Pathophysiology Foundations, Cellular Function, and Immunity Flashcards
Pedagogical and Publication Overview
Book Identity: Pathophysiology: A Practical Approach, Edition, authored by Lachel Story, , , Professor and Dean at the College of Nursing and Health Professions, The University of Southern Mississippi.
Pedagogical Framework: The text uses an interactive strategy to drive comprehension and address diverse learning styles. It focuses on conceptual organization to provide a practical resource for learning.
Fifth Edition Updates: New and updated material appears in every chapter, including expanded life span considerations, emerging research (state-of-the-science insights), and new case studies for practical application.
Professional Utility: The text is intended both as a foundational learning tool for nursing students and a pragmatic reference for health professionals to refresh their memory on key concepts.
Introduction to Pathophysiology
Definition of Pathophysiology: The study of what happens when normal anatomy and physiology "go wrong." It acts as the functional foundation for nursing care, providing the "why" behind clinical mysteries, patient appearances, medical responses, side effects, and complications. It serves as the rationale for evidence-based medicine.
Health and Disease Concepts:
Health: Can be defined as the absence of disease or expanded to mean the wellness of mind, body, and spirit. It is relative to an individual's baseline and influenced by genetics, age, gender, and environment.
Disease: A state where a bodily function no longer occurs normally. It ranges from temporary stress to life-changing complications.
The Continuum: Health and disease are extremes on a single continuum, with optimal well-being at one end and life-threatening disease at the other.
Classifications of Disease:
Hereditary: Transmitted before birth.
Congenital: Present at birth.
Genetic: Caused by chromosomal abnormalities or mutations.
Developmental: Resulting from issues during embryonic or fetal development.
Inflammatory: Diseases that trigger the inflammatory response.
Degenerative: Conditions causing body parts to deteriorate (e.g., arthritis).
Metabolic: Conditions affecting metabolism (e.g., diabetes mellitus).
Neoplastic: Caused by abnormal/uncontrolled cellular growth (benign or malignant tumors).
Homeostasis and Biological Control
Core Concepts: Homeostasis is the state of equilibrium, balance, and stability. It is a self-regulating system that responds to stressors through compensatory mechanisms to return the body to a normal state.
Key Brain Structures in Homeostasis:
Medulla Oblongata: Located in the brainstem; controls blood pressure, temperature, and pulse.
Reticular Formation: A nerve cell network in the brainstem/spinal cord; relays vital function information to the hypothalamus.
Hypothalamus: Directs homeostasis by communicating with the pituitary gland.
Pituitary Gland: The "master gland"; regulates other glands related to growth, maturation, and reproduction.
Feedback Systems:
Negative Feedback System: The most common type; works to resist change and maintain a deficit in the system (e.g., temperature and glucose regulation).
Positive Feedback System: Moves the body away from homeostasis by amplifying a response in the same direction as the stressor (e.g., childbirth, sneezing, and blood clots).
Disease Development and Terminology
Etiology: The study of disease causation. Factors may be infectious, chemical, environmental, or unknown (idiopathic).
Iatrogenic: A disease or effect caused by an unintended result of a medical treatment.
Predisposing Factors: Tendencies putting individuals at risk (e.g., dietary imbalances or carcinogen exposure).
Pathogenesis: The sequence of events in how a disease develops.
Disease Onset and Duration:
Acute: Sudden onset with pronounced indicators (e.g., pain, vomiting) or short-term duration (e.g., tonsillitis).
Insidious/Chronic: Gradual onset with vague signals (e.g., hypertension) or long-term duration where the condition may not resolve (e.g., diabetes mellitus).
Clinical Manifestations:
Signs: Objective findings that can be measured or seen (e.g., heart murmur, lab levels).
Symptoms: Subjective complaints described by the patient (e.g., pain).
Syndrome: A group of signs and symptoms occurring together.
States of Disease Progression:
Remission: Manifestations subside.
Exacerbation: Manifestations increase.
Prognosis and Outcomes:
Convalescence: The stage of recovery.
Prognosis: Likelihood of full recovery.
Mortality: Death rate from a disease.
Complications: New problems arising because of a disease (e.g., renal failure from hypertension).
Epidemiology: The analysis of disease patterns in groups, including occurrence, incidence, prevalence, transmission, and distribution.
Morbidity: Disease rates within a group.
Epidemic: Increased disease numbers within a specific group.
Pandemic: An epidemic expanding to a larger population.
Cellular Function
Basic Cell Function: Cells arise only from preexisting cells. They undergo differentiation, a process where they become specialized for specific purposes.
