In the context of morphogenesis, living structures take shape. In humans, morphogenesis is divided into embryogenesis and fetogenesis. Morphogenesis is part of ontogenesis. Ontogenesis is the opposite of phylogenesis. Thus, not the tribal development, but the development of the individual being is important here.
The morphogenetic development includes all stages of the living organism. It begins with the development of the germ and extends to fully developed life forms. At the end of morphogenesis stands the organism with its characteristic shape. Morphogenesis is the basis of developmental biology.
Human morphogenesis is divided into embryogenesis and fetogenesis. Embryogenesis is the stage of embryonic development. It begins with the fertilization of the female egg and ends with the onset of fetogenesis.
Embryogenesis is divided into a preembryonic phase and an embryonic phase. The preembryonic phase includes the first three weeks of pregnancy. Here are the three cotyledons named Entoderm, Mesoderm and Ektoderm. The development of the zygote to the blastocyte also belongs to the preembryonic period. During this blastogenesis, the fused egg-sperm cell becomes a fluid-filled cavity with pluripotent stem cells. In the embryonic phase, the embryonic organs of the organs form. This phase lasts from the fourth to the eighth week of pregnancy.
However, embryogenesis can be subdivided not only into these two phases, but also with regard to individual organs and organ systems. Embryonic head development, embryonic heart development and embryonic liver development are differentiated. Organ development in these phases is also referred to as organogenesis.
Embryogenesis is followed by fetogenesis. The organs created in embryogenesis continue to develop here. In addition, there is a differentiation of the tissues. The stage of fetogenesis begins on the 61st day of pregnancy and ends at birth.
Fetogenesis is characterized by rapid body growth. The facial proportions of the unborn child change, eyes and ears reach their final position. Arms and legs get longer and form proportionally. Already in the third month of pregnancy this allows the unborn child's first muscle activities. In the sixth month, the skin grows very strong. Since the underlying fat layer does not grow so fast, the fetus appears wrinkled. At the seventh month of pregnancy, the morphogenesis of the lung is completed. The unborn child could now breathe independently. From this week preterm infants are therefore considered viable.
The last months of pregnancy are all about growth. The morphogenesis of the vital organs comes to an end here. In the ninth month, the morphogenesis of the organs is finally completed. The unborn child will not be much bigger either. It sinks deep into the mother's pelvis and takes its birth position. About 40 weeks after the first day of the last rule, the birth takes place.
In all stages of morphogenesis, disorders can occur. Depending on the time and severity, the consequences can be very diverse. Depending on the time of the disturbance, different disturbances can be distinguished. Blastopathies are due to a disorder of morphogenesis during blastogenesis, which occurs from the 1st to the 18th day of embryo. Embryopathies are developmental disorders that are caused during the third to eighth embryonic week. Fetopathies are diseases of the fetus (fetus). Here, the morphogenesis is affected from the ninth embryonic week.
Possible causes of morphogenesis disorders may be genetic or exogenous. Exogenous causes include certain medications, maternal infectious diseases, maternal diabetes mellitus and mother alcohol consumption. Alcohol in particular often seriously damages the unborn child. Ethanol is a cytotoxin and inhibits cell division. About one third of all children of alcoholic women are born with alcoholic embryopathy. Typical is a combination of dwarfism, mental retardation, a too small head and facial anomalies. This combination is also referred to as fetal alcohol syndrome.
Even viruses or bacteria can disturb the morphogenesis. During pregnancy, a rubella disease of the mother can have serious consequences for the child. The viruses are transmitted to the unborn child via the placenta, hindering cell division and cell differentiation. This leads to either abortion or rubella embryopathy. Embryopathy can cause various malformations. The central nervous system (CNS), the eyes and ears as well as the heart are particularly affected. It comes to encephalitis, glaucoma, deafness or deafness, growth delays or congenital heart defects. A common symptom combination consists of deafness, lens opacification and heart failure.
About 10% of infected newborns die as a result of the infection. Therapy is no longer possible after the infection. The maternal vaccine protection should therefore already be secured before a possible pregnancy. If a pregnancy is planned, therefore, the rubella titer should be determined. If the protection is insufficient, it can be revaccinated early. In the case of a pregnant woman, however, the vaccination should not be carried out. The unborn child could become infected with the vaccine virus.Tags: