Which hormone is responsible for converting the Graafian follicle to a corpus luteum?

The hormone responsible for converting the Graafian follicle into a corpus luteum is luteinizing hormone (LH). Once ovulation occurs, LH plays a crucial role in signaling the remnants of the Graafian follicle to transform into the corpus luteum. This structure is vital as it produces hormones, particularly progesterone, which are essential for maintaining the uterine lining and supporting early pregnancy if fertilization occurs.

LH acts as a key trigger in the reproductive cycle, initiating the final maturation of the follicle and the subsequent transformation into the corpus luteum. In contrast, the other hormones listed have different functions; for example, follicle-stimulating hormone (FSH) is primarily involved in the growth and maturation of ovarian follicles rather than their transformation post-ovulation. Oestrogen and progesterone, while critical in regulating the menstrual cycle and supporting pregnancy, do not directly induce the conversion of the Graafian follicle into the corpus luteum. Thus, LH is the definitive hormone for this process.