Final answer:
Increases in heart rate, blood pressure, perspiration, and blood sugar are detected during the alarm reaction stage of the general adaptation syndrome, which is the initial stress response.
Step-by-step explanation:
The increases in heart rate, blood pressure, perspiration, and blood sugar would be detected during the alarm reaction stage of the general adaptation syndrome. This phase represents the body's immediate reaction to a stressor, commonly referred to as the fight-or-flight response.
In the alarm reaction stage, stress hormones like epinephrine and norepinephrine are secreted, preparing the body for action. If the stressor persists, the body then enters the stage of resistance, where the initial shock has worn off, and the body adapts while remaining on alert. However, it's the initial alarm reaction where the acute physiological responses such as increased heart rate and perspiration are most pronounced.