Q.Explain the various phases of the menstrual cycle.

The menstrual cycle is the roughly 28-29 day hormonal rhythm that runs from menarche to menopause (pausing only during pregnancy), coordinating parallel changes in the ovary and the endometrium under the control of pituitary FSH/LH and ovarian oestrogen/progesterone. It has four phases: the menstrual phase (days 1-5, the endometrium sheds as progesterone and oestrogen fall following an unfertilised cycle); the follicular/proliferative phase (day 5 to ovulation, rising FSH/LH mature a Graafian follicle while its oestrogen output regenerates the endometrium); the ovulatory phase (around day 14, a sharp mid-cycle LH surge, alongside peak FSH, ruptures the Graafian follicle and releases the secondary oocyte — ovulation); and the luteal/secretory phase (the ruptured follicle becomes the corpus luteum, secreting progesterone to sustain the endometrium; without fertilisation it degenerates in …