Which of the following correctly lists the stages of the uterine (menstrual) cycle in order?

• A. Proliferative phase, secretory phase, menstrual phase
• B. Menstrual phase, proliferative phase, secretory phase
• C. Menstrual phase, secretory phase, proliferative phase
• D. Secretory phase, menstrual phase, proliferative phase

Answer: (B)

Verified step by step guidance

1. Understand that the uterine (menstrual) cycle is divided into three main phases: menstrual phase, proliferative phase, and secretory phase. These phases correspond to changes in the endometrium of the uterus in response to hormonal fluctuations.
2. The menstrual phase is the first phase of the cycle, during which the endometrial lining is shed if pregnancy does not occur. This phase typically lasts about 3-7 days.
3. The proliferative phase follows the menstrual phase. During this phase, the endometrium begins to rebuild itself under the influence of estrogen produced by the ovaries. This phase prepares the uterus for potential implantation of a fertilized egg.
4. The secretory phase is the final phase of the cycle. During this phase, the endometrium becomes thicker and more vascularized under the influence of progesterone, which is secreted by the corpus luteum. This phase supports implantation and early pregnancy if fertilization occurs.
5. To correctly list the stages of the uterine cycle in order, arrange them as follows: menstrual phase, proliferative phase, secretory phase. This sequence reflects the natural progression of the cycle.