physiology of stress Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

When does a state of stress exist?

A

When an imbalance exists between perceived demands and perceived coping resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

chronic stress

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

acute stress

A

onset is severe and sudden

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define a stressor

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what do stressors include?

A
  • environmental stressors (eg workplace)
  • life events (such as illness/divorce)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where does the stress response begin?

A

Brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Stress response

A
  • 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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

amygdala

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hypothalamus

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Autonomic Nervous System (ANS)

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the 2 components of ANS?

A

SNS and PNS
- Sympathetic nervous system
- paraysmpatheic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

SNS

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

PNS

A

promotes rest and digest response
calms body down after danger passes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

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

A
  • 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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does epinephrine tirgger the release of?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 body responses to stress?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is SAM response responsible for ?

A

acute stress

18
Q

what does the acute response aim at enabling?

A

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

19
Q

Aim of SAM

A

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

20
Q

SAM pathway

A

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

21
Q

SAM evaluation

A
  • 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
22
Q

What is HPA responsible for?

A

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

23
Q

what does the HPA axis consist of?

A
  • hypothalamus
  • pituitary gland
  • adrenal gland
24
Q

HPA axis pathway

A
  • 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
25
Q

What does the HPA axis rely on ?

A

A series of hormonal signals to keep SNS active

26
Q

What keeps the HPA axis activated?

A

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

27
Q

What is GAS ?

A

General Adaptation Syndrome

28
Q

What does GAS describe?

A

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

29
Q

who developed GAS?

A

Selye 1936

30
Q

what are the 3 stages of GAS

A
  • Alarm
  • resistance
  • exhaustion
  • the more stages body goes thoguh, the greater the rist of long-lasting negative effects
31
Q

What can prolonged stress impact?

A

physical and mental health

32
Q

GAS - alarm stage - incorporates HPA

A
  • 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
33
Q

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

A

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

34
Q

GAS - resistance stage

A

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.

35
Q

What can prolonged levels of high stress cause?

A
  • 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
36
Q

GAS- exhaustion stage

A
  • 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.
37
Q

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

A

fatigue, burnout and depression

38
Q

What are example of stressors that can trigger GAS?

A
  • 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)
39
Q

Cortisol

A
  • 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.
40
Q

Evidence for Physiology of Stress

A
  • 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.

41
Q

Evaluation of physiology of stress

A
  • 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