Question

Why oestrogen levels increase and progesterone levels decrease?

Answer 1

during menstrual cycle , graffian follicle releases ovum and forms as corpus luteum which secretes progesterone which maintains endometrium for implantation if fertilization occurs.wen the ovum is ruptured in the absence of fertilization... the progesterone levels decrease and endometrial lining breaks leading to menstruation. at that time of ovulation oestrogen levels become high .