Amniotic fluid

The amniotic cavity is filled with a clear, watery fluid produced by the amniotic cells and derived from maternal blood. During the early months of pregnancy, the embryois suspended by its umbilical cord in this fluid, which serves as a protective cushion. The fluid absorbs jolts, prevents the adherence of the embryo to the amnion, and allows for fetal movements. Amniotic fluid acts as a barrier to infection and contains antibodies. Also it provides homeostasis of fluid and electrolytes. At the end of pregnancy, urine is daily added to the amniotic fluid. This urine is mostly water, since the placenta is functioning as the kidney.

Figure13. Yolk sac, with newly formed blood vessels between columnar endoderm (below) and simple squamous, splanchnopleuric, extraembryonic mesoderm (above)

Дата добавления: 2015-07-25