notes - Amnion, Twin, Blastomere
Document Summary
Ovulation -> insemination -> fertilization in fallopian tubes -> embryo moves down fallopian tube. > cleavage -> compaction -> cavitation -> multicellular blastocyst -> hatching from zona pellucida. 6-7 days after fertilization embryo binds to uterine epithelium can occur at ectopic sites. L-selectin (lymphocyte selectin) lectin: present in blastocyst, binds to sugar groups in extracellular matrix of endodermal cells, weak, initial adherence. Trophinin: homophilic, blastocyst and maternal stronger. Placenta and chorion prevent immune response from mother chorion is a group of extraembryonic membranes: placenta is maternal and extraembryonic tissues formation of decidua by maternal tissues syncytiotrophoblast, chorion and amnion interact with decidua forming placenta. Blastocyst consists of two cell types inner cell mass (icm) embryo and some extraembryonic membranes trophoblast extraembryonic membrane. Needle into maternal abdomen and uterus into amniotic cavity cells sloughed from embryo, determines sex or genetic defects fluid used to examine proteins.
