Embryology: Development of Paraxial Mesoderm

The parietal layer forms the dermis of skin in the body wall and limbs, and also forms the bones and connective tissues of the limbs, as well as the sternum.

Mesodermal cells surround the intraembryonic cavity and form the mesothelial membrane or serous membrane, which lines the pleural, parietal, and pericardial cavities and secretes serous fluid.

The notochord and prechordal mesoderm induce the ectoderm to form the neural plate, which eventually gives rise to the neural tube.

<p>Coelom is a mesodermally lined cavity between the gut and the outer body wall, and its formation begins during the gastrulation stage.</p> Signup and view all the answers

<p>The visceral layer, along with the endoderm, forms the wall of the gut tube, and the mesodermal cells here form a thin serous membrane around each organ.</p> Signup and view all the answers

<p>Polyspermy can result in the death of an embryo because multiple sperm fuse with the egg, making the embryo genetically non-viable.</p> Signup and view all the answers

<p>Cleavage is significant in embryonic development because it increases the number of cells without an increase in mass, forming the blastula.</p> Signup and view all the answers

<p>The bilaminar germ disc is composed of the epiblast and hypoblast, which together surround the primitive yolk sac.</p> Signup and view all the answers

<p>The blastocyst stage is significant because it contains the inner cell mass, which will form the embryo proper, and the outer cell mass, which will form the trophoblast.</p> Signup and view all the answers

<p>The decidual reaction is significant because it allows the blastocyst to implant in the endometrium, ensuring a successful pregnancy.</p> Signup and view all the answers

<p>The blastula is composed of an outer layer of cells, called blastomeres, which will form the embryoblast and trophoblast.</p> Signup and view all the answers

<p>The morula stage is significant because it marks the formation of the 16-cell stage, which will eventually form the blastocyst.</p> Signup and view all the answers

<p>The uterine tube is significant because it provides a site for fertilization and early embryonic development, ensuring the successful implantation of the embryo.</p> Signup and view all the answers

<p>The inner cell mass is significant because it will form the embryo proper, giving rise to the future organism.</p> Signup and view all the answers

<p>The outer cell mass is significant because it will form the trophoblast, which will give rise to the placenta and other supporting structures.</p> Signup and view all the answers