Exhaustion The parasympathetic nervous system returns our physiological state to normal. We
can be more vulnerable to disease in this stage especially if our resources were
depleted by an extended resistance stage.Seyle’s model explains some of the documented problems associated with extended periods of stress.
Excessive stress can contribute to both physical diseases, such as some forms of ulcers and heart
conditions, and emotional difficulties, such as depression. Our bodies can remain ready for a challenge
only so long before our resources are depleted and we are vulnerable to disease due to exhaustion.
Perceived Control
Various studies show that a perceived lack of control over events exacerbates the harmful effects of
stress. Rats given control over the duration of electric shocks are less likely to get ulcers than rats without
this control even if both groups of rats receive the same amount of shock overall. A patient given control
over the flow of morphine will report better pain control than a patient given mandated levels of
morphine even though both patients get the same amount of morphine overall. Control over events tends to
lessen stress, while a perceived lack of control generally makes the event more stressful.