1 A badge or insignia consisting of stripes meeting at an angle, worn on the sleeve of a military or police uniform to indicate rank, merit, or length of service. 2  n. Heraldry A device shaped like an inverted V.  n.
In physiology, a stimulus (plural stimuli) is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity.When a stimulus is applied to a sensory receptor, it normally elicits or influences a reflex via stimulus transduction.ne internal stimulus that causes hormone release is blood pressure. Hypotension, or low blood pressure, is a large driving force for the release of vasopressin, a hormone which causes the retention of water in the kidneys.
A stimulus can be internal or external. Sense organs, such as the ear, and sensory receptors, such as those in the skin, are sensitive to external stimuli such as sound and touch. Something that has an impact or an effect on an organism so that its behavior is modified in a detectable way. See more at classical conditioning.