A connection between foetal membrane and uterine wall is known as placenta.
a. Mention the functions of placenta.
b. What is the fate of placenta after parturition?
c. Sometimes the expulsion of placenta is followed by bleeding. Give reason.

Explanation

a.Functions of placenta
i. It acts as a barrier between the foetus and the mother.
ii. It acts as an ultrafilter.
iii. Soluble inorganic and organic materials, nutrients, hormones, antibodies against diphtheria, small pox, scarlet fever, measles etc. can pass through the placenta from mother to foetus.
iv.It helps in the exchange of gases between the mother and the foetus.
v. It helps in the elimination of nitrogenous discharges and other wastes of the foetus.
vi.It acts as an endocrine gland and produces hormones such as HCG, chorionic thyrotropin, chorionic corticotropin, chorionic somatomammotropin, estrogens and progesterone. It also secretes progesterone until the end of pregnancy. At the time of parturition, the placenta secretes relaxin, which helps in the relaxation of pubic ligaments to enable birth of the child.
b.Shortly after the baby is born, the placenta and the remains of the umbilical cord, known as the afterbirth is expelled out.
c.Because the vascular tissues are damaged in the process of parturition.