The Smith County Veteran Services Office will be closed Monday through Monday, August 15-22, 2016. The Smith County Veterans Service Office will be closed Monday through Monday, August 15-22 for training, and will reopen on Tuesday, August 23 for normal business hours.
The first differentiation event in the formation of the placenta is the formation of trophoblasts, specialized epithelial cells, that ultimately form a physical connection between the embryo and the uterus. Allocation of cells to the trophoblast lineage is dependent on their position at the morula stage.
The placenta is composed of both maternal tissue and tissue derived from the embryo. The chorion is the embryonic-derived portion of the placenta. It is composed of trophoblasts, which you may remember are the cells that made up the outer cell layer of the blastocyst.et's review. The placenta is the composite structure of embryonic and maternal tissues that supplies nutrients to the developing embryo. The placenta serves three main functions: 1  Attach the fetus to the uterine wall. 2  Provide nutrients to the fetus.