In males, the blood-testis barrier (BTB) is essential for immunological privilege of the testis. The BTB is formed by tight junctions between:

• A Peritubular myoid cells surrounding the seminiferous tubule, forming a physical barrier to immune cell infiltration
• B Adjacent Sertoli cells, creating a luminal compartment where meiotic and post-meiotic germ cells are sequestered from the immune system ✓
• C Leydig cells and perivascular smooth muscle cells surrounding testicular capillaries
• D Spermatogonia and primary spermatocytes forming gap junctions that prevent immune cell penetration

Explanation

The blood-testis barrier is formed by specialized tight junctions (including occludin, claudins, and junctional adhesion molecules) between adjacent Sertoli cells within the seminiferous epithelium. These junctions divide the seminiferous tubule into a basal compartment (accessible to the immune system, containing spermatogonia and early spermatocytes) and an adluminal compartment (immunologically privileged, containing meiotic and post-meiotic germ cells). This is essential because haploid spermatocytes and spermatids express novel antigens that would trigger autoimmune orchitis if exposed to the systemic immune system — their isolation as 'self' antigens does not occur since the BTB forms during puberty after immune tolerance is established.

Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.