North American Registry of Midwives (NARM) Practice Exam

What hormone stimulates the increased activity of the endometrial glands during the luteal phase of the female reproductive cycle?

1. Estrogen

2. Progesterone

3. Testosterone

4. FSH

The correct answer is: Progesterone

During the luteal phase of the female reproductive cycle, progesterone plays a crucial role in preparing the endometrium for potential implantation of a fertilized egg. After ovulation, the corpus luteum forms and secretes progesterone, which stimulates the endometrial glands to become more active. This leads to the secretion of a nutrient-rich environment in the endometrium, providing essential support for an embryo should conception occur. The increase in gland activity is key for maintaining the uterine lining and creating suitable conditions for implantation. If pregnancy does not occur, progesterone levels drop, leading to the shedding of the endometrium, which is what happens during menstruation. Thus, the fundamental role of progesterone in this phase supports a preparation for both the possibility of pregnancy and the eventual menstruation if it does not occur.