Which one of the following is the most likely root cause why menstruation is not taking place in regularly…

Which one of the following is the most likely root cause why menstruation is not taking place in regularly cycling human female ?
  1. Retention of well-developed corpus luteum
  2. Fertilization of the ovum
  3. Maintenance of the hypertrophical endometrial lining
  4. Maintenance of high concentration of sexhormones in the blood stream

Solution

When fertilization occurs, the fertilized egg (embryo) releases human chorionic gonadotropin (hCG), which prevents the degeneration of the corpus luteum. As a result, the corpus luteum continues to secrete progesterone, which maintains the endometrial lining and prevents menstruation. Menstruation does not take place during pregnancy because the hormonal environment is altered to support the developing fetus.

Asked in: NEET 2009 (Mains)

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