Chapter05 stress 2

Chapter 5: Stress and Inflammatory Responses

Constancy and Homeostasis

• Claude Bernard’s Principle: "fixity of the internal milieu"

• Homeostasis: A dynamic steady state within the body.

• Response to Change: When change occurs, the body initiates compensatory mechanisms to maintain homeostasis.

Stress and Adaptation

• Stress: A state produced by environmental changes perceived as threats to equilibrium.

• Adaptation: The adjustment process that restores equilibrium.

• Coping: A dual process involving physiological and psychological components.

Stressors

• Definition: Internal or external events that disrupt equilibrium, leading to physiological, emotional, cognitive, or behavioral changes.

Types of Stressors

• Physical Stressors: Examples include extreme temperatures, and chemical agents.

• Physiologic Stressors: Include pain and fatigue.

• Psychosocial Stressors: Examples are fear and anxiety.

Selye’s General Adaptation Syndrome (GAS)

• Theory: Describes the body’s adaptation to biological stress.

• Phases:

  • Alarm Phase: Initiated by the sympathetic nervous system, leading to a fight-or-flight response.

  • Resistance Phase: The body adapts to the stressor, with cortisol levels remaining elevated.

  • Exhaustion Phase: Persistent stress leads to potential bodily failure.

Brain and Stress Response

• Brain Areas Involved:

  • Hypothalamus: Triggering sympathetic response.

  • Cerebral Hemispheres: Responsible for cognitive function.

  • Limbic System: Involved in emotional responses.

• Initial Response: Activation of the sympathetic nervous system followed by the hypothalamic-pituitary axis.

Physiologic Response to Stress

• Sympathetic–Adrenal–Medullary Response:

  • Triggered by the fight-or-flight response, releasing epinephrine and norepinephrine, which increase metabolic effects and glucose levels.

Hypothalamic–Pituitary Response

• Function: Prolonged phase of hormonal response during continuous stress, with cortisol providing energy.

• Considerations: Individuals with conditions like diabetes may require increased insulin due to elevated cortisol-induced glucose levels.

Maladaptive Response to Stress

• Definition: Chronic responses to stress that fail to support adaptation, leading to health issues.

• Examples of Disorders: Hypertension, cardiovascular disease, and various mental/physical health conditions related to prolonged stress.

Negative Feedback Mechanisms

• Function: Continuous monitoring and adjustment to maintain internal homeostasis, affecting critical physiological parameters (e.g., blood pressure, blood glucose).

• Major Organs: Heart, lungs, kidneys, liver, and gastrointestinal tract are involved in these feedback mechanisms.

Cellular Adaptation and Injury

• Cellular Responses: Includes changes like hypertrophy, atrophy, hyperplasia, and dysplasia, indicating how cells adjust or change due to stress or injury.

• Causes of Cellular Injury: Includes hypoxia, nutritional imbalances, infectious agents, and physical trauma.

Inflammatory Process

• Definition: Localized response to neutralize harmful agents, marked by vasodilation and increased vascular permeability.

• Cardinal Signs: Redness, warmth, swelling, pain, and loss of function denote inflammation.

Reparative Process

• Two Pathways:

  • Regeneration: Repair by proliferation of the same cell types.

  • Replacement: Involves scar formation from different cell types.

Nursing Management and Interventions

• Focus Areas:

  • Early identification and assessment of stressors (vital signs, emotional state, etc.).

  • Interventions include promoting healthy lifestyles, enhancing coping strategies, and teaching relaxation techniques.

Guided Imagery

• Teaching Element: Uses words, phrases, or images to distract from distressing situations; not to be confused with progressive muscle relaxation.