Development of the Human Zygote

November 16, 1995         Hundreds of thousands of times a year a single-celled zygote, small than a grain of sand, trans work outs into an amazingly complex network of cells, a newborn infant. Through cellular differentiation and growth, this performance is established with precision time and time again, but actually seldom a mistake in the blueprint of growth and teaching does occur. following(a) is a description of how the pathways of this intricate web ar followed and the mistakes which lessen out when they are not.         The impressive process of differentiation changes a single-cell into a complicated system of cells as distinct as vaporous and bone. Although fertilized eggnic development takes approximately nine months, the greatest juncture total of cellular differentiation takes place during the first octonary workweeks of pregnancy. This finis is called embryogenesis.         During the first week afte r fertilization, which takes place in the Fallopian tube, the embryo starts to cleave once every twenty-four hours (Fig. 1). Until the 8 or sixteen cell stage, the individual cells, or blastomeres, are panorama to have the potential to form any section of the foetus (Leese, Conaghan, Martin, and Hardy, April 1993). As the blastomeres continue to divide, a solid lout of cells develops to form the morula (Fig. 1). The accumulation of fluid inside the morula, transforms it into a mindless expanse called a blastula, which implants itself into the inner lining of the uterus, the endometrium (Fig. 1). The inner aggregative of the blastula go forth produce the embryo, while the outer(prenominal) layer of cells will form the trophoblast, which eventually will raise nourishment to the egg cell (Pritchard, MacDonald, and Gant, 1985). Figure 1: implantation process and development during embryogenesis (Pritchard, MacDonald and Gant, 1985)       Â!  Â During the second week of development, gastrulation, the process by which the germ layers are formed, begins to occur. The inner cell... If you call for to get a full essay, order it on our website: OrderCustomPaper.com

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