Mention any two functions of the human foetal placenta.
Topic: Functions of the foetal placenta
Answer
- It supplies the foetus with NUTRITION AND OXYGEN from the mother’s blood.
- It removes the WASTE PRODUCTS of the foetus — carbon dioxide and nitrogenous wastes — into the mother’s blood for disposal.
(Also acceptable: it secretes hormones such as progesterone and oestrogen that maintain pregnancy; it acts as a barrier against certain germs.)
Two functions, one mark each, and the neatest pair is the two DIRECTIONS of exchange — in and out.
THE POINT MOST OFTEN GOT WRONG: the blood of the mother and that of the foetus DO NOT MIX. They flow close together in the placenta, separated by a thin membrane, and substances pass across it by diffusion. Writing that the mother’s blood flows into the baby is a definite error.
The placenta is remarkable because it does the work of several organs at once — lungs, digestive system, kidneys and an endocrine gland — since none of the foetus’s own organs is yet functioning.