A couple undergoes evaluation for male factor infertility. The husband asks how long it takes from the start of spermatogenesis until mature spermatozoa appear in the ejaculate. The correct answer includes the time taken for transit through which structure, where sperm acquire motility?

• A Rete testis
• B Vas deferens
• C Seminal vesicle
• D Epididymis ✓

Explanation

Spermatogenesis takes approximately 64 to 74 days, followed by about 2 weeks of epididymal transit, giving a total of roughly 90 days from germ cell entry into meiosis to appearance in semen. The epididymis is where sperm gain progressive motility and fertilising capacity through changes in membrane lipids and surface proteins. The rete testis and vas deferens are purely transport conduits, and the seminal vesicle contributes fluid after sperm have already left the testis.

Reference: Ganong's Review of Medical Physiology, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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