PLACENTA -

1. Placenta is the intimate connection between the foehls and the uterine wall of the mother to exchange the materials.
2. Placenta is a tempormy endocrine gland.
3. During pregnancy the placenta provides for the exchange of nutrients and wastes between the mother and the developing foetus.
4. It secretes some hormones like oestrogens, progesterone, human chorionic gonadotropin (hCG), human chorionic somatomammotropin hCS (formerly known as human placental lactogen), chorionic thyrotropin, chorionic corticotropin and relaxin.
5. Oestrogens and progesterone have the same roles as in the nonpregnant state. However, the placental progesterone also checks contraction of uterine muscles and thus helps in maintain pregnancy.
6. hCG stimulates progesterone release from the corpus luteum and maintains it. Presence of hCG in urine indicates pregnancy.
7. Human choronic somatomammotropin stimulates the growth of mammary glands.
8. Placental relaxin causes relaxation of the ligaments of pubic symphysis and towards the termination of pregnancy it softens and widens the opening of the cervix (lower part of uterus) for easy child birth (parturition).