Membrane sac

Sac of membranes is a term used in obstetrics. These are amniotic sacs surrounding the fetus, in which amniotic fluid is present. From the point of view of histology and embryology, it is a fused amnion and chorion. Around the fifth month of pregnancy, this amniochoric membrane attaches to the surrounding uterine mucosa, thereby completely closing the uterine cavity. Instead of the uterine cavity, the placenta and the amniochorial membrane filled with amniotic fluid, the so-called sac of membranes, are located in the center of the uterus on its mucous membrane.

Let's not forget that we have two types of chorion. The chorion laeve, which is on the decidue capsularis, and the chorion frondosum , which is on the decidue basalis (ie, the placenta). It is the chorion laeve with the decidua capsularis that grows to the decidua parietalis, thereby completely filling the uterine cavity.

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 * Internal examination (midwifery)