EEG See electroencephalogram. effector(ue-fek??tor) An organ, such as a gland or muscle, that responds to a motor stimulation. efferent (ef??er-ent) Conveying away from the center of an organ or structure. efferent arteriole (ar-tir??e-=ol) An arteriole of the renal vascular system that conducts blood away from the glomerulus of a nephron. efferent ductules (duk??toolz) A series of coiled tubules