UPSC-CMS 2021 — Physiology

Q: A couple presented to OPD with complaint of inability to conceive for the last 3 years. Husband was advised semen analysis. What is the WHO criterion for minimum sperm count per ml in normal semen?

15 million. ***15 million*** - The **WHO 2010 criteria** for normal semen analysis specifies a lower reference limit for sperm concentration as **15 million spermatozoa per mL**. - This count is considered the minimum threshold for **normal fertility potential** according to current international guidelines. *30 million* - While a higher sperm count, **30 million** is not the minimum threshold set by the WHO for normal semen analysis. - A count of 30 million would be considered well within the normal range, but the question specifically asks for the *minimum* criterion. *40 million* - **40 million** is significantly above the minimum sperm concentration required for normal fertility as per WHO guidelines. - This higher count would indicate robust spermatogenesis but is not the lower limit for defining normalcy. *10 million* - A sperm count of **10 million spermatozoa per mL** falls below the **WHO 2010 reference range** for normal sperm concentration. - This value would likely be considered **oligozoospermia** and could indicate reduced fertility potential. [Practice more Physiology PYQs on OnCourse]

Q: The amount of iron lost per 28 day cycle in menstruating women is

15.5 mg. ***15.5 mg*** - The typical **iron loss** during a 28-day menstrual cycle in menstruating women is approximately **15-28 mg**, with an average of about **15.5 mg**. - This calculation is based on average menstrual blood loss of **30-40 mL per cycle** and iron content of approximately **0.5 mg per mL of blood**. - This physiological iron loss explains why menstruating women have **higher iron requirements** (18 mg/day) compared to men (8 mg/day). - If dietary iron intake is insufficient to compensate for this loss, **iron deficiency anemia** can develop over time. *5.5 mg* - This value significantly **underestimates** the actual iron loss during menstruation. - Such a low amount would not explain the increased iron requirements in menstruating women. - This does not align with measured menstrual blood loss volumes. *8.5 mg* - This value is still **lower than the typical physiological range** of iron loss during menstruation. - While closer than 5.5 mg, it underestimates the actual iron depletion that occurs. *12.5 mg* - This value is **within the lower range** but still below the commonly accepted average. - While individual variations exist, standard teaching emphasizes higher values (15-28 mg range). [Practice more Physiology PYQs on OnCourse]

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A couple presented to OPD with complaint of inability to conceive for the last 3 years. Husband was advised semen analysis. What is the WHO criterion for minimum sperm count per ml in normal semen?

The amount of iron lost per 28 day cycle in menstruating women is