To change behavior or actions in response to outside conditions 4 Letters. What is the word?

The four-letter word which speaks to the ability of an organism to modify its behavior or actions to external stimuli is Move.

Explanation:

Movement gives organisms the ability to move away from or towards an external stimulus depending on whether it is a detrimental stimulus or a favourable one.

Examples of stimuli are:

Cheers

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .