What is Stress? Strain that experienced when an organism’s equilibrium is disrupted
There is a stressor (source of stress) such as a dog, and the stress reaction (bunny’s physical and emotional response). Stress is the process encompassing both.
Stress arises less from actual events & more from our cognitive interpretation of events – appraisal theory of stress.
Primary appraisal – evaluating for presence of a potential threat.
3 categories of response to this primary appraisal – irrelevant, benign (positive), stressful (negative).
If primary appraisal is negative, move forward with secondary appraisal.
Secondary appraisal – assessing capability to cope with the threat or to deal with stressor.
Appraisal of harm, threat, and challenge (how to overcome it).
4 major categories of stressors.
Significant life changes – ex. Death of loved one, loss of job, having children, leaving home, etc.
Catastrophic events – cyclone appears.
Daily hassles – long store lines, forgetting car keys, etc.
Ambient stressors – Perceivable, but hard to control. Noise, crowding. Can impact us without us being aware of them.
Responding to Stress
The ANS works with the limbic system and reticular activating system to allow us to experience and understand our emotions
Reticular activating system – nuclear structures in the midbrain composed of nerve fibers going to and from higher brain centers, which controls our arousal and alertness levels
Midbrain – cerebral peduncle, corpora qudrigemina, and cerebral aqueduct
Stressors like threats and dangers trigger our fight or flight system – the sympathetic nervous system.
heart rate and respiration (more energy + oxygen), increased peripheral vasoconstriction (push more blood to our core area – harder to live without blood), and turn off digestion/immune/etc.
Endocrine response – adrenal glands release epinephrine and norepinephrine, and cortisol
Tend and befriend response – sometimes better response to stress is to have support systems.
Oxytocin is important for this – peer bonding. Oxytocin is strongly linked to estrogen, so why this response is stronger in women.
Distinct stages of stress – general adaptation syndrome, 3 phases.
Alarm phase – stress kicks in, heart races.
Resistance – fleeing, huddling, etc. Bathed in cortisol.
Exhaustion – if resistance isn’t followed by recovery, our tissues become damaged and we become susceptible to illness.
Physical Effects of Stress
Damaging effects of stress on our heart
Increased blood pressure, blood vessels distend, so they build up more muscle and become more rigid. Can lead to hypertension and vascular disease (disease of blood vessels – get damaged with higher force of blood movement). Spots attract fat and narrow blood vessels. Worst place to experience this is coronary arteries – coronary artery disease.
During stress, body secretes cortisol and glucagon, which converts glycogen to glucose.
If stress is psychosocial, we don’t need all this extra glucose, which can exacerbate metabolic conditions like diabetes.
Reproduction huge energy expense in women, so this gets shut down during stress response. Impotence is also often caused by stress.
Causes inflammation – acute stress can lead to overuse of immune system. Can attack our own body.
Behavioral Effects of Stress
2 areas of brain with most glucocorticoid receptors are the hippocampus and frontal cortex
Hippocampus is associated with learning and memory.
Frontal cortex is responsible for impulse control, reasoning, etc. Atrophy during chronic stress.
One of major emotional responses of stress is depression (problem is anhedonia – inability to experience pleasure, so perceive more stressors).
Learned helplessness – you learn from having control ripped out of hands that you don’t have control, so lose ability to identify coping mechanisms because taking less control of outcome of your life.
Anger – Stress is associated with increased vulnerability to heart disease. Type A is easily angered individuals, and Type B others. Those who had heart attacks later were mostly type A.
Anxiety – centers on amygdala. Amygdala has to do with our fears and phobias, fits in perfectly with response to stress. Perceive more things as fearful.
Addiction – lots of terrible options for relieving stress, ex. Alcohol, tobacco, etc. Impairment to frontal cortex (reasoning), so impaired judgement can increase likelihood of inappropriate coping mechanisms.
Stress Management (Coping with Stress)
Perceived control – many studies show lack of control associated with higher stress. Look for areas of life where you can take back some control.
Social support – one of best coping mechanisms of stress. Helps us understand we’re not alone in stress, which helps our perceived control and optimism.
Exercise – regular exercise requires control
Meditation – helps us lower our heart rate, BP, and cholesterol.
Religious beliefs/faith – generally healthier lifestyle, social support.
Cognitive Flexibility – perspective change is huge in our perception of what is stressing us out. Good way is working with counselor.