After ovulation, the ruptured follicle is transformed into the hormone-secreting structure called the

After ovulation, the ruptured follicle is transformed into the hormone-secreting structure called the corpus luteum.  
The corpus luteum or yellow body is an endocrine structure which is temporarily formed inside the female ovaries and is involved in the production of hormones such as progesterone, moderate levels of estradiol, inhibin A and small amounts of estrogen. The corpus luteum is essential for and maintaining the early stages of pregnancy in females.