Last saved 23 days ago

Stress and Inflammatory Responses

robot
knowt logo

Stress and Inflammatory Responses

Stress and Inflammatory Responses

  • Course Information: NUR 112, Spring 2025

Resources

  • Textbook: Hinkle and Cheever, Chapter 5

Learning Objectives

  • Describe the significance of:

    • Internal constancy

    • Homeostasis

    • Stress and adaptation in maintaining the body's steady state.

  • Understand the general adaptation syndrome (GAS) and its relevance to stress responses:

    • Sympathetic-adrenal-medullary

    • Hypothalamic-pituitary responses

  • Identify maladaptive stress responses that increase illness risk and disease.

  • Compare adaptive processes:

    • Atrophy

    • Hypertrophy

    • Hyperplasia

    • Metaplasia

    • Dysplasia

  • Assess health patterns in individuals/families and strategies for stress reduction.

Steady State

Four Concepts

  • Constancy

  • Homeostasis

  • Stress

  • Adaptation

Constancy and Homeostasis

  • Homeostasis: Steady state within the body.

    • Changes trigger responses to maintain homeostasis.

    • Involves compensatory mechanisms for balance.

Stress and Adaptation

  • Stress: State caused by environmental changes threatening equilibrium.

  • Adaptation: Adjusting to change to restore equilibrium.

  • Coping: Physiological and psychological compensatory processes.

Stressors

  • Upset equilibrium.

  • Defined as internal or external events/situations that lead to:

    • Physiological, emotional, cognitive, or behavioral changes.

Types of Stressors

  • Physical Stressors: Cold, heat, chemical agents.

  • Physiological Stressors: Pain, fatigue.

  • Psychosocial Stressors: Fear.

Selye’s General Adaptation Syndrome (GAS)

  • Three Phases:

    • Alarm Phase: Defensive and anti-inflammatory response.

    • Resistance Phase: Adaptation to noxious stressors.

    • Exhaustion Phase: Occurs with prolonged stressors.

Local Adaptation Syndrome

  • Inflammatory response and repair process.

Brain Mechanisms of Stress Response

  • Hypothalamus: Central for stress response.

  • Cerebral Hemispheres: Cognitive functions.

  • Limbic System: Emotional responses and initial sympathetic response.

Sympathetic Nervous System Response

  • Rapid, short-lived reaction:

    • Norepinephrine release

    • Peripheral vasoconstriction → ↑ Blood pressure, ↑ Heart rate

    • Increased respiration rate

    • Increased blood glucose

    • Dilated pupils

    • Heightened mental awareness.

Effects of Sympathetic-Adrenal-Medullary Reaction to Stress

  • Purpose and Mechanism:

    • Increased cardiac output

    • Increased energy availability

    • More perfusion to vital organs

    • Higher mental acuity and alertness

    • Increased blood flow to brain and muscles

    • Increased ventilation and muscle tension

    • Prevention of hemorrhage.

Hypothalamic-Pituitary Response

  • Long-lasting response during persistent stress.

    • Cortisol metabolic effects provide energy.

    • Implications for diabetics requiring more insulin.

  • Hormonal interactions:

    • Hypothalamus → Anterior Pituitary → ACTH → Adrenal Cortex (Cortisol) → ADH, Gluconeogenesis, Aldosterone.

Physiological Response to Stress

  • Maladaptive Responses:

    • Chronic stress responses impede adaptation.

    • Faulty appraisals and inappropriate coping can lead to diseases like hypertension, cancer, etc.

Negative Feedback Mechanism

  • Monitors internal environment, restores homeostasis by sensing deviations and triggering responses.

  • Major organs involved: Heart, lungs, kidneys, liver, GI tract, skin.

Cellular Adaptation

  • Types:

    • Atrophy: Reduction in size due to disease, inactivity, etc.

    • Hypertrophy: Increase in muscle mass, typically in cardiac and skeletal muscles.

    • Hyperplasia: Increase in new cell numbers, often hormonally induced.

    • Metaplasia: Replacement of one cell type by another.

    • Dysplasia: Abnormal growth that signals potential malignancy.

Causes of Cellular Injury

  • Various causes lead to loss of steady state:

    • Hypoxia: Insufficient oxygen supply (ischemia).

    • Nutritional Imbalance: Deficiency or excess of nutrients.

    • Physical Agents: Burns, mechanical trauma, radiation.

    • Chemical Agents: Toxins like mercury, arsenic.

    • Infectious Agents: Bacteria, viruses, fungi.

    • Genetic Disorders and Immune Mechanisms.

Inflammatory Process

  • Local reaction to neutralize harmful agents:

    • Sequence: Vasodilation, increased permeability, leukocyte infiltration.

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

Phases of Inflammation

  • Acute: Lasts < 2 weeks, immediate protective response.

  • Chronic: Lasts for months/years, debilitating effects.

Reparative Process

  • Begins simultaneously with injury:

    • Healing by regeneration or replacement:

      • Regeneration: Same type of cells replace damaged ones.

      • Replacement: Different cells fill defect (scar tissue).

Nursing Management

  • Early identification and assessment of stressors.

    • Vital signs evaluation, emotional distress assessment, cognitive function checks, and diagnostic studies.

Nursing Interventions

  • Promoting healthy lifestyles.

  • Enhancing coping strategies and education on stress management.

  • Fostering family health and social support.

  • Recommending therapy/support groups.