Placenta is the mechanical and physiological connection between foetal and maternal tissues for the nutrition, respiration and excretion of the foetus. Placenta it is richly of blood supply because it contain a capillary network of blood vessels. The main functions of the formation of placenta to the pregnant mother’s includes;-
(1) Nutrition; Placenta helps to transport nutrients from maternal blood into foetus
(2) Respiration; It helps in getting oxygen from the maternal blood into the foetus and Carbon dioxide from foetus blood into the maternal blood.
(3) Excretion; Nitrogenous waste products produced in the embryo diffuse through the placenta into the maternal blood stream.
(4) Immunity; Antibodies developed in the mother against certain diseases like measles, small pox, diphtheria pass from mother into the foetal blood through the placenta.
(5) Transport of pathogens; Pathogenic organisms like viruses diffuses through the placenta. Viruses causing syphilis, measles, rubella, small pox may infect the foetus, if the mother gets the disease during pregnancy. Some of these diseases may even cause congenital deformities.
(6) Transport of drugs; Some of the drugs taken by the mother during pregnancy cross the placental barrier and may even cause developmental deformities.
(7) Secretion of hormones; Placenta secretes many hormones like estrogen, progesterone, gonadotropin and placental lactogen, thus functioning as an endocrine gland.