J

AdvancedPathophysiologyExam323pages

Advanced Pathophysiology Overview

  • Topics covered:

    • Nervous System

    • Inflammatory Process

    • Hypersensitivity Reaction

    • Infectious Process

    • Stress and Disease

    • Cancer Review

Nervous System Structure

  • Cerebral Cortex: Higher brain functions including thought and action.

  • Cerebrum: Largest part of the brain, responsible for sensory perception, initiation of movement, and cognitive functioning.

  • Pineal Gland: Regulates circadian rhythms by producing melatonin.

  • Lobes of the Brain:

    • Occipital Lobe: Visual processing.

    • Cerebellum: Coordinates voluntary movements, balance, and motor learning.

    • Parietal Lobe: Processes sensory information and spatial orientation.

    • Frontal Lobe: Involved in decision making, problem-solving, and control of behavior.

  • Thalamus: Relays sensory information.

  • Hypothalamus: Regulates homeostasis and links nervous system to the endocrine system via the pituitary gland.

  • Pons and Medulla: Control autonomic functions and relay signals to the cerebellum.

  • Spinal Cord: Transmits nerve signals between the brain and the body.

  • Corpus Callosum: Connects left and right hemispheres of the brain.

Autonomic Nervous System

  • Parasympathetic Nervous System: Conserves energy and supports rest and digestion.

  • Sympathetic Nervous System: Prepares the body for fight or flight response during stress.

    • Releases catecholamines (e.g., epinephrine).

    • Increases blood flow to muscles and lungs, decreases flow to gastrointestinal tract.

Brain Injury

  • Primary Brain Injury: Classifies as Focal or Diffuse

    • Focal Injuries: Specific lesions, e.g., epidural or subdural hemorrhage.

    • Diffuse Injuries: Include hypoxia and meningitis.

  • Intracranial Pressure: Swelling may increase ICP, causing potential dysfunction (e.g., Diabetes Insipidus).

Autonomic Hyperreflexia (Dysreflexia)

  • Affects individuals with spinal cord injury at T5-T6 or above.

  • Symptoms:

    • Severe hypertension (up to 300 mm Hg).

    • Intense headache, blurred vision, and sweating above injury level.

    • Bradycardia due to vagal stimulation.

Delirium vs. Dementia

Delirium:

  • Onset: Acute, often during hospitalization.

  • Duration: Hours to weeks.

  • Attention: Impaired.

  • Behavior: Agitated or withdrawn.

Dementia:

  • Onset: Insidious; can be acute in strokes.

  • Duration: Months to years.

  • Attention: Intact early, impaired late.

  • Behavior: Generally stable until late stages.

Alzheimer Disease & Stroke

  • Alzheimer Disease (AD): Leading cause of dementia, linked mainly to age and genetic factors.

  • Stroke Types:

    • Ischemic: Most common (thrombotic/embolic).

    • Global hypoperfusion and intracerebral hemorrhage.

  • Risk Factors for Stroke: Hypertension, diabetes, high cholesterol, heart disease, smoking, obesity, and inactivity.

Guillain-Barré Syndrome (GBS)

  • Autoimmune reaction triggered often by previous infections.

  • Symptoms: Plateauing or improving weakness usually occurs within four weeks.

  • Can cause respiratory weakness requiring ventilatory support in some cases.

Multiple Sclerosis (MS)

  • Chronic inflammatory disease targeting CNS myelin.

  • Symptoms and progression vary, with potential for rapid loss of motor function as the disease progresses.

Myasthenia Gravis (MG)

  • Autoimmune disease affecting neuromuscular transmission.

  • Symptoms include muscle fatigue that worsens with activity and improves with rest.

Parkinson’s Disease (PD)

  • Degeneration of dopaminergic neurons, primarily affecting motor control.

  • Symptoms include tremors, rigidity, and postural instability.

Pain Types: Acute vs. Chronic

Acute Pain:

  • Onset: Sudden.

  • Duration: Less than 6 months.

  • Clinical signs: Increased pulse, BP, and respiratory rates.

Chronic Pain:

  • Duration: Months to years; challenging to treat.

  • Often related to neuropathic pain, characterized by heightened sensitivity and abnormal processing of pain signals.

Sleep Deprivation

  • Disrupts sleep-wake cycles and can lead to serious health problems.

  • Obstructive Sleep Apnea Syndrome (OSAS): Causes reduced oxygen saturation and is common in both stressed individuals and those with comorbid conditions.

Hearing and Vision Disorders

Hearing Loss:

  • Conductive Hearing Loss: Due to blockage in the auditory pathway; better hearing in noise.

  • Sensorineural Hearing Loss: Damage to inner ear structures, often associated with aging (e.g., presbycusis).

Vision - Glaucoma:

  • Leading cause of blindness; involves increased intraocular pressure, which damages retinal ganglions.

Schizophrenia and Mood Disorders

Schizophrenia:

  • Associated with structural brain abnormalities; characterized by enlarged ventricles and altered brain structures.

Mood Disorders:

  • Major depressive disorder and bipolar disorder defined by symptoms including loss of interest, fatigue, and significant changes in behavior and cognition.

Inflammatory Process

  • Cardinal Signs of Inflammation:

    • Edema, warmth, redness, pain.

  • Phagocytosis: Involves recognizing, engulfing, and destroying pathogens.

Systemic Inflammation

  • Involves fever, leukocytosis, and altered plasma proteins, regulated by endogenous pyrogens affecting hypothalamus function.

Humoral and Cellular Immunity

  • Distinguishing factors between the roles of antibodies and T cells in the immune response, focusing on how each type targets different infectious agents.

Hypersensitivity Reactions

Types:

  1. Type I: IgE mediated (e.g., allergies).

  2. Type II: Targets specific cells/tissues; example includes ABO mismatched transfusion reactions.

  3. Type III: Immune complex-mediated (e.g., Raynaud phenomenon).

  4. Type IV: T lymphocyte-mediated (e.g., graft rejection).

Autoimmune and Alloimmune Diseases

  • Notable example: Systemic lupus erythematosus demonstrating a complex immune response leading to tissue damage.

Infectious Process

  • Involves the invasion of microorganisms, including direct confrontation with the immune system and potential outcomes like septicemia or toxin release leading to severe health consequences.

Acquired Immunodeficiency Syndrome (AIDS)

  • Caused by HIV, resulting in significant immune system dysfunction and increased susceptibility to infections and certain cancers.