NURS 3112 Chapter Notes - Chapter 11.2: Fetus, Human Placental Lactogen, Miscarriage
14 Sep 2017
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Document Summary
Placental exchange functions occur only in those fetal vessels that are in intimate contact with the covering syncytial membrane. The syncytium villi have brush borders containing many microvilli, which greatly increase the exchange rate between maternal and fetal circulation. The placental functions, many of which begin soon after implantation, include fetal respiration, nutrition, and excretion. To carry out these functions, the placenta is involved in metabolic and transfer activities. In addition, it has endocrine functions and special immunologic properties. The placenta produces glycogen, cholesterol, and fatty acids continuously for fetal use and hormone production. The placenta also produces numerous enzymes required for fetoplacental transfer such as sulfatase, which enhances excretion of fetal estrogen pre- cursors, and insulinase, which increases the barrier to insulin. It breaks down certain substances, such as epinephrine and histamine. Tr a n s p o r t f u n c t i o n s.
