The blood-testis barrier (abbreviated as BTB) is a physical barrier between the blood vessels and the seminiferous tubules of the animal testes.
The barrier is formed by tight connections between the Sertoli cells, which are sustentacular cells (supporting cells) of the seminiferous tubules, and nourish the spermatogonia.
The barrier avoids passage of cytotoxic agents (bodies or substances that are toxic to cells) into the seminiferous tubules.
The blood-testes barrier can be damaged by trauma to the testes (including torsion or impact), by surgery or as a result of vasectomy. When the blood-testes barrier is breached, and sperm enters the bloodstream, the immune system mounts an autoimmune response against the sperm. The anti-sperm antibodies generated by the immune system can bind to various antigenic sites on the surface of the sperm. If they bind to the head, the sperm may be less able to fertilize an egg, and if they bind to the tail, the motility of the sperm can be reduced.
|Male reproductive system|
|Scrotum||layers (skin, Dartos, External spermatic fascia, Cremaster/Cremasteric fascia, Internal spermatic fascia) • Perineal raphe • Spermatic cord|
|Testes||layers (Tunica vaginalis, Tunica albuginea, Tunica vasculosa testis) • Appendix • Mediastinum • Lobules • Septa • Leydig cell • Sertoli cell • Blood-testis barrier|
|Spermatogenesis||Spermatogonium • Spermatocytogenesis • Spermatocyte • Spermatidogenesis • Spermatid • Spermiogenesis • Spermatozoon|
|seminal tract||Seminiferous tubules (Tubuli seminiferi recti, Rete testis, Efferent ducts) • Epididymis (Appendix) • Vas deferens (Ampulla) • Ejaculatory duct|
|urinary tract||Internal urethral orifice • Urethra (Prostatic, Intermediate, Spongy, Navicular fossa) • External urethral orifice|
|accessory glands||Seminal vesicles (Excretory duct of seminal gland) • Prostate (Urethral crest/Seminal colliculus/Prostatic utricle/Ejaculatory duct, Prostatic sinus/Prostatic ducts) • Bulbourethral glands|
|Penis||root (Crus, Bulb, Fundiform ligament, Suspensory ligament) • body (Corpus cavernosum, Corpus spongiosum) • glans (Foreskin, Frenulum, Corona) • fascia (superficial/subcutaneous, deep/Buck's) • Tunica albuginea - Septum of the penis|