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. (Stimuli also means to stimulate). 


Stimuli is also is responsible for exciting and stimulating the neurones in the human body (something that incites to action or quickens action, feeling, thought, etc).


Stimuli is a presence of energies which surrounds our environment, affecting the body via smell, sight, feeling and pineal gland. Stimuli can be categorized into two categories. 


There is a stimuli which comes from physical or scientific energies, and there is another type of stimuli which comes from the spirits or spiritual presence. 

When a stimulus is applied to a sensory receptor, These sensory receptors can receive information from outside the body, as in subliminal information, sexual energy or spiritual presence, and in the body this stimuli is converted to electrical and chemical signals. 

External stimuli are capable of producing systemic responses throughout the body, which has the ability to move the human body into the behavior of acting or reacting.


In order for a stimulus to be detected with high probability, its level must exceed the absolute threshold; if a signal does reach threshold, the information is transmitted to the central nervous system (CNS), where it is integrated and a decision on how to react is made. 

Although stimuli commonly cause the body to respond, the CNS makes the final decision whether a signal warrants a reaction or not.