What is a stimulus?jh

In physiology, a stimulus is a detectable change in the physical or chemical structure of an organism's internal or external environment. The ability of an organism or organ to detect external stimuli, so that an appropriate reaction can be made, is called sensitivity.

In general, a stimulus is something that provokes or causes an action or response, as in Failing that test was the stimulus I needed to start studying harder. The plural of stimulus is stimuli. In the context of science, a stimulus is anything that makes an organism or a part of an organism react in some way.

have a good day/night  may i please have a brainlliest

Explanation:

A stimulus is anything that can trigger a physical or behavioral change. The plural of stimulus is stimuli. .An example of external stimuli is your body responding to a medicine. An example of internal stimuli is your vital signs changing due to a change in the body