Pathophysiology Introduction and Framework

Pathophysiology Introduction

• The study of the functional changes in cells, tissues, and organs of the body that cause or are caused by disease.
• Combines principles of pathology (study of disease) with physiology (study of the body's functions).
• Examines physical changes caused by disease and their impact on the overall functioning of the body.
• Example: Understanding how inflammation from an infection can cause fever by altering how the hypothalamus regulates temperature.

Components of Pathophysiology Framework

• Etiology: The cause of a disease, including biological agents, chemical agents, physical forces, genetics, and nutritional excesses or deficits. Risk factors increase susceptibility. Most diseases have multiple factors.
• Pathogenesis: The development of the disease, including the sequence of cellular and tissue events from initial exposure to disease manifestation. Focuses on the process of disease development rather than the cause. Includes the body's compensatory responses.
• Clinical Manifestations: The signs and symptoms of the disease; signs are objective and observed by clinicians, while symptoms are subjective complaints from the patient. Includes the body's compensatory responses to disease.
• Diagnostics: The determination of a disease through patient history, physical examination, and diagnostic tests. Dependent on both etiology and clinical manifestations.
• Therapeutics: Treatment aimed at reducing or eliminating the cause and/or clinical manifestations of a disease.

Role of Pathophysiology in Nursing Care

• Provides a basis for nurses to make informed decisions about patient care.
• Identifies the specific needs of patients and performs accurate assessments to recognize signs and symptoms of disease.
• Enables nurses to develop and implement appropriate interventions based on professional assessments and understanding of disease processes.
• Helps nurses evaluate the effectiveness of treatments.
• Assists nurses in explaining to patients how diseases affect the body and the purpose of specific treatments.
• Provides knowledge about pathogens, their structural differences, and terms for infection and damage to inform decisions on treatment and prevention.

Key Terms in Pathophysiology

• Etiology: The cause of a disease (biological agents, physical forces, chemical agents, genetics, or nutritional imbalances).
• Pathogenesis: The development or evolution of a disease (sequence of cellular and tissue events).
• Manifestations: The signs and symptoms of a disease (subjective and objective).
• Diagnostics: Processes of determining the cause of a health problem (history, physical exam, tests).
• Therapeutics: Treatments aimed at addressing the cause or manifestations of a disease.
• Clinical Course: The evolution of a disease over time (acute, chronic, subacute, or acute on chronic).

Mechanisms of Disease

• Genetic Mechanisms: Disorders caused by mutations, chromosomal abnormalities, or mitochondrial defects (e.g., cystic fibrosis, sickle cell disease).
• Environmental Agents: Factors from the environment; (e.g., physical, chemical, biological agents).
• Immunological Mechanisms: Disorders involving the immune system, e.g., autoimmunity, and hypersensitivity.
• Cellular Injury and Death: Damage to cells caused by various agents, leading to necrosis or apoptosis (e.g. hypoxia, free radicals, toxins).
• Neoplasia: Abnormal and uncontrolled tissue growth, leading to benign or malignant tumors.
• Degeneration: Decline in cellular and tissue function due to aging or disease.
• Nutritional Imbalances: Diseases caused by nutrient deficiencies or excesses.
• Inflammation: Protective response to tissue injury or infection; chronic inflammation can lead to disease.
• Pathogenesis: Sequence of events from exposure to an etiologic agent to disease manifestation.

Factors Contributing to Disease Development

• Age: Susceptibility increases at the extremes of age.
• Gender: Hormonal and genetic differences influence susceptibility.
• Genetics: Inherited mutations and chromosomal abnormalities.
• Lifestyle: Choices like smoking, alcohol consumption, poor diet, and lack of exercise.
• Nutrition: Nutritional imbalances affect immune response and disease susceptibility.
• Sleep-Wake Cycles: Sleep disorders negatively impact immune function.
• Psychosocial Factors: Chronic stress, poor mental health, and lack of social support.
• Physical Environment: Exposure to hazards like pollution, radiation, or extreme temperatures.
• Infectious Agents: Pathogens causing infections.
• Chemical Agents: Toxins, poisons, and harmful chemicals.

COVID-19 (SARS-CoV-2) Pathophysiology

• Causative agent: SARS-CoV-2 virus.
• Entry: Inhalation/contact with contaminated surfaces.
• Binds to ACE2 receptors.
• Virus replicates in respiratory cells.
• Results in inflammatory responses.
• Severity depends on viral replication, immune response, and underlying conditions.

Chain of Infection

• Infectious Agent: Pathogen causing the disease (e.g., bacteria, viruses, fungi, parasites).
• Reservoir: Place where the infectious agent lives and multiplies (e.g., human, animals, environment).
• Portal of Exit: Pathway for the infectious agent to leave the reservoir (e.g., respiratory secretions, blood, feces).
• Mode of Transmission: How the infectious agent moves between the reservoir and the host (e.g., direct or indirect contact, airborne droplets, vehicles).
• Portal of Entry: Pathway for the infectious agent to enter the susceptible host.
• Susceptible Host: Individual vulnerable to infection due to factors like age, immunity, or health status.

Local vs Systemic Infections

• Local Infections: Confined to a small area of the body.
• Systemic Infections: Spread throughout the body, often via the bloodstream.

Stages of Infection

• Incubation Period: Pathogen replication without symptoms.
• Prodromal Stage: Initial vague symptoms.
• Acute Stage: Pronounced and specific symptoms.
• Convalescent Period: Symptoms subside; pathogen elimination begins.
• Resolution Stage: Pathogen completely eliminated.

Explore the foundations of pathophysiology, focusing on the functional changes in the body caused by diseases. This quiz covers key components such as etiology, pathogenesis, and their implications for health. Gain a deeper understanding of how diseases develop and affect bodily functions.