What is the significance of the human testes being located in scrotal sacs outside the abdomen?

Sperm formation requires a temperature about 2–3°C LOWER than the normal body temperature. By hanging outside the abdominal cavity in the scrotal sacs, the testes are kept cooler than the rest of the body, which is essential for the production of healthy sperms.

The answer turns on one fact — the TEMPERATURE requirement — and giving the figure (2–3°C below body temperature) makes it precise.

THE EVIDENCE that this is the reason: if a testis fails to descend into the scrotum and remains in the abdomen (a condition called CRYPTORCHIDISM), it cannot produce sperms at all, and the man is sterile unless it is corrected surgically.

So the position of the scrotum is not an accident of anatomy but a requirement of physiology — which is exactly the kind of structure-and-function link examiners look for.

Note that the testes descend through the INGUINAL CANAL shortly before birth, which the 2025 paper asks about directly.