Which hormone does the hypothalamus release to start the menstrual cycle?

Which hormone does the hypothalamus release to start the menstrual cycle?

• A. FSH
• B. LH
• C. GnRH
• D. Progesterone

Answer: (C)

GnRH, gonadotropin-releasing hormone, is released by the hypothalamus to start the menstrual cycle. It sets the whole cascade in motion by signaling the anterior pituitary to release the gonadotropins FSH and LH. Those hormones then act on the ovaries to recruit follicles and trigger ovulation, guiding the cycle forward. Progesterone is produced after ovulation by the corpus luteum and helps prepare the uterine lining, but it doesn’t initiate the cycle. So the initiating signal from the hypothalamus is GnRH.

GnRH, gonadotropin-releasing hormone, is released by the hypothalamus to start the menstrual cycle. It sets the whole cascade in motion by signaling the anterior pituitary to release the gonadotropins FSH and LH. Those hormones then act on the ovaries to recruit follicles and trigger ovulation, guiding the cycle forward. Progesterone is produced after ovulation by the corpus luteum and helps prepare the uterine lining, but it doesn’t initiate the cycle. So the initiating signal from the hypothalamus is GnRH.