Embryonic Development Research Paper

Embryonic development is the changes an embryo undergoes as it grows toward a developed organism. In early embryonic development, the first stage begins with fertilization, when the female egg fuses with the male sperm to create a zygote (Biology.OpenStax.1753). After a zygote is formed, cleavage (unusually large cell) converts the zygote to a multicellular organism (embryo) by rapidly dividing a single cell (each the same size) to form a hollow ball of cells, called a blastula. The next stage in development is when the blastula forms a blastocyst, in which the blastula divides itself into two layers called the embryoblast (inner cell mass) and the trophoblast (outer layer) (Biology.OpenStax.1754). The inner cell mass will continue to develop the embryo, and the trophoblast will eventually become part of the placenta, providing nutrients, waste removal, and oxygen to the embryo. However, the blastocyst first attaches to the uterus, called implantation, before the trophoblast becomes part of the placenta. …show more content…
The three layers (germ layers) are called ectoderm, mesoderm, and endoderm. (Biology.OpenStax.1755). The final stage is organogenesis (important stage) when the three germ layers of the gastrula develop various body organs (Biology.OpenStax.1756). During this stage, the brain, skin, and nervous system arises from the ectoderm, while the blood cells, heart, and muscle cells rise to the mesoderm. The digestive system, liver, and other internal organs give rise to the endoderm (Biology.OpenStax.1755). After this stage the embryo is called a fetus, and fetal development begins, in which several organs take their proper structure and positions the body to mature into a