North American Registry of Midwives (NARM) Practice Exam

What activity increases due to progesterone's presence during the luteal phase of the menstrual cycle?

1. Menstrual bleeding

2. Endometrial gland activity

3. Ovary contraction

4. Sperm maturation

The correct answer is: Endometrial gland activity

During the luteal phase of the menstrual cycle, progesterone is secreted primarily by the corpus luteum, which forms from the ruptured follicle post-ovulation. One of the key roles of progesterone is to prepare the endometrium (the uterine lining) for potential implantation of a fertilized egg. The presence of progesterone stimulates the endometrial glands to increase their activity, promoting the secretion of substances that create a supportive environment for a fertilized ovum. This change is crucial for the potential successful implantation and nourishment of an embryo. The increased activity of the endometrial glands leads to thickening of the uterine lining and enhances vascularization, ensuring that the uterine environment is hospitable for implantation. If fertilization does not occur, progesterone levels will drop, leading to the shedding of the endometrial lining and the onset of menstruation.