Which structure maintains a lower body temperature necessary for sperm survival?

Which structure maintains a lower body temperature necessary for sperm survival?

• A. Scrotum
• B. Penis
• C. Epididymis
• D. Testes

Answer: (A)

Keeping sperm viable requires a cooler environment than the body's core temperature. The scrotum provides a pouch outside the body where the testes reside, keeping them about 2–3°C cooler. It achieves this with muscle actions (the cremaster and dartos muscles) that adjust the testicular position and tighten the scrotal skin, plus a network of veins called the pampiniform plexus that cools arterial blood before it reaches the testes through countercurrent heat exchange. The penis is involved in sexual function but not temperature regulation, the epididymis matures and stores sperm, and the testes produce sperm but do not regulate temperature themselves. Thus, the scrotum is the structure that maintains the lower temperature necessary for sperm survival.

Keeping sperm viable requires a cooler environment than the body's core temperature. The scrotum provides a pouch outside the body where the testes reside, keeping them about 2–3°C cooler. It achieves this with muscle actions (the cremaster and dartos muscles) that adjust the testicular position and tighten the scrotal skin, plus a network of veins called the pampiniform plexus that cools arterial blood before it reaches the testes through countercurrent heat exchange. The penis is involved in sexual function but not temperature regulation, the epididymis matures and stores sperm, and the testes produce sperm but do not regulate temperature themselves. Thus, the scrotum is the structure that maintains the lower temperature necessary for sperm survival.