Which cells of the seminiferous tubules provide nourishment and form the blood-testis barrier?

• A. Leydig cells
• B. Sertoli cells
• C. Germ cells
• D. Peritubular myoid cells

Answer: (B)

Sertoli cells are the sustentacular cells inside the seminiferous tubules that do two essential things for spermatogenesis. They provide direct nourishment and metabolic support to the developing germ cells, supplying nutrients and creating a specialized microenvironment in which spermatogenic cells can mature. They also form the blood-testis barrier by connecting with each other through tight junctions, creating basal and adluminal compartments that shield developing germ cells from blood-borne immune factors. This barrier is crucial to prevent immune reactions against sperm antigens that would otherwise be recognized as foreign. Leydig cells sit in the interstitial tissue and produce testosterone; germ cells are the developing sperm; peritubular myoid cells help with structural integrity and tubule movement but do not form the barrier or nourish like Sertoli cells.