physiology of stress

Question 1

When does a state of stress exist?

Answer 1

When an imbalance exists between perceived demands and perceived coping resources

Question 2

chronic stress

Answer 2

stress that develops slowly and exists over an extended period of time

Question 3

acute stress

Answer 3

onset is severe and sudden

Question 4

define a stressor

Answer 4

refers to any event that causes a stress reaction in the body

Question 5

what do stressors include?

Answer 5

• environmental stressors (eg workplace)
• life events (such as illness/divorce)

Question 6

where does the stress response begin?

Answer 6

Brain

Question 7

Stress response

Answer 7

• 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

Question 8

amygdala

Answer 8

area of brain that contributes to emotional processing
- interprets images and sounds

Question 9

hypothalamus

Answer 9

area of brain that communicates with rest of body through NS so person has energy to flight/flee
- communicates through ANS

Question 10

Autonomic Nervous System (ANS)

Answer 10

controls involuntry body functions such as breathing, blood pressure, heartbeat

Question 11

what are the 2 components of ANS?

Answer 11

SNS and PNS
- Sympathetic nervous system
- paraysmpatheic nervous system

Question 12

SNS

Answer 12

triggers fight or flight response, providing body with a burst of energy to respond to percieved dangers

Question 13

PNS

Answer 13

promotes rest and digest response
calms body down after danger passes

Question 14

As epinephrine ciruclates thorugh the body it brings physiolgical changes. What are they?

Answer 14

• 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

Question 15

What does epinephrine tirgger the release of?

Answer 15

blood sugar (glucose) and fats from temp storage sites in body, nutrients flood bloodstream, supplying energy to body.

Question 16

What are the 2 body responses to stress?

Answer 16

SAM - sympatho-adrenomedullary axis
HPA - hypothalamic-pituitary-adrenal axis

Question 17

What is SAM response responsible for ?

Answer 17

acute stress

Question 18

what does the acute response aim at enabling?

Answer 18

people to escape danger
- has to be fast so used nerve impulses rather than hormones to rpoduce changes

Question 19

Aim of SAM

Answer 19

to provide oxygen and glucose to the skeletal muscles
- the muscles which enable us to fight or flight

Question 20

SAM pathway

Answer 20

stressor percieved
- hypothalalmus activates
- SNS
- causes adrenal medulla to release adrenaline into bloodstream
- prepares for fight or flight
- adrenaline and noradenaline increase heart rate and breathing rate
- blood circulation is redirected to skeletal muscles and digestions stops
- when stressor subsides - PNS activated
- heart and breathing rate decrease, digestion restarts and other functions back to normal level

Question 21

SAM evaluation

Answer 21

• men tend to respond to stress by fight or flight response women more likely to produce tend and befriend response. thought to be caused by higher level of oxytocin hormone in W than M. Gender influences the activation of SAM
• most studies on stress on men - cannot be generlised to W as gender influences response of stressors. however, psychologists assume fight or flight response apply to all - shows gender bias

Question 22

What is HPA responsible for?

Answer 22

chronic stress
- slower to produce a response but lasts for longer period

Question 23

what does the HPA axis consist of?

Answer 23

• hypothalamus
• pituitary gland
• adrenal gland

Question 24

HPA axis pathway

Answer 24

• Hypothalamus releases corticotropin
  releasing hormone (CRH), which
  travels to the
• Pituitary gland, triggering the release
  of adrenocorticotropic hormone
  (ACTH) which travel to the
• Adrenal glands prompting them to
  release cortisol (stress hormone)
  which then mobilises
• Glucose stored in the liver which
  provides a constant supply of energy –
  body stays revved up and on high
  alert.
• When threat passes, cortisol levels fall
  and parasympathetic nervous system
  kicks in

Question 25

What does the HPA axis rely on ?

Answer 25

A series of hormonal signals to keep SNS active

Question 26

What keeps the HPA axis activated?

Answer 26

chronic low levels of stress after a while has an effect on body that contributes to health prob associated with chronic stress

Question 27

What is GAS ?

Answer 27

General Adaptation Syndrome

Question 28

What does GAS describe?

Answer 28

the physiological changes the body automatically goes through when it responds to stress

Question 29

who developed GAS?

Answer 29

Selye 1936

Question 30

what are the 3 stages of GAS

Answer 30

- Alarm - resistance - exhaustion - the more stages body goes thoguh, the greater the rist of long-lasting negative effects

Question 31

What can prolonged stress impact?

Answer 31

physical and mental health

Question 32

GAS - alarm stage - incorporates HPA

Answer 32

- intial response to stress - body SNS branch of ANS activated by sudden release of hormones - SNS stimultes adrenal glands - triggers release of adrenaline and noradrenaline ->release causes physical symptoms eg increase in heart and breating rate, rise in blood pressure

Question 33

Accoridng to Selye, what happens to most of the symptoms of the alarm stage response?

Answer 33

disappear or are reversed in the next stage (resistance), then reappear in the final stage of exhaustion

Question 34

GAS - resistance stage

Answer 34

after initial reaction of stressor - Parasympathetic branch of ANS counteracts changes that stressful stimulus has produced and attempts to restore state of homeostasis - body tries to repair itself after intial stress shock - if stress no longer present, physical symp return to normal during stage - if stress cont for long time/doesn't reslove stress, body will never recieve clear signal to return to normal functioning levels - means will cont to secrete stress hormone and blood pressure remains high - prolonged stress that is not resolved leads to 3rd stage.

Question 35

What can prolonged levels of high stress cause?

Answer 35

- disturbances in the immune, digestive, cardiovascular, sleep, and reproductive systems. - You might have symptoms such as bowel issues, headaches, sleeplessness, sadness, frustration, irritability, and poor concentration

Question 36

GAS- exhaustion stage

Answer 36

- prolonged/chronic stress leads to exhaustion stage - enduring stressors withough relief drains phyiscial,emotional, and mental resources to the point where your body is no longer able to cope with stress.

Question 37

What are the signs that you are in the exhaustion stage?

Answer 37

fatigue, burnout and depression

Question 38

What are example of stressors that can trigger GAS?

Answer 38

- Daily stress (such as pressure at school, work, or at home relating to your family) - A sudden change in your life (such as losing a job, divorce, or illness) - Traumatic experiences (such as abuse, a major accident, and war)

Question 39

Cortisol

Answer 39

- provides body with glucose by tapping into reserves stored in liver. - energy help an ind fight/flee a stressor - anti-inflammatory role - leads to weakening of immune system by reducing prod of lymphocytes -> increases likelihood of infections - constricts blood vessels and increases blood pressure to enhance the delivery of oxygenated blood. This is advantageous for fight-or-flight situations but over time, such arterial constriction and high blood pressure can lead to vessel damage and plaque build-up, this can lead to cardiovascular disorders.

Question 40

Evidence for Physiology of Stress

Answer 40

- **Perira et al (2003)** carried out a study on HIV posiive women comparing women who experienced high chronic stress and those who did not. One year later those with high stress were more likely to have developed pre-cancerous lesions of the cervix. However, this was not a representative sample (HIV weakens the immune system significantly). The link between stress and cancer is weak and difficult to establish. - **Kiecolt-Glaser et al. (1984)** investigated whether stress of important examinations has an effect on the functioning of the immune system.A volunteer sample was used: 75 American medical students. She took a blood sample from Ps 1 month before an important exam (low stress) and during the exam (high stress). The NK cells activity was measured.the NK cells activity was lower in the second sample (high stress). This was particularly true for those Ps who a high score on life events and reported feeling lonely. **Yusuf et al. (2004)** carried out a study of patients who had suffered heart attacks. They found that, although lifestyle factors such as smoking were influential, stress including workplace stressors and life events had a significant impact on the rate of heart attacks.

Question 41

Evaluation of physiology of stress

Answer 41

- difficulties with measuring stress. This is usually done using questionnaires and the answers could be affected by social desirability. - done on humans was natural experiments or correlational studies. There was no control of extraneous variables such as lifestyle e.g., smoking, lack of exercise or poor diet; therefore, we cannot establish a causal link between stress and immunosuppression or the incidence of cardiovascular disorders. - ethnocentric - carried out in western countries. don't know if other cultures respond in same way. - given knowledge of the possible effects of stress on health has been publicised and has raised the awareness of the general public, it has led some people to take action to prevent these problems from developing