Explanation

Menstruation occurs in human, apes and old world monkeys. Menstruation is bleeding from uterus of adult female at intervals of one lunar month. A reduction in oestrogens and progesterone causes menstruation. Gonadotropin releasing hormone secreted by the hypothalamus stimulates the release of FSH and LH. FSH and LH stimulate the ovarian follicles to produce more oestrogens during proliferative phase of menstrual cycle. Growth hormone (GH) has no role in the process of menstrual cycle.