Cell Components:
Cytoplasm (Protoplasm): Viscous liquid containing water, nutrients, ions, and gases.
Nucleus: Control center containing ; regulates growth, metabolism, and reproduction.
Cell Membrane (Plasma Membrane): Semi-permeable lipid bilayer. The interior is uncharged and lipophilic; the exterior is charged.
Organelle Highlights:
Mitochondria: Responsible for cellular respiration and energy production ().
Endoplasmic Reticulum (): Includes Smooth () for lipid/hormone synthesis and Rough () for protein synthesis.
Golgi Complex: Packages proteins.
Lysosomes: Contain digestive enzymes for waste and foreign materials.
Peroxisomes: Break down toxic molecules and fatty acids.
Cytoskeleton: Microtubules and microfilaments providing support.
Material Exchange Mechanisms:
Simple Diffusion: Movement of solutes from high to low concentration until equalized.
Osmosis: Passive movement of solvent across a membrane from low solute concentration to high solute concentration. Osmotic pressure is the solute's ability to attract water.
Facilitated Diffusion: Movement from high to low concentration with carrier molecules; no energy required.
Active Transport: Movement against a gradient using carrier molecules and energy (). Example: Sodium-potassium () pump.
Endocytosis: Engulfing substances (Phagocytosis for solids; Pinocytosis for liquids).
Exocytosis: Releasing materials via vesicles.
Cellular Energy Production
Sources: Breakdown of glucose (carbohydrates), triglycerides (fats), and proteins.
Aerobic Respiration:
Glycolysis: Occurs in the cytoplasm; converts glucose to pyruvate.
Krebs Cycle (Citric Acid Cycle): Occurs in the mitochondria; converts Acetyl into , water, and carbon dioxide.
Anaerobic Respiration: Occurs when oxygen is unavailable; pyruvate is converted to lactic acid. Excess lactic acid leads to muscle pain, metabolic acidosis, and organ failure.
Replication and Differentiation
Cell Proliferation: Regulated by genes (proto-oncogenes) and growth factors (cytokines).
Mitosis: Division resulting in two genetically identical diploid cells ( chromosomes). Phases: Prophase, Metaphase, Anaphase, Telophase.
Meiosis: Only in sperm and ova; results in haploid cells ( chromosomes).
Cell Aging: The Hayflick Limit suggests cells divide roughly to times before telomeres shorten to the point of programmed cell death.
Embryonic Development:
Totipotent/Pluripotent: Stem cells that can become any cell type.
Germ Layers: Ectoderm (epidermis, brain), Mesoderm (muscle, bone, circulatory), Endoderm (digestive tract, lungs).
Tissues of the Human Body
Epithelial Tissue: Tightly packed sheets for barriers, absorption, and secretion.
Types: Squamous, Cuboidal, Columnar (can be simple or stratified).
Connective Tissue: Cells in an extracellular matrix (collagen, fibers). Includes loose/dense tissue, adipose, bone, cartilage, and blood.
Muscle Tissue: Fibers containing contractile proteins (actin and myosin).
Skeletal: Striated, voluntary.
Cardiac: Striated, involuntary, connected by intercalated disks.
Smooth: Nonstriated, involuntary, found in hollow organs.
Nervous Tissue: Consists of neurons (transmit impulses via axons and dendrites) and neuroglia (support cells like astrocytes and Schwann cells).
Cellular Adaptation and Injury
Adaptive Changes:
Atrophy: Decrease in cell size/number due to disuse, ischemia, or low nutrition.
Hypertrophy: Increase in cell size to meet heavy work demands (normal in bodybuilding; abnormal in hypertension).
Hyperplasia: Increase in the number of cells (e.g., wound healing, menstruation).
Metaplasia: Replacement of one adult cell type with another cell type (e.g., ciliary changes in smokers).
Dysplasia: Mutation into atypical cells of different size/shape; precancerous.
Cell Death:
Apoptosis: Programmed, regulated cell death; cells shrink.
Necrosis: Cell death from injury; cells swell and burst.
Types of Necrosis:
Liquefaction: Caustic enzymes liquefy cells (brain).
Caseous: Granular, cottage-cheese appearance (tuberculosis).
Fat: Opaque, chalky appearance (acute pancreatitis).
Coagulative: Result of dropped and acidosis (kidney, heart).
Gangrene: Coagulative necrosis mixed with bacterial invasion.
Dry: Minimal bacteria; dark brown/black appearance.
Wet: Extensive damage from bacteria; liquid wound.
Gas: Caused by Clostridium; releases toxins and gas bubbles; potentially fatal.
Free Radicals: Unstable agents with unpaired electrons causing a domino effect of cellular damage; linked to cancer and aging. Protection provided by antioxidants (Vitamins , , beta-carotene).
Neoplasms and Cancer
Definition: Neoplasm (tumor) is a group of cells no longer responding to regulatory processes. Cancer is characterized by anaplasia (loss of differentiation).
Carcinogenesis Phases:
Initiation: Exposure to a carcinogen causing mutation.
Promotion: Mutated cells' exposure to growth factors; potentially reversible.
Progression: Permanent stage; tumor invades and metastasizes.
Tumor Characteristics:
Benign: Differentiated cells, slow growth, encapsulated, localized.
Malignant: Undifferentiated, rapid growth, invasive, able to metastasize.
TNM Staging System: Evaluates Tumor size, Nodal involvement, and Metastatic progress.
Grading System: Scale of to based on differentiation (Grade is well-differentiated; Grade is undifferentiated).
Tumor Markers: Substances secreted by cancer cells (e.g., for prostate, for liver, for ovarian cancer).
Stress and the General Adaptation Syndrome (GAS)
The Stress Response: Described by Hans Selye as a cluster of systemic manifestations to cope with a stressor.
Stages of GAS:
Alarm: Stimulation of the sympathetic nervous system; release of catecholamines and cortisol ("fight-or-flight").
Resistance: Body chooses effective defenses; cortisol levels normalize; attempt to limit damage.
Exhaustion: Prolonged stress depletes resources; damage occurs as homeostasis fails; can lead to death.
Local Adaptation Syndrome (LAS): Confining a stressor to one location (e.g., local inflammatory reaction).
Immunity Defenses
Innate Immunity (Nonspecific): Immediate protection.
Barriers: Skin, mucous membranes, hydrochloric acid, lysozyme in tears.
Microbiome: Healthy microorganisms outnumber human cells to .
Inflammatory Response: Triggered by mast cells releasing histamine (vasodilation) and prostaglandins (pain/permeability).
Pyrogens: Trigger hypothalamus to cause fever; limits bacterial iron availability.
Interferons: Released by virus-infected cells to protect uninfected neighbors.
Complement System: Group of proteins; forms membrane-attack complexes to burst bacteria; promotes opsonization (marking for phagocytosis).
Adaptive Immunity (Specific): Takes to days for initial response.
Cellular Immunity: Mediated by cells ( Helper; Cytotoxic Killer).
Humoral Immunity: Mediated by cells; mature in bone marrow into plasma cells (secrete antibodies) or memory cells.
Immunoglobulins:
IgG: Main defense; crosses placenta.
IgM: First antibody made by fetus; fights blood infections.
IgA: Found in respiratory/GI tracts, tears, saliva, colostrum.
IgE: Triggers allergic reactions; responds to parasites.
IgD: Receptor for antigens on cells.
Altered Immune Responses
Hypersensitivity Types:
Type I (IgE-Mediated): Allergic reactions, anaphylaxis; involves mast cell degranulation.
Type II (Tissue-Specific): Cytotoxic; or destroys target cells (e.g., blood transfusion reaction, erythroblastosis fetalis).
Type III (Immune-Complex Mediated): Accumulation of antigen-antibody complexes in tissues (e.g., , rheumatoid arthritis).
Type IV (Cell-Mediated): Delayed-type; controlled by cells; no antibodies involved (e.g., tuberculin skin test, contact dermatitis).
Practical Clinical Applications and Case Studies
Case Study: Mrs. Coleman ( Female):
Findings: firm, fixed, tender mass in right breast; palpable axillary node. History: Mother died of breast cancer; early menarche (age ); birth control use.
Diagnosis: Type tumor, Stage breast cancer; estrogen-dependent.
Risk Factors Identified: Family history, early menarche, age, ethnicity.
Case Study: Adolescent Male ( ):
Findings: Shortness of breath, systolic murmur, high percentile for height (), low percentile for weight ().
Likely Diagnosis: Marfan Syndrome.
Rationalization: Skeletal characteristics (tall/thin) combined with cardiac findings (murmur indicating valvular defect/aortic issues) are hallmarks of the mutation.
PKU Case Detail: Treated with a diet low in phenylalanine; avoiding proteins and aspartame is critical to preventing severe intellectual disability.
Tay-Sachs Detail: Rare mutation in gene; affects lipid metabolism in nerve cells; common in populations of Jewish descent; fatal usually by age .