A temporary endocrine gland that is formed in the ovary after an egg has been released during ovulation. The gland forms out of the follicular sac that surrounds the egg.
The corpus luteum produces hormones such as progesterone that help prepare the uterus for pregnancy. If pregnancy does not occur, the corpus luteum will breaks down and eventually disappear. This leads to a decrease in progesterone and estrogen, triggering menstruation.