During the last 14 days of a normal menstrual cycle, which phase occurs in the uterus?

During the last 14 days of a normal menstrual cycle, the uterus is in the secretory luteal phase. This phase occurs after ovulation when the corpus luteum forms and begins to produce progesterone, along with some estrogen. The primary function of progesterone during this phase is to prepare the endometrium (the lining of the uterus) for potential implantation of a fertilized egg. The endometrial lining becomes more vascularized and glandular in nature, providing the necessary environment for an embryo to implant and grow.

The secretory phase is characterized by the secretion of substances that support embryo implantation and nourishment if conception occurs. A rise in progesterone levels during this phase inhibits further release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), preventing the maturation of new follicles.

Other phases mentioned in the options refer to different points in the menstrual cycle. The proliferative phase occurs in the first half of the cycle and is influenced primarily by estrogen released from the developing follicles. In contrast, the secretory phase is distinct because of its reliance on the hormonal influences post-ovulation, particularly progesterone produced by the corpus luteum. This context helps underscore why the option indicating the uterus is in the secret