Post on 14-Feb-2016
description
Respiratory tract pathology
Premed 2Pathophysiology
Common Upper respiratory tract Disorders
• Acute rhinitis-common cold-adenovirus
• Allergic rhinitis-type I hypersensitivity reaction-mast cells, basophils
• Bacterial infection-superimposed infection-common bacteria: Staphylococcus, Streptococcus, Hemophilus
• Sinusitis-inflammation of the paranasal sinuses
• Laryngitis-edema, inflammation, hoarseness
• Acute epiglotitis-severe, children-Hemophilus influenzae
• Acute laryngotracheobronchitis-croup-inflammation of the larynx, trachea and epiglottis-viral infection
Malignancies of the URT
• Nasopharyngeal carcinoma
-SEA and Africa-Epstein-Barr virus
• Squamous cell carcinoma-most frequently occurring tumor
Chronic Obstructive Pulmonary disease
• Airflow obstruction• Decrease in 1-minute forced expiratory
volume• Increased/normal forced vital capacity• Bronchial asthma• Chronic bronchitis• Pulmonary emphysema• Bronchiectasis
Bronchial asthma
• Episodes of dyspnea• Wheezing on expiration• Smooth muscle hypertrophy• Hyperplasia of the bronchial submucosal
glands and goblet cells• Viscid mucus with Curschmann spirals
and Charcot-Leyden crystals
Chronic bronchitis• Productive cough that occurs for 3 consecutive
months in 2 consecutive years• Hyperplasia of the bronchial submucosal
glandsincreased Reid index• Reid index: ratio of the thickness of the gland
layer to that of the bronchial wall• Cigarette smoking• Air pollution• Infection• Complication: cor pulmonale
Chronic bronchitis
Emphysema
• Dilatation of the air spaces• Destruction of the alveolar walls• