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.
1 Definition of stress - A stress is defined as a force per unit area, acting on an infinitesimal surface element. 2  Stresses have both magnitude (force per unit area) and direction, and the direction is relative to the surface on which the stress acts.  There are normal stresses and tangential stresses.