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.
Stimulus and Response. Organisms detect changes in their environment and respond to these changes in a variety of ways. These changes may occur at the cellular or organism level. The graphic above shows the response of a human to being struck on the knee with a hammer. A change in the environment is called a stimulus.