functions of placenta

Functions of placenta?The placenta is a fetal organ (it is the only means of
transfer of anabolites and catabolites between the
fetus and the outside world?1. Act as a fetal lungs (providing respiratory function)
by continuously transferring O2 and CO2.
?2. Nutrient function (replace the GIT during the fetal
life).
?3. Excretion of hydrogen ions and other waste
products pass from the fetal to the maternal blood (act
as kidneys).
?4. Forms a barrier against the transfer of infection to
the fetus, although some organisms e.g Rubella and
HIV viruses are able to cross it.?5. Act as endocrine gland producing numerous
hormones which are necessary for the maintenance of
pregnancy and the initiation of parturition (estrogen,
progesterone, PG, HCG, HPL, relaxin, TSH, pituitary
peptides, and releasing factors.
?6. Play a role in the immune system of the fetus (by
providing it with immunoglobulin through the
transfer from maternal circulation (permit only IgG,
but not IgA or IgM ).
?7. Some functions of the liver such as detoxification of
drugs and other substances presented to it by the
maternal circulation.