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• Behavior: Agitated or withdrawn.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.