embryogeneza

Embryogeneza refers to the process of development of an embryo from the zygote. This complex series of events begins with fertilization, where a male sperm cell fuses with a female egg cell to form a single diploid cell called a zygote. The zygote then undergoes rapid cell division through a process called cleavage, forming a ball of cells.

Following cleavage, the embryo enters the morula stage, which is a solid mass of blastomeres. Further development leads to the formation of the blastocyst, a hollow ball of cells with an inner cell mass that will eventually develop into the fetus. The blastocyst then implants in the uterine wall, marking the beginning of pregnancy.

Once implanted, the cells of the inner cell mass differentiate into three primary germ layers: the ectoderm, mesoderm, and endoderm. These germ layers are the precursors to all the tissues and organs in the body. The ectoderm gives rise to the nervous system and skin, the mesoderm forms muscles, bones, and the circulatory system, and the endoderm develops into the digestive and respiratory systems.

Organogenesis, the formation of organs, then begins as these germ layers fold, invaginate, and differentiate further. This is a highly organized process involving intricate cell signaling and gene expression. The developing embryo is particularly vulnerable during embryogenesis, and disruptions at this stage can lead to congenital abnormalities. The entire process of embryogenesis is a remarkable journey from a single cell to a complex organism, driven by precise genetic programming and environmental cues.