physiology of stress Flashcards
When does a state of stress exist?
When an imbalance exists between perceived demands and perceived coping resources
chronic stress
stress that develops slowly and exists over an extended period of time
acute stress
onset is severe and sudden
define a stressor
refers to any event that causes a stress reaction in the body
what do stressors include?
- environmental stressors (eg workplace)
- life events (such as illness/divorce)
where does the stress response begin?
Brain
Stress response
- brain
- danger -> limbic system activated
- eyes/ears send info to amygdala
- percieved danger-> amygdala sends instant distress signal to hypothalamus
- hypthalamus com with rest of body through ANS - activates SNS by sending singnals through autonomic nerves to adrenal glands - glands pump epinephrine into blood
amygdala
area of brain that contributes to emotional processing
- interprets images and sounds
hypothalamus
area of brain that communicates with rest of body through NS so person has energy to flight/flee
- communicates through ANS
Autonomic Nervous System (ANS)
controls involuntry body functions such as breathing, blood pressure, heartbeat
what are the 2 components of ANS?
SNS and PNS
- Sympathetic nervous system
- paraysmpatheic nervous system
SNS
triggers fight or flight response, providing body with a burst of energy to respond to percieved dangers
PNS
promotes rest and digest response
calms body down after danger passes
As epinephrine ciruclates thorugh the body it brings physiolgical changes. What are they?
- heart beats faster than normal pushing blood to the muscle,heart and other vital organs
- pulse rate and blood pressure go up.
- breathes more rapidly
- airways open wide - take in as much O2 with each breath - extra O2 sent to brain - increases alertness
What does epinephrine tirgger the release of?
blood sugar (glucose) and fats from temp storage sites in body, nutrients flood bloodstream, supplying energy to body.
What are the 2 body responses to stress?
SAM - sympatho-adrenomedullary axis
HPA - hypothalamic-pituitary-adrenal axis