ASTHMAASTHMA

By:By:

Mohammed A. AlquwaizaniMohammed A. Alquwaizani

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Asthma :Asthma : Current Understanding of the Disease, and a Summary Current Understanding of the Disease, and a Summary

of the Harlem Children’s Zone Asthma Initiativeof the Harlem Children’s Zone Asthma Initiative

Descriptions of AsthmaDescriptions of Asthma

• Asthma: Asthma: ancient Greek for “panting”ancient Greek for “panting”

• Definition: a narrowing of the airways in the Definition: a narrowing of the airways in the lungs that causes coughing, wheezing, and lungs that causes coughing, wheezing, and gasping for breath.gasping for breath.

• Pathology: airflow obstruction, airway hyper-Pathology: airflow obstruction, airway hyper-responsiveness, and airway inflammation.responsiveness, and airway inflammation.

The Respiratory SystemThe Respiratory System

Airways:Airways:Trachea and Bronchial TubesTrachea and Bronchial Tubes

Gas Exchange Region:Gas Exchange Region:Bronchioles and AlveoliBronchioles and Alveoli

Airway Inflammation and Smooth Muscle Airway Inflammation and Smooth Muscle ReactivityReactivity

Asthma Triggers:• Viral/Bacterial infections• Chemical irritants: industrial, household•Air pollution: CO, ozone•Tobacco smoke•Dust mite/cockroach allergens•Animal dander, urine •Exercise, cold air, emotion, stress

Inflammation

Airway Hyper-responsiveness Airflow Obstruction

Asthma Symptoms

Model of an Inflammatory Response Leading to AsthmaModel of an Inflammatory Response Leading to Asthma

Phase 1. Sensitization of immune systemPhase 1. Sensitization of immune system

Repeated exposures to an allergenRepeated exposures to an allergen

Production of allergic antiboidies (IgE’s) by immune systemProduction of allergic antiboidies (IgE’s) by immune system

Phase 2. Immediate hypersensitivity to subsequent exposuresPhase 2. Immediate hypersensitivity to subsequent exposures

IgE’s recognize and bind to allergensIgE’s recognize and bind to allergens

Immune cells to release inflammatory chemicals (Histamine, etc.)Immune cells to release inflammatory chemicals (Histamine, etc.)

Inflammatory chemicals cause:Inflammatory chemicals cause:• Constriction of airway smooth muscleConstriction of airway smooth muscle

• Secretion of mucous from glands in airway wallSecretion of mucous from glands in airway wall• Fluid leakage (edema) in airway wallsFluid leakage (edema) in airway walls

Pathology of AsthmaPathology of Asthma

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Pathology of AsthmaPathology of Asthma

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