Physiology of chronic stress & HPA axis

Question 1

Stress is the body’s reaction to feeling threatened or under pressure. It has been acknowledged that it transcends across 3 main areas, what are they?

1 - Emotional, Environmental, Physiological
2 - Psychological, Environmental, Physiological
3 - Emotional, Psychological, Physiological
4 - Emotional, Environmental, Psychological

Answer 1

1 - Emotional, Environmental, Physiological

Question 2

When we talk about stress, is it always real?

Answer 2

• can be real
• can be imagined
• can be internal (spontaneous, unconsious)
• can be external (workplace, study)

Question 3

Significant life events that are associated with change have been identified as being quantifiable. Why would this be useful?

Answer 3

• identify those at risk of stress
• identify variables and reduce the risk of stress
• prevention is better than cure

Question 4

What is cognitive appraisal of stress?

Answer 4

• an individuals own interpretation of a specific situation
• decide if the situation is stressful or not is individual

Question 5

What is the Holmes-Rahe Stress Scale?

Answer 5

• 43 point tool
• used to measuring and assess life events
• gives a score for the amount of stress you’ve experienced within the past year

Question 6

There are reported to be different types of stress. What is positive/eustress?

Answer 6

• stress we feel when we get excited
• stress we get when responding to a challenge
• enhances self esteem and impulse control

Question 7

Positive/eustress is stress we feel when we get excited or when responding to a challenge that was stressful, which can all enhances self esteem and impulse control. Why is this good moving forward?

Answer 7

• learn that we can cope with the situation and stress
• if the situation arises again we know we can manage

Question 8

There are reported to be different types of stress. What is tolerable stress?

1 - stress that we are able to manage with the support of others (family, friends)
2 - positive stress that can enhance self esteem and impulse
3 - stress that cannot be managed due to poor coping strategies and/or lack of support
4 - stress that is always negative regardless of the stimulus of coping strategies

Answer 8

1 - stress that we are able to manage with the support of others (family, friends)
- enhances self esteem and impulse control
- means in future you can manage future stressors

Question 9

There are reported to be different types of stress. What is toxic stress?

1 - stress that we are able to manage with the support of others (family, friends)
2 - positive stress that can enhance self esteem and impulse
3 - stress that cannot be managed due to poor coping strategies and/or lack of support
4 - stress that is always negative regardless of the stimulus of coping strategies

Answer 9

3 - stress that cannot be managed due to poor coping strategies and/or lack of support

Question 10

Toxic stress can be from situations that an individual deems as a stressful experience based on their cognitive appraisal, where they have no support system available to help manage this. Why can this be dangerous?

Answer 10

• can lead to dysregulated physiological systems
• can compromise brain architecture

Question 11

What is the transactional model of stress?

1 - model processing stressful scenarios as transactions
2 - model emphasising cognitive appraisal (harm, threat, challenge)
3 - model demonstrating how to manage stress

Answer 11

2 - model emphasising cognitive appraisal (harm, threat, challenge)

Question 12

The transactional model of stress is a framework which emphasises appraisal to evaluate harm, threat and challenges. What does the first box in the figure relate to?

1 - primary appraisal, patient determines if stressor is manageable
2 - stimulus doesn’t move past cognitive appraisal
3 -stimulus to begin cognitive appraisal if something is stressful or not
4 - secondary appraisal, patient stimulus is stressful and must be processed

Answer 12

3 -stimulus to begin cognitive appraisal if something is stressful or not
- a stressor/life event/situation that we have to navigate through
- the type of event is not important, BUT the individuals perception is important (cognitive appraisal)

Question 13

The transactional model of stress is a framework which emphasises appraisal to evaluate harm, threat and challenges. Thew first box relates to a stressor/life event/situation that we have to navigate through. BUT it is not the specific event that matters, BUT the individuals perception (cognitive appraisal) of the situation. What does the second box relate to?

1 - primary appraisal, patient determines if stressor is manageable
2 - stimulus doesn’t move past cognitive appraisal
3 -stimulus to begin cognitive appraisal if something is stressful or not
4 - secondary appraisal, patient stimulus is stressful and must be processed

Answer 13

1 - primary appraisal, patient determines if stressor is manageable
- could essentially be positive/beneficial stress, irrelevant stress or could it be dangerous stress
- called tolerable stress

Question 14

The transactional model of stress is a framework which emphasises appraisal to evaluate harm, threat and challenges. Thew first box relates to a stressor/life event/situation that we have to navigate through. BUT it is not the specific event that matters, BUT the perception (cognitive appraisal) of the situation. If the stressor is perceived as positive or irrelevant, then we move to the second box. The second box, called secondary appraisal is when a patient has identified a stressor as risk. What 2 things can then happen from here?

Answer 14

1 - patient realises they have sufficient self control or a support circle to deal with situation. This is positive and a coping strategy
2 - patient realises they do not have sufficient self control or a support circle to deal with situation which then causes stress. This is negative and a similar/same stressor will cause stress in future
- both feed back into our experiences for future situations and stress

Question 15

Stress is not necessarily one instance, but rather what?

Answer 15

• ones critical appraisal of a situation
• lots of things can affect this

Question 16

What is the hypothalamic–pituitary–adrenal axis (HPA)?

Answer 16

• a complex set of direct influences and feedback interactions that is considered the stress axis
• 3 important parts (hypothalamus, pituitary and adrenal glands

Question 17

What is the pathway of the hypothalamic-pituitary–adrenal (HPA) axis without the hippocampus?

Answer 17

• hypothalamus secretes corticotropin-releasing hormone (CRH)
• CRH binds with pituitary gland
• pituitary glands secretes adrenocorticotropic hormone (ACTH)
• ACTH stimulates production and release of cortisol from the adrenal cortex (outer part) of the adrenal gland as glucocorticoid

Question 18

There is a bi-directional relationship hypothalamic–pituitary–adrenal axis (HPA) and what other system?

1 - cardiac system
2 - immune system
3 - musculoskeletal system
4 - skeletal system

Answer 18

2 - immune system

Question 19

There is a bi-directional relationship hypothalamic–pituitary–adrenal axis (HPA) and the immune system. What proteins are important for this bi-directional relationship?

1 - cytokines
2 - hormones
3 - RBCs
4 - lymphocytes

Answer 19

1 - cytokines

Question 20

The hypothalamic–pituitary–adrenal axis (HPA) is a complex set of direct influences and feedback interactions that is considered the stress axis, including 3 important parts (hypothalamus, pituitary and adrenal glands). It also works in a bi-directional relationship with the immune system, which is modulated by cytokines. What hormone released by the adrenal cortex, in high levels can dampen the immune system and make us sick?

Answer 20

• cortisol a steroid hormone
• released as glucocorticoid

Question 21

What is the normal pathway for the hypothalamic–pituitary–adrenal (HPA) axis?

Answer 21

• hypothalamus secretes corticotrophin (CRH) hormone
• CRH triggers pituitary gland to release adrenocorticotropic hormone (ACTH)
• ATCH simulates adrenal cortex to release cortisol as glucocorticoid

Question 22

What is the negative feedback loop of the hypothalamic–pituitary–adrenal (HPA) axis?

Answer 22

• cortisol released from adrenal cortex is packaged as glucocorticoids
• glucocorticoids can bind with glucocorticoids receptors in the hypothalamus
• once hypothalamus detects this it stops the starting process for the release of cortisol

Question 23

What is allosteric overload?

Answer 23

• cumulative burden of chronic stress on mental and physiological wellbeing
• stress is based on cognitive appraisal of how an individual perceives the situation

Question 24

What can happen during childhood that can increase the risk of allosteric overload (chronic stress that can result in physiological changes)?

Answer 24

• Adverse Childhood Experiences
• homelessness; displacement; migration; domestic abuse

Question 25

If someone experiences Adverse Childhood Experiences [ACE’s]; homelessness; displacement; migration; domestic abuse; etc, there is strong evidence of chronic stress induced changes within endocrine and immune system functionality, via the HPA axis. Will the dysfunction of the endocrine and immune system return to normal when the stress has stopped?

Answer 25

- possibly - also likely to persist once the stressor has been removed/resolved

Question 26

The hippocampus is involved in learning and memory. What can damage to the hippocampus cause? 1 - sensory changes 2 - cognitive, learning and memory impairment 3 - co-ordination problems 4 - chronic pain

Answer 26

2 - cognitive, learning and memory impairment - interferes within the process new learning (damages the dentate gyrus)

Question 27

What can happen to the volume of the hippocampus of adults and children who have experienced Adverse Childhood Experiences, such as homelessness; displacement; migration; domestic abuse?

Answer 27

- reduced volume - impaired memory

Question 28

How is increased cortisol levels involved in memory? 1 - hippocampus atrophy, cortisol stimulation and reduced rapid eye movement sleep 2 - hippocampus hypertrophy, cortisol excitotoxicity and reduced rapid eye movement sleep 3 - hippocampus atrophy, cortisol excitotoxicity and increased rapid eye movement sleep 4 - hippocampus atrophy, cortisol excitotoxicity and reduced rapid eye movement sleep

Answer 28

4 - hippocampus atrophy, cortisol excitotoxicity and reduced rapid eye movement sleep - can impair encoding and recall of memory - most memories are encoded/recalled during rapid eye movement (REM) sleep - REM sleep is reduced with elevated levels of cortisol - cortisol excitotoxicity to hippocampus causing atrophy

Question 29

Cortisol is not released from the adrenal cortex as cortisol. What is it released as?

Answer 29

- glucocorticoids - gluco = glucose - cortico = cortisol - oids = steroid

Question 30

Cortisol is not released from the adrenal cortex as cortisol. Instead it is released as glucocorticoids. - gluco = glucose - cortico = cortisol - oids = steroid Glucocorticoid binds with the hippocampus via the glucocorticoids receptors and forms part of the negative feedback loop for cortisol control. What happens? 1 - stimulates hippocampus that inhibits hypothalamus and reduces pituitary stimulation 2 - inhibits hippocampus that inhibits hypothalamus and reduces pituitary stimulation 3 - stimulates hippocampus that stimulates hypothalamus and increases pituitary stimulation 4 - stimulates hippocampus that inhibits hypothalamus and reduces pituitary stimulation

Answer 30

4 - stimulates hippocampus that inhibits hypothalamus and reduces pituitary stimulation

Question 31

What is allostosis? 1 - adapting to change, specifically stress 2 - binding of a drug to a different part of a receptor 3 - rejecting change based on stressors

Answer 31

1 - adapting to change, specifically stress

Question 32

Allostosis is the ability to adapt to change, specifically stress, if this cannot be done effectively we enter allostatic overload. What is allostatic overload?

Answer 32

- cumulative burden of chronic stress - can affect the body physiologically - stress is based on cognitive appraisal of how an individual perceives the situation

Question 33

What is acute stress?

Answer 33

- cognitive appraisal determines something is stressful - stress triggers the fight of flight response - release of noradrenalin and adrenalin

Question 34

In acute stress, which is cognitive appraisal that has determined something is stressful. The stress then triggers the fight of flight response and release of noradrenalin and adrenalin. Does this stress and physiological stimulus then persist once the stimulus for the stress has been removed?

Answer 34

- no - acute stress only persists during the stressful event

Question 35

In acute stress, which is cognitive appraisal that has determined something is stressful. The stress then triggers the fight of flight response and release of noradrenalin and adrenalin. Once the stimulus for the stress has been removed how is the acute stress stopped and return to a normal physiological state?

Answer 35

- negative feedback loop of hypothalamus - glucocorticoid binds to hypothalamus - hypothalamus down regulates the pituitary gland