Final answer:
The initial stage of general adaptation syndrome that temporarily lowers resistance is called the alarm reaction stage, characterized by the fight-or-flight response.
Step-by-step explanation:
The stage of general adaptation syndrome when the body initially responds with changes that temporarily lower resistance is called the alarm reaction stage. During this stage, the body experiences a sudden activation of its stress responses, sometimes known as the fight-or-flight response.
This response is characterized by the secretion of stress hormones such as epinephrine and norepinephrine, which prepare the body for immediate physical action. If the stress is not relieved, the body will adapt and enter the stage of resistance, where the initial shock has worn off, but the body remains on alert and prepared to respond to stressors, albeit with less intensity.