What is the function of the corpus luteum?

The corpus luteum plays a crucial role in the menstrual cycle and early pregnancy by secreting progesterone, which is essential for maintaining the uterine lining. After ovulation, the ruptured follicle transforms into the corpus luteum, which produces progesterone in response to luteinizing hormone (LH) secreted by the pituitary gland. This hormone helps prepare the endometrium (the inner lining of the uterus) for potential implantation of a fertilized egg, ensuring a suitable environment for embryo development. If pregnancy occurs, the corpus luteum continues to produce progesterone until the placenta takes over this role; if pregnancy does not occur, the corpus luteum degenerates, leading to a drop in progesterone levels and the onset of menstruation.

The incorrect options highlight functions that do not align with the primary role of the corpus luteum. For example, while estrogen is indeed involved in the menstrual cycle, it is primarily secreted by developing follicles and not the corpus luteum for the purpose of stimulating ovulation. Additionally, testosterone production is not a function of the corpus luteum, nor is it directly involved in facilitating fertilization.