Which phase of the endometrial cycle coincides with the luteal phase?
Menstrual phase
Proliferative phase
Secretory phase
Regenerative phase
The Correct Answer is C
The endometrial cycle aligns with the ovarian cycle and consists of three main phases: menstrual, proliferative, and secretory. The secretory phase coincides with the luteal phase of the ovarian cycle and spans approximately days 15–28. It is regulated primarily by progesterone (normal mid-luteal: 5–20 ng/mL) secreted by the corpus luteum. Progesterone stimulates the endometrial glands to secrete glycogen and other nutrients, making the endometrium thick, vascular, and receptive to implantation. Without fertilization, progesterone levels fall, leading to endometrial breakdown and the start of menstruation.
Rationale for correct answer
C. The secretory phase is driven by progesterone from the corpus luteum and prepares the endometrium for possible implantation. It occurs during the luteal phase of the ovarian cycle.
Rationale for incorrect answers
A. The menstrual phase coincides with the early follicular phase, not the luteal phase. It involves shedding of the functional layer of the endometrium due to hormone withdrawal.
B. The proliferative phase occurs during the follicular phase of the ovarian cycle. It is estrogen-driven and involves rebuilding the endometrium after menstruation.
D. The regenerative phase is not a standard term in the clinical classification of the endometrial cycle. The correct phases are menstrual, proliferative, and secretory.
Take home points
- The secretory phase matches the luteal phase and prepares the uterus for implantation.
- Progesterone from the corpus luteum drives the secretory changes.
- The proliferative phase aligns with follicular phase and is estrogen-dependent.
- Menstrual phase begins with hormone withdrawal and marks the end of the luteal phase.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is ["A","B"]
Explanation
The anterior pituitary secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH), two key gonadotropins that regulate the ovarian cycle and control the secretion of ovarian hormones (estrogen and progesterone). FSH (normal: 3–20 IU/L) promotes follicular growth and estrogen production during the follicular phase, while LH (normal: 5–20 IU/L) triggers ovulation and stimulates the formation and function of the corpus luteum during the luteal phase. Their secretion is stimulated by GnRH from the hypothalamus in a pulsatile manner.
Rationale for correct answers
A. FSH is secreted by the anterior pituitary and stimulates the growth and maturation of ovarian follicles and the synthesis of estradiol by granulosa cells.
B. LH is also released from the anterior pituitary and is responsible for triggering ovulation and maintaining the corpus luteum, which secretes progesterone during the luteal phase.
Rationale for incorrect answers
C. GnRH is not secreted by the anterior pituitary—it is secreted by the hypothalamus and acts on the anterior pituitary to stimulate the release of FSH and LH.
D. Estrogen is produced by granulosa cells of the ovarian follicles, not by the anterior pituitary. Its secretion is regulated by FSH.
E. Progesterone is secreted by the corpus luteum in the ovary after ovulation. It is not an anterior pituitary hormone.
Take home points
- FSH and LH are the two anterior pituitary hormones that regulate the menstrual cycle.
- GnRH is from the hypothalamus, not the anterior pituitary.
- Estrogen and progesterone are secreted by the ovaries under pituitary control.
- Pituitary hormones initiate and regulate ovulation and corpus luteum function.
Correct Answer is B
Explanation
The corpus luteum is formed from the ruptured ovarian follicle after ovulation and functions as a temporary endocrine gland, primarily secreting progesterone (5–20 ng/mL mid-luteal) and smaller amounts of estrogen. It maintains the endometrium in preparation for implantation. If fertilization and implantation do not occur, the absence of human chorionic gonadotropin (hCG) causes the corpus luteum to degenerate around day 24–26 of a typical 28-day cycle. It then becomes a fibrous scar tissue called the corpus albicans, leading to a drop in progesterone and estrogen levels, and triggering menstruation.
Rationale for correct answer
B. If fertilization does not occur, the corpus luteum degenerates due to lack of hCG support and transforms into the corpus albicans. This structural regression leads to hormonal withdrawal and menstruation.
Rationale for incorrect answers
A. Progesterone secretion continues only if fertilization occurs and hCG is produced by the trophoblast. Without hCG, the corpus luteum involutes and stops secreting hormones.
C. The corpus luteum forms after ovulation; it does not trigger it. Ovulation is triggered by the LH surge prior to corpus luteum formation.
D. The corpus luteum secretes some estrogen, but its primary function is progesterone production. After degeneration, it no longer produces either hormone in significant amounts.
Take home points
- The corpus luteum regresses into the corpus albicans without fertilization.
- Hormonal support from hCG is necessary to sustain the corpus luteum.
- Progesterone levels drop, triggering menstruation.
- The corpus luteum does not cause ovulation; it follows it.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.