Editing Testicle (section)

====The blood–testis barrier====
{{main|Blood–testis barrier}}
Large molecules cannot pass from the blood into the lumen of a seminiferous tubule due to the presence of [[tight junction]]s between adjacent Sertoli cells.<ref name="Steger 2">{{Cite book|last1=Steger|first1=Klaus|last2=Weidner|first2=Wolfgang|title=Practical Urology: Essential Principles and Practice|chapter=Anatomy of the Male Reproductive System|chapter-url=https://books.google.com/books?id=A9m8TkdCUqEC&pg=PA63|date=2011|publisher=Springer Science & Business Media|isbn=978-1-84-882034-0|page=63|access-date=2022-06-05|archive-date=2023-06-29|archive-url=https://web.archive.org/web/20230629160505/https://books.google.com/books?id=A9m8TkdCUqEC&pg=PA63|url-status=live}}</ref> The spermatogonia occupy the basal compartment (deep to the level of the tight junctions) and the more mature forms, such as primary and secondary spermatocytes and spermatids, occupy the adluminal compartment.<ref name="Steger 2"/>

The function of the blood–testis barrier may be to prevent an [[auto-immune]] reaction.<ref name="Steger 2"/> Mature sperm (and their [[antigen]]s) emerge significantly after immune tolerance is set in infancy.<ref name="Steger 2"/> Since sperm are antigenically different from self-tissue, a male animal can react immunologically to his own sperm. The male can make antibodies against them.<ref name="Steger 2"/>

Injection of sperm antigens causes inflammation of the testis (auto-immune orchitis) and reduced fertility.<ref name="Steger 2"/> The blood–testis barrier may reduce the likelihood that sperm proteins will induce an immune response.<ref name="Wiser">{{Cite book|last1=Wiser|first1=Herbert J.|last2=Sandlow|first2=Jay|last3=Kohler|first3=Tobias S.|title=Male Infertility: Contemporary Clinical Approaches, Andrology, ART & Antioxidants|chapter=Causes of Male Infertility|chapter-url=https://books.google.com/books?id=W8pplg2vbEUC&pg=PA8|date=2012|publisher=Springer Science & Business Media|isbn=978-1-46-143335-4|page=8|access-date=2022-07-10|archive-date=2023-06-29|archive-url=https://web.archive.org/web/20230629160509/https://books.google.com/books?id=W8pplg2vbEUC&pg=PA8|url-status=live}}</ref>