Question

Write the effect of the high concentration of L.H. on a mature Graafian follicle.

Answer 1

Hint: There is a sharp rise in the volume of LH(Luteinizing Hormone) in the blood that triggers ovulation on the 14th day of the menstrual cycle.

Complete answer:
- Within an ovary, a Graafian follicle, or ovarian follicle, is developed and is a small cyst inside which an ovum, or egg, forms. With many immature follicles, each containing an undeveloped ovum, women are born.
- Each month, one ovum matures after puberty is reached and menstruation starts. Stimulated by FSH as the oestrous cycle progresses, the Graafian follicle starts to grow deep within the ovary, steadily enlarging and maturing as it rises to the surface, finally emerging like a blister on the surface, just before the oocyte is published. The follicle after ovulation becomes a corpus luteum.
- The high concentration of LH causes the rupture of the Graafian follicle that leads to free the secondary ovum or oocyte and thus causes ovulation in women. This Graafian follicle is then converted into corpus luteum and the corpus luteum retains if fertilization happens otherwise degenerated.

Note: During the follicular stage and secretory stage, LH and FSH i.e., gonadotropins levels steadily raise, respectively, FSH induces follicular growth and oestrogen secretion by the rising follicles, while LH induces the corpus luteum to secrete progesterone. In the middle of the cycle, both LH and FSH achieve a peak stage, i.e. around the 14th day of the menstrual cycle.