Embryonalaufbau

Embryonalaufbau refers to the structural organization and differentiation of an embryo during its early stages of development. This process begins with fertilization, where a sperm fuses with an egg to form a zygote. The zygote then undergoes rapid cell division, a process known as cleavage, resulting in a multicellular structure called a blastocyst.

The blastocyst is characterized by an inner cell mass, which will give rise to the embryo proper, and an outer layer of cells called the trophoblast, which contributes to the placenta. Following implantation in the uterine wall, the inner cell mass differentiates into three primary germ layers: the ectoderm, mesoderm, and endoderm. These germ layers are the foundational tissues from which all organs and systems of the body develop.

The ectoderm forms the outer covering of the body, including the skin, hair, and nervous system. The mesoderm develops into muscles, bones, blood, and connective tissues. The endoderm differentiates into the lining of the digestive and respiratory tracts, as well as various glands. Subsequent stages involve complex morphogenetic movements and cell signaling, leading to the formation of specific organs and the overall body plan. Understanding embryonalaufbau is crucial for comprehending normal fetal development and identifying potential congenital anomalies.