Mention the importance of $LH$ surge during the menstrual cycle.

(N/A) The $LH$ surge,which occurs in the middle of the menstrual cycle (around day $14$),is crucial for the following reasons:
$1$. It triggers the rupture of the mature Graafian follicle,leading to the release of the ovum,a process known as ovulation.
$2$. After ovulation,the remaining parts of the Graafian follicle transform into the corpus luteum.
$3$. The corpus luteum secretes high levels of progesterone,which is essential for maintaining the endometrium for the implantation of a fertilized ovum and for the successful progression of pregnancy.