NLE Foundations of Medical-Surgical Nursing — Homeostasis, Inflammation and Cellular ResponseConcept Map

Concept

Homeostasis and Stress Adaptation

Sub Concepts

• Homeostasis definition and set points
• Negative and positive feedback loops
• Stress and stressor types
• General Adaptation Syndrome (GAS) - three stages
• Local Adaptation Syndrome (LAS)
• Stress hormones: cortisol, aldosterone, ADH
• Sympathetic nervous system activation
• Hypothalamic-pituitary-adrenal (HPA) axis

Relationship To Central

Foundation of understanding how body maintains balance and responds to threats

Concept

Cellular Injury and Adaptation

Sub Concepts

• Cellular adaptations: atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia
• Cell death mechanisms: necrosis vs. apoptosis
• Causes of cellular injury
• Hypoxia as most common cause
• Ischemia and reperfusion injury
• Physical and chemical injury agents
• Infectious organisms causing injury
• Immune-mediated cellular injury

Relationship To Central

Describes how individual cells respond to stress before inflammatory response occurs

Concept

Inflammatory Response

Sub Concepts

• Inflammatory mediators: histamine, bradykinin, prostaglandins, leukotrienes
• Vascular events: vasodilation, increased capillary permeability
• Cellular events: migration, chemotaxis, phagocytosis
• Five cardinal signs of inflammation
• Systemic manifestations of inflammation
• Acute vs. chronic inflammation
• Wound healing phases
• Factors affecting wound healing

Relationship To Central

Protective nonspecific response to tissue injury and invasion

Concept

Fluid Shifts in Illness

Sub Concepts

• Third-spacing definition and causes
• Hydrostatic pressure
• Oncotic (colloid osmotic) pressure
• Plasma albumin role
• Intravascular volume depletion
• Edema formation mechanisms
• Fluid reabsorption phase
• Assessment and monitoring of fluid shifts

Relationship To Central

Explains abnormal fluid movement during stress and inflammation

Concept

Shock and Inadequate Perfusion

Sub Concepts

• Shock definition: inadequate tissue perfusion
• Classification: hypovolemic, cardiogenic, distributive, obstructive
• Stages of shock: initial, compensatory, progressive, refractory
• Anaerobic metabolism and lactic acidosis
• Manifestations by stage
• Priority interventions: ABCs
• Type-specific management
• Multiple organ dysfunction syndrome (MODS)

Relationship To Central

Critical endpoint when adaptive mechanisms fail to maintain tissue perfusion

To

General Adaptation Syndrome

From

Homeostasis

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strong

Relationship

Homeostasis disruption by stressor triggers GAS response

To

Stress Hormones

From

General Adaptation Syndrome

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strong

Relationship

GAS activates release of cortisol, aldosterone, and ADH

To

Inflammatory Response

From

Cellular Injury

Strength

strong

Relationship

Tissue injury directly triggers inflammatory cascade

To

Cardinal Signs of Inflammation

From

Inflammatory Mediators

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Chemical mediators produce the five cardinal signs

To

Inflammatory Response

From

Wound Healing

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strong

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Inflammatory phase is first phase of wound healing

To

Postoperative Complications

From

Stress Hormones

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Cortisol and fluid-retaining hormones cause hyperglycemia and edema post-op

To

Fluid Shifts in Illness

From

Inflammatory Response

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strong

Relationship

Inflammation increases capillary permeability, causing third-spacing

To

Oncotic Pressure

From

Hydrostatic Pressure

Strength

strong

Relationship

Both determine direction and amount of fluid shift

To

Hypovolemic Shock

From

Third-Spacing

Strength

strong

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Third-spacing can deplete intravascular volume and precipitate shock

To

Anaerobic Metabolism

From

Inadequate Tissue Perfusion

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Hypoxia forces cells to switch to anaerobic pathways

To

Metabolic Acidosis

From

Anaerobic Metabolism

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strong

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Anaerobic metabolism produces lactic acid causing acidosis

To

Priority Intervention Window

From

Compensatory Stage Shock

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Blood pressure still maintained; critical time to reverse shock

To

Type-Specific Management

From

Shock Classification

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Each shock type requires different fluid and medication approach

To

Atypical Presentation

From

Neurogenic Shock

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Causes bradycardia and warm skin unlike other shock types

To

Fluid Restriction

From

Cardiogenic Shock

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Limited fluids needed to prevent pulmonary edema

To

Dysplasia

From

Cellular Adaptations

Strength

moderate

Relationship

Dysplasia is premalignant progression beyond reversible adaptation

To

Nutrition Requirements

From

Factors Impairing Wound Healing

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strong

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Vitamin C, protein, and zinc are essential for proliferative phase

To

Cellular Injury

From

Hypoxia

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Hypoxia is the most common cause of cellular injury

To

Inflammation

From

Necrosis

Strength

strong

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Uncontrolled cell death triggers inflammatory response

To

Inflammation

From

Apoptosis

Strength

moderate

Relationship

Programmed cell death does not provoke inflammation

To

Early Shock Sign

From

Restlessness and Anxiety

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strong

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Earliest clinical sign of inadequate cerebral perfusion in shock

To

Shock Progression

From

Multiple Organ Dysfunction Syndrome

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MODS results from prolonged inadequate perfusion and oxygen delivery

To

Cortisol Secretion

From

HPA Axis

Strength

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HPA axis directly controls cortisol release during stress

To

Catecholamine Release

From

Sympathetic Nervous System

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Sympathetic activation triggers epinephrine and norepinephrine release

To

Edema Formation

From

Vasodilation and Capillary Permeability

Strength

strong

Relationship

Both increase fluid shift from intravascular to interstitial space