Exam 1

Question 1

General Adaptation Syndrome (GAS)

Answer 1

1. Alarm stage - stressor triggers hypothalamus/pituitary/adrenal HPA) axis. The sympathetic nervous system is activated; body’s defenses are aroused.
2. Resistance/Adaptation stage - adrenal hormones are released. This can contribute to fight or flight response
3. Exhaustion stage - occurs when stress continues and adaptation fails; leads to stress-related disorders.

Question 2

Who developed the GAS syndrome model

Answer 2

Hans Selye in the 1930s; defines stress as challenging demand on body arouses response in multiple organs

Question 3

Alarm stage

Answer 3

• Stressor; dz, or threat triggers HPA axis and sympathetic nervous system is stimulated and epinephrine/norepinephrine is released –> fight or flight stimulated.
• Catecholamines cause increased BP, HR, and RR
• Liver releases glycogen –> increased blood glucose levels
  
  • Pts on PO antidiabetics may need SQ insulin because increased level of glucose compared to when they are not hospitalized
• Cortisol –> increased levels will cause increase in WBCs to counteract any present inflammation.

Question 4

Resistance/Adaptation stage

Answer 4

• Adrenal hormones still released
  
  • can contribute to sympathetic response
• sympathetic and parasympathetic system work to maintain balance and allow an individual to overcome stressors and avoid exhaustion stage
• high levels of hormone and catecholamines cannot be maintained with an increase in stress or prolonged stress; systematic dysfunction sets in.
  
  • chronic illness can effect balance

Question 5

Gluccorticoid response

Answer 5

• Stress messages sent to brain and stimulates hypothalamus
• Hypothalamus (controls temp) enables release of glucocorticoids
• glucocorticoids trigger release of adrenaline and cortisol
• adrenaline causes a boost in energy; HR increase, BP increase, blood glucose increase (sympathetic stimulation) Governed by ANS –> this helps individual to fight back or run.

Question 6

Cortisol

Answer 6

• Secreted during stress –> mobilizes glucose, fat and amino acids to increase muscle strehgth
• potentiates sympathetic response
• Stimulates WBC released in bone marrow
  
  • initially immunity is enhanced
  • after 3-5 days may cause immunosuppression
    
    • explains why chronically ill patients are susceptible to illness
• reaches all tissues
• stimulates gluconeogenesis
  
  • elevated blood glucose
• Affects protein metabolism
• anti-inflammatory
• immunosuppressive
• Allostasis; Allostatic overload –> wear and tear by constant stress reaction –> maladaptive response –> pathophysiologic condition
  
  • HTN –> endothelial damage –> atherosclerosis

Question 7

Immune system role in stress

Answer 7

• stress directly related to proinflammatory cytokines –> cellular phase of inflammation –> chemotaxis –> WBC will counter act stress response (cytokine response). Involved in many dz processes
• Link btwn stress, immune fxn, with various dz including CA
• Immune system affected by neuroendocrine factors
• Stress response decreases T cell cytotoxicity and B cell fxn

Question 8

Aging and Stress

Answer 8

• Stress Age syndrome
  
  • body loses ability to adapt over time
• Excitability changes the limbic system and hypothalamus
• Increased catecholamines, ADH, ACTH, and cortisol
• Alterations of opioid peptides
• Immunosuppression and pattern of chronic inflammation
• Alterations in lipoproteins
• Hypercoagulation of blood
• Free radical damage to cells