Question

How is placenta formed in a human female? Name a hormone produced by the placents and ovary only during pregnancy in a human female.

Answer 1

Placenta is the site of exchange of nutrients and wastes between the mother and fetus. It has two distinct parts by the beginning of twelfth week of embryo development: (a) the fetal portion formed by the chorionic villi of the chorion and (b) the maternal portion formed by the decidua basalis of the endometrium. The actual connection between the placenta and embryo is through the umbilical cord, which develops from the connecting stalk and is usually 2 cm wide and about 50-60 cm in length.
Placenta produces a number of hormones such as human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progesterones, etc. In later stages of pregnancy, hormone relaxin is also produced by it. Ovary secretes high levels of progesterones and estrogens during pregnancy.