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Question
Explain the role of pituitary and the ovarian hormones in menstrual cycle in human females
Solution
Menstrual cycle starts with menstrual flow (3 to 5 days), caused due to the breakdown of the endometrium of the uterus, which is followed by the follicular phase. In this phase, the primary follicles mature into the Graffian follicles. This causes the regeneration of the endometrium.
These changes are brought about by ovarian and pituitary hormones.
• In this phase, the release of gonadotropins (LH and FSH) increases. This causes follicular growth and the growing follicles produce oestrogen.
• The LH and FSH are at their peak in the middle of the cycle (14th day), and cause the rupture of the Graffian follicles to release ovum. This phase is called the ovulatory phase.
• The remains of the Graffian follicles get converted into the corpus luteum, which secretes progesterone for the maintenance of the endometrium.
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