Study the flow chart given below.Name the hormones involved at each stage and explain their role..
(i) Ovulation:-The process of release of mature egg from the ovary is known as ovulation. It is controlled by Leuteinizing Hormone, secreted from anterior pituitary gland.
(ii)Pregnancy itself is a long duration period of 9 months which involves the formation of placenta and foetal growth. Pregnancy takes place when egg is fertilized by sperm and this fertilized egg gets implanted in wall of uterus. During pregnancy,placenta acts as an endocrine gland, and produces the human chorionic gonadotropins, human placental lactogen, oestrogen, progesterone and relaxin (later stages of pregnancy).These hormones support foetal growth and help in the maintenance of pregnancy. Hormones like estrogen, progesterone, cortisol, prolactin, etc are increased several folds in the maternal blood.
(iii)Parturition:-The delivery of the foetus through vigorous uterine contractions at the end of pregnancy is known as Parturition. It is regulated by hormone known as Oxytocin, secreted from pituitary,which causes stronger uterine contractions.