Stress And Adaptation Flashcards
When does a person experience stress?
When a demand exceeds a persons coping abilities
What are 3 types of stressors?
Eustressors, distressesors or neutral
Where can stressors come from?
External environment or personal perception
What are quantity external stimuli?
Negative consequences due to accumulation
What are qualify external stimuli?
Major changes (large #of people), major change (few people), daily hassles
What are duration external stimuli?
Acute, sequential, chronic, intermittent
What are the 3 types of external stimuli?
Quantity, quality and duration
What is individual judgement?
Conscious appraisal, demand-resource imbalance
What hormones are involved in stress?
Glucocorticoid, mineralcorticoid and catecholamines
What glucocorticoid is involved in stress?
Cortisol
What mineralcorticoid is involved in stress?
Aldosterone
What catecholamines are involved in stress?
Epinephrine, norepinephrine and a little dopamine
Physiological response to stress
Perception, hormones and consequences
What are the parts of the adrenal glands?
Capsule, adrenal cortex and adrenal medulla
What is the capsule for?
A touch fibrous capsule enclosed in fat for protection
What is the adrenal medulla?
A knot of nervous tissue and is part of the sympathetic nervous system
What are the parts of the adrenal cortex?
Zona glomerulosa, Zona fasciculata, Zona reticularis
What does the zone glonerulosa produce?
Aldosterone
What does aldosterone do?
Regulates potassium and sodium secretion and retention
Plays a role in pH w/ ht excretion
Key in RAA pathway for BP and blood volume
What is aldosteronism?
Too much aldosterone leads to hypertension and edema due to increased sodium
What does decreased potassium do?
Cause weakness and sometimes paralysis
What does the zone fasiculata produce?
Cortisol
When is cortisol released?
With ACTH stimulation, there’s neg feedback with increased cortisol
What does cortisol do?
Increase blood glucose by decreasing peripheral uptake and promoting gluconeogenesis
Check if correct *
Why is diabetes hard to control in stressful situations?
Cortisol decreases insulin sensitivity
What does cortisol do in acute stage?
Promotes the breakdown of fatty acid Asa source of energy
What happens with sustained cortisol?
Body starts to redistribute fat (cushingoid signs)
How does cortisol effect immune system?
Supress t helper 1 cells (cellular immunity)
Promotes t helper 2 cells to increase humoral immunity and inc. Anti-inflammatory response
What is addisons disease?
Too little cortisol
What is cushings disease?
Too much cortisol, hyperglycemia, hypertension i edema, poor wound healing
What does the zone reticularis produce?
Gonadocorticoids, weak androgens, DHEA
What does DHEA do?
Can be conversed to testosterone or estrogen
Too much can lead to facial hair
What is the adrenal medulla made of?
Chromaffins or pheochromocytes
What are features of the adrenal medulla?
Rich nerve and blood supply
Epinephrine is secreted 10x more than norepinephrine
Responsive for SNS fight or flight
What is pheochromocytoma?
Tomor that secretes excess catecholamines
What does the zone glomerulosa produce?
Aldosterone
How does aldosterone play a role in ph?
H+ excretion
What is aldosteronism?
Too much aldosterone
What does aldosteronism do?
Causes hypertension and edema due to increased Na
What does the Zona fasciculata produce?
Cortisol
What does ACTH stimulation do?
Releases cortisol
What does cortisol do?
Increases blood glucose by decreasing peripheral uptake and promoting gluconeogenesis
What does the hypothalamus do when activated by stress?
Stimulates the locus ceruleus
What is synthesized in the locus ceruleus?
Norepinephrine
What is the pathway for norepinephrine?
From the locus ceruleus by afferent pathways back to the hypothalamus lambic system, hippocampal area and cerebral cortex
What happens when the SNS is activated?
Release of epinephrine and norepinephrine namely the chromatin cells
What does epinephrine do?
Increase glucose
Limit insulin
Causes bronchodilation
Promotes lipolysis
Increase heart rate
What does the anterior pituitary release?
ACTH, beta endorphins, prolactin and growth hormone
How does cortisol move through circulation?
Mostly bound to cortisol binding globulin and a small amount bound to albumin (prevents all of it from being cleared by the liver)
What do beta endorphins do?
Reduce pain
What does growth hormone do?
Affects protein, lipid and carb metabolism and counters the effects of insulin
What does the hypothalamus release?
Corticotropin releasing hormone
What does the posterior pituitary release?
ADH
What does ADH do?
Facilitates retention of Na and water and works in tandem with the ANS catecholamines and cortisol
How is acute stress beneficial?
It prepares the body for fight or flight
Where does acute stress occur?
Occurs at the level of the hypothalamus in the anterior pituitary
What does increased cortisol do to the hypothalamus?
Inhibits it from releasing more CRF and the anterior pituitary from releasing more ACTH
What happens to the negative feedback with chronic stress?
It becomes blunted or desensitized and no longer responsive to increased cortisol thus enabling the secretion of more CRF and ACTH
What is predominant in short term stress?
Catecholamine effects
What is predominant in prolonged stress?
Corticoids but calecholamines are still present
What is a positive consequence of stress?
Hypermedabolic state
What happens in a hypermetabolic state?
Lypolysis, gluconeogenesis and glycogenolysis which provides body with increased nutrient for healing and energy
What are negative consequences of stress?
Loss of muscle mass, nitrogen depletion, immune suppression’ hyperglycemia and cardiovascular wear and tear
Why would there be a loss of muscle mass?
Gluconeogenesis and protein catabolism
Why would there be nitrogen depletion?
Muscle catabolism and increased nitrogen excreted in urine
Why would there be immune suppression?
Decrease in t-cells and the thymi atrophy
Why would there be cardiovascular wear and tear?
Due to constant catecholamine release
What are two possible measurements of stress?
Biological and psychological/psychosocial
What are psychological measurement examples
Assess anxiety, fear, mood, coping and support
What are biological measurements of stress?
Testing for hyperglycemia, test adrenal function, cortisol levels etc
How are cortisol levels measured?
Looking at metabolites in 24h wine collections or serum/salivary levels
How do you access the adrenal cortex response?
Give ACTH
How do you measure negative seedbake of ACTH?
Give dexamethasome (synthetic glucocorticoid)
What is the hypoglycemic stress test?
Patient receives insulin to lower glucose to 2.2 then serum cortisol and growth hormone are measured
How does stress affect healing?
Decreased immune response, increased susceptibility to infections and slow wound healing
What all does increased cortisol affect?
Natural killer cells are depressed, these cells are first delense in detecting cancer cells
Which immune system is affected the most?
Adaptive immune system is depressed and less likely to irradiate pathogens, causing longer healing time
What part of the brain is very sensitive to glucocorticoids?
Hippocampus (important for verbal and contextual memory)
What happens when hippocampus is damaged with stress?
Neuronal atrophy, decreased short term memory, decreased accuracy of contextual memory i impaired ability to recognize threat
Symptoms of stress
Rising blood pressure, rapid heart rate, sweating hands, clenched teeth dropping sexual interest
Emotional symptoms of stress
Anxiety, depression, butterflies, irritability, overreactions, memory problems
What are clinical interventions for stress?
Eliminate stressor. Management of stress response and blocking the stress response
Non-pharmalogical treatments for stress
Relaxation, imagery, exercise, music and massage therapy
What does exercise do to cortisol?
Decreases cortisol secretion
