Placenta is an endocrine tissue. Justify.

Explanation

(i) Human embryo is surrounded by 3 embryonic membranes. The chorionic villi and uterine tissues form the disc shaped placenta. It is a temporary endocrine organ formed during pregnancy and connects the foetus to the uterine wall through the umbilical cord.
(ii) During pregnancy, the placenta acts as a temporary endocrine gland and produces large quantities of human Chorionic Gonadotropin (hCG), human Chorionic Somatomammotropin (hCS) or human Placental Lactogen (hPL), oestrogens and progesterone which are essential for a normal pregnancy.
(iii) A hormone called relaxin is also secreted during the later phase of pregnancy which helps in relaxation of the pelvic ligaments at the time of parturition. It should be noted that hCG, hPL and relaxin are produced only during pregnancy.
(iv) Thus placenta is a endocrine tissue.