Final answer:
Granulosa cells in the Graafian follicle shut down the production of OMIF during the LH surge because this follicle is the dominant one that survives the drop in FSH levels, leading to ovulation and luteinization, which other follicles cannot due to atresia.
Step-by-step explanation:
The LH surge results in ovulation of the dominant follicle. Only the Graafian follicle, which is now the dominant follicle, undergoes these changes because it has the most granulosa and theca cells, producing large amounts of estrogen due to LH stimulation. This elevation in systemic plasma estrogen concentrations instigates a negative feedback loop, leading to a decrease in GnRH, LH, and FSH production by the hypothalamus and pituitary.
Following ovulation, the remaining cells in the follicle undergo luteinization, transforming into the corpus luteum which secretes progesterone. Progesterone's role is crucial in establishing and maintaining pregnancy, and it exerts negative feedback on the hypothalamus and pituitary, thus maintaining low levels of GnRH, LH, and FSH and preventing the development of new dominant follicles during this time.
Why do granulosa cells only in the Graafian follicle shut down the production of OMIF? It is because only this follicle has become dominant, surviving the reduction in FSH levels, thanks to the number of its granulosa cells, size, and ability to respond to LH stimulation. It then progresses to ovulation and subsequent luteinization, whereas other follicles undergo atresia due to the lack of sufficient FSH.