Functions of Placenta
Respiration - As pulmonary exchange of gases does not takeplace in the uterus the fetus must obtain oxygen and excrete carbon dioxide through the placenta
Nutrition - Food for the fetus derives from the mother’s dietand has already been broken down into forms by the time reachs the placenta site. The placenta is able to select those substances required by the fetus, even depleting the mother’s own supply in some instances.
Storage - The placent metabolises glucose and can alsostores it in the form of glycogen and reconverts it to glucose as required. The placenta store iron and the fat soluble vitamins.
Excretion -The main substance excerted from the fetus iscarbondioxide; bilrubin will also be excreted as red blood cells are released relatively frequently.
Protection - It provides a limited barrier to infection with theexception of the treponeona of syphilis and, few bacteria can penetrate. Viruses, however, can cross freely and may cause congenital abnormalities as in the case the rubella virus and HIV virus.
Endocrine - Human chorinnic gondotroghin (HCG) isproduced by the cytotrophoblastic layer of the chorinonic villi.
· Oestrogens as the activity of the corpus luteum declines, the placenta takes over the production of oestrogen, which are secreted in large amounts through out pregnancy.
· Human placental lactogen (HpL) has a role in glucose metabolism in pregnancy.
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