The term "decidual" refers to an anatomical or histological characteristic found primarily in mammals. It describes a phenomenon related to the endometrium, which is the inner lining of the uterus. During pregnancy, the decidualization process occurs in preparation for the implantation of a fertilized embryo.
Decidualization involves significant changes in the endometrial cells, specifically in the stromal cells. These cells undergo a transformation, acquiring a secretory phenotype that is different from their regular state. The decidual cells become larger, more rounded, and filled with glycogen, making them highly active and capable of producing various substances necessary for pregnancy.
One of the key functions of the decidual tissue is to establish a connection between the embryo and the maternal blood supply. This process occurs as the decidual cells accumulate around the trophoblast, a specialized structure that forms from the outer layer of the embryo. The interaction between the decidual tissue and the trophoblast is crucial for the placental development and the exchange of nutrients and waste products between the mother and the developing fetus.
Furthermore, decidualization also plays a role in the immune response during pregnancy. The decidual cells, in coordination with immune cells, help to regulate the immune system's activity in the uterus, ensuring tolerance towards the developing embryo while maintaining protection against infections.
In summary, decidual refers to the changes that occur in the endometrium of mammals during pregnancy, leading to the formation of specialized decidual cells. These cells play vital roles in establishing a connection between the embryo and the mother, facilitating placental development, nutrient exchange, and immune regulation.
