Where are Leydig cells located?

• A. In the lumen of seminiferous tubules
• B. In the epididymis
• C. Between Sertoli cells
• D. In the interstitial tissue of the testis

Answer: (D)

Leydig cells are the testosterone-secreting cells of the testis and reside in the interstitial tissue between the seminiferous tubules. They cluster around blood vessels in this connective tissue, outside the tubular lining where germ cells and Sertoli cells are found. This outside-tubule location is what sets them apart from cells inside the tubules or in ducts like the epididymis. Histologically, they’re large, with eosinophilic cytoplasm rich in smooth endoplasmic reticulum and lipid droplets, reflecting their steroid-producing function.