During this period, occurs, establishing the primitive versions of major organ systems. This stage is also the most vulnerable to teratogens , environmental factors like drugs or infections that can cause congenital malformations. Maturation and Growth: The Fetal Stage
Develops into the circulatory system, muscles, bones, and kidneys. Download (01) embryologie humaine embryologie humaine pdf
Human development begins with fertilization, the fusion of male and female gametes to form a single-celled . This initial phase, known as the germinal stage (Weeks 1–2), is characterized by rapid cell division called cleavage . As the zygote travels toward the uterus, it transforms into a morula and then a blastocyst , eventually implanting into the uterine wall. This critical "molecular conversation" between the embryo and the uterus is foundational for a successful pregnancy. The Blueprint of Complexity: The Embryonic Period Human development begins with fertilization, the fusion of