L15: Stress & Illness

Question 1

Function of cortisol response/release.

Answer 1

• Keeping stress response under control

Question 2

What are the two types of stress?

Answer 2

• Physiological/biologic stress - Psychological stress *These can be acute, episodic or chronic

Question 3

What is a hallmark of stress?

Answer 3

• Cortisol release

Question 4

Describe regions on stress curve in terms of performance and health

Answer 4

• Low stress: low performance, low health – unadapted (diseases of underuse) - Optimum stress: high performance, high health rating - High stress: low performance, low health-breakdown (diseases of overuse)

Question 5

Manifestations of stress

Answer 5

• Trouble focusing - tachycardia - increased BP - sweating - GI - Muscle tenseness, tremors - Appetite changes - Sleep disturbances - Difficulty thinking - Anxiety, fear, helplessness

Question 6

Explain and stress and responses to stress have a genetic component.

Answer 6

• Genetics can allow you be more resilient or more vulnerable (accompanied with co-morbidities) to stress - Early life exposures to stress will have long-last effects on ability to deal with stress - Example: nurtured pups = much more equipped to deal with stress than neglected

Question 7

Which portion of brain is underdeveloped as a result of PTSD?

Answer 7

• Hippocampus

Question 8

Define allostasis.

Answer 8

• Activity that is required for individual to maintain stability through change, ie. adaptation/adaptive reactions. Think of as active means of maintaining homeostasis

Question 9

Define homeostasis.

Answer 9

• Collective processes that maintain and internal equilibrium. This can achieve behaviors and emotions acting in concert with autonomic and endocrine regulation

Question 10

Compensatory responses

Answer 10

• Stress response that deviates from a poorly defined normal range of physiological responses with the function of protecting living things against severe stressors/threats.

Question 11

Are stress effects reversible? Explain

Answer 11

• Yes. Hippocampus has plasticity. Increased survival and growth of neurons and increased neurogenesis is seen with antidepressants.

Question 11

Most reported indicators of stress seen in medical students?

Answer 11

• Gained weight, anxiety, sleep problems

Question 13

Role of ANS in stress response.

Answer 13

• Main internal regulatory mechanisms designed for maintenance of homeostasis - Two divisions: SNS and PSNS; flight/fight vs rest/restoration respectively

Question 14

Describe the mechanism used to provoke responses to psychological stressors?

Answer 14

• Provoke responses using “top-down” mechanisms. - These responses originate as thoughts or learned reactions and behaviors in higher cognitive centers in brain. They affect hypothalamic and brainstem mechanism involved in control of same regulatory systems that maintain homeostasis in response to physical threats.

Question 14

What illnesses/diseases does chronic stress increase your risk for?

Answer 14

• CV disease (sudden death, atherosclerosis, myocardial hypertrophy and HTN) - GI disorders (diarrhea, peptic ulcers, IBS aggravation) - Immune system dysfunction (HPA activation suppresses immune and inflammatory response, promotes inhibition of innate immunity) - Chronic pain

Question 15

Which portion of the brain is underdeveloped as a result of repeated doses of glucocorticoids (ie. cortisol)?

Answer 15

• Hippocampus

Question 16

What is allostatic load?

Answer 16

• Cost to body and brain of maintaining homeostasis – physiological wear and tear

Question 18

What are the contributing factors from stress that lead to increased risk of disease?

Answer 18

• Increased HR and BP - Stress hormones on immune processes. Eg. Corticosteroid suppresses immune system - Disturbance of GI

Question 19

Factors and measures employed to mitigate stress/response to stress as medical student.

Answer 19

• Mitigation factors: positive health, self-esteem, socioeconomic status - Management: sleep, social, outlook, pharmacologic, physical acitivity

Question 20

Describe components and role of CNS and endocrine components in stress response

Answer 20

• Amygdala: fear processing, regulation of emotional reactions (facial expression studies). Activated through innate and learned response to threat. Lateral amygdala/PFC = anxiety (distant danger). Central amygdala and periaqueductal gray = panic (near danger) - Prefrontal cortex: perception and appraisal of threat underlying psychological stress response - Hypothalamus: autonomic responses, endocrine function, maintenance of homeostasis - Hippocampus: learning and formation of new memory, sensory processing and interpretation, homeostasis (connection with hypothalamus), atrophy / decreased neurogenesis of this area with chronic stress - HPA axis

Question 21

Describe the mechanism used to provoke responses to physiologic/biologic stressors?

Answer 21

• These provoke responses using “bottom-up” mechanisms: spinal cord to brainstem to hypothalamus / limbic system to evoke homeostatic response. Hypothalamus regulates autonomic, endocrine and motor function output at level of brainstem. Higher brain centers are responsible for behavioral and emotional aspects of stress response dependent on visual, auditory, olfactory and motor system activation.

Question 22

Correlation bw men / women and stress.

Answer 22

• Men: higher stress related to respiratory diseases, suicide, heart disease. More pronounced for younger healthier men - Women: no association found bw stress and mortality among women (except younger women with high stress who experienced lower cancer mortality)

Question 23

Define stress.

Answer 23

• presence of significant physiological or psychological threat resulting in acute/persistent strain on body’s compensatory systems

Question 24

Which divisions of the amygdala have highest levels of activation depending on the proximity/closeness of danger?

Answer 24

• Central amygdala = close (central – close) - Lateral amygdala = long/far (long – lateral)

Question 25

What are Seyle’s General Adaptation Syndrome Phases. Describe each.

Answer 25

• Profile of how organisms respond to stress - Phase 1: alarm stage a.) Shock phase: body endures stressor effect and resistance to stressor drops temporarily b.) Antishock phase: body starts to response and is in state of alarm-SNS activated (adrenalin, cortisol, etc. released) - Phase 2: resistance stage Increase in systemic glucocorticoid levels = increased glucose, fat and protein conc in blood. Need for adaptation to persistent stressor as body’s resources are being depleted. - Phase 3: exhaustion stage Loss of normal function. If this stage is extended, long-term damages of stress results = ulcers, DM, angina, depression etc.). Recovery and restoration of homeostasis follows when compensatory mechanisms overcome stressor effect