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.
We characterize stimulus in terms of the external cause and either the subjective experience or the behavioral response to which it gives rise or, in the case of noxious or non-noxious stimuli, in physiology, we could say that it is an external event or agent that gives rise to discharge in an afferent nervous system.