In the case of a specific the anxiety produced by the given stimulus or situation is typically disproportionate to the actual threat the stimulus or situation poses.

phobia

Explanation:

Phobia defined as irrational fear against something. The fear will cause anxiety feeling that make the threat feels much bigger than it should be.  (For example, some people have a phobia of insects, and will scream uncontrollable and sobbing every time they see one of them)

A person will determine a situation as dangerous or threatening based on their past experience. This will vary greatly, which make phobia can come from any condition.  Many phobias not comes from a dangerous or life-threatening condition but acquired from a really unpleasant memory.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.