Chapter 12

Stress

Short Term Stress

• A response of the brain (Sympathetic)

• Immediate action is necessary

• Or anticipation that immediate action is necessary

Acute Stress Response

Changes is blood distribution

Mobilization of sugar and fat

Long Term Stress

• Prepare the body for continued action

• Increases the capacity of the system to make immediate stress responses– Replaces sugar in liver– Alters use of energy substrates by tissues other

than the brain– Limits immune damage

Hypothalmic/Pituitary/adrenal axis:

Glucocorticoids

Stress: Not all or nothing

Stress

Stress

Stress

Stress

Stress

Stress Responses

• Development of increased capacity is dependent on the full response– Activation– Action– Long term stress to increase capacity

Incomplete Response

Variations in Stress Responses

• Cold Stress

• Starvation

• Learned Stress

Stress and Disease

• Chronic alert: Preparation for action followed by inaction

• Problems– Immunosuppression– Fat mobilization– Insulin resistance

Dealing with Stress

• Exercise

• Drugs