These may be summarised as follows: maintenance of the blood-testis barrier by junctional complexes; nourishment of developing germ cells; phagocytosis of damaged germ cells; production of ABP, which is secreted by seminiferous tubules (ABP production is dependent upon FSH and testosterone action); production of tubular fluid to provide the major drive for flushing sperm from the testis to the epididymis; and production of inhibin and activin which control FSH secretion.
