Maternity & Kid's Care

Posts Tagged ‘trophoblast’

The period of embryo begins from the zygotes attachment to the uterine wall. This period usually lasts from two weeks after fertilization to the eighth week. By the end of the period of ovum, the egg has two distinct parts, one inner cell mass and the outer layer called trophoblast. The inner called mass differentiates into three clear layers. Of the three layers the outer layer is ectoderm from which develop the outer layer of skin, the hair, the nails, parts of teeth, skin, glands, sensory cells and nervous system. The middle layer is called mesoderm from which develop inner skin layer, the muscles, skeleton and the circulatory and excretory organs.

The inner layer is called endoderm from which will develop the lining of the entire gastro intestine tract, the trachea, bronchia, lungs, liver, pancreas, salivary glands, thyroid glands and thymus. The outer layer will develop into accessory tissues, which protect and nourish the embryo.

As the embryo grows, additional life supporting structure continues to develop. Among these, the umbilical cord and placenta which maintain the connections with the mother’s body through which the embryo gets nutrients and expels waste. Placenta is a membranous organ into which mother’s blood stream and foetus blood stream end. Nutrients from the mother’s blood pass to the foetus through placenta. Amniotic sac acts as a buffer to protect the embryo from shocks experienced by the mother.