Question

What is the menstrual cycle? Which hormones regulate menstrual cycle?

Answer 1

Hint: Menstrual cycle is the regular natural change which occurs in the female reproductive system in the uterus and ovaries .The cycle is required for the production of oocytes, and for the preparation of the uterus for pregnancy.

Complete answer:
The menstrual cycle occurs due to the rise and fall in the level of estrogen. It causes thickening of the lining of the uterus, and also the growth of an egg . The egg is released from an ovary around fourteenth day in the cycle the thickened lining of the uterus provides nutrients to an embryo after implantation. If pregnancy does not occur, the lining is released and that is called a menstruation or a "period". The first period usually begins between twelve and fifteen years of age, this time is known as menarche. They may start as early as eight, and this onset may still be normal. The length of time between the first day of one period and the first day of the next is usually 21 to 35 days in adults (an average of 28 days). Menstruation stops occurring after menopause which usually occurs between 45 and 55 years of age. Bleeding usually lasts around 3 to 7 days. Menstrual cycle is regulated by gonadotropins secreted by anterior pituitary (follicular stimulating hormone and luteinizing hormone). FSH stimulates growth, development and hormonal secretion of Graafian follicle and ovum maturation. LH stimulates maturation of Graafian follicle and LH surge between 12 to 14 days of cycle stimulates rupture of Graafian follicle and release of ovum i.e. ovulation. Gonadotropins also stimulate developing follicles to secrete progesterone and estrogen which in turn prepare the uterus for implantation and exert negative feedback regulation on the secretion of gonadotropins after ovulation.

Note: Women experience some symptoms during the one to two weeks prior to menstruation. Common symptoms include acne, tender breasts, bloating, feeling tired, irritability and mood changes. These symptoms interfere with normal life and therefore known as premenstrual syndrome.