Sources of extracellular vesicles within the male reproductive tract. Given that the secretion of extracellular vesicles (EVs) is a virtually ubiquitous property of all cell lineages, it appears likely that tissues across the male reproductive tract will produce EVs. While best characterized in the prostate and epididymis, evidence suggests that testis, seminal vesicles, and vas deferens produce populations of EVs that currently have unknown functions. Remarkably, EV populations originating beyond the male reproductive tract may exert influence on reproductive function and are postulated to act as messengers of lifetime experience.