North Africa, region of Africa comprising the modern countries of Morocco, Algeria, Tunisia, and Libya. North AfricaEncyclopÃ¦dia Britannica, Inc.The geographic entity North Africa has no single accepted definition.
A Stressor is anything (physical or psychological) that produces stress (negative or positive) is considered a stressor.
effector. 1  A muscle, gland, or organ capable of responding to a stimulus, especially a nerve impulse. 2  A nerve ending that carries impulses to a muscle, gland, or organ and activates muscle contraction or glandular secretion.