Vasa efferentia are fine ciliated ductules that arise from the seminiferous tubules of the testis (where sperms are formed) and open into epididymis which is a mass of long narrow closely coiled tubule lying along the inner side of testis. Epididymis stores the sperms. Thus, if vasa efferentia gets blocked, sperms will not be transported from testis to the epididymis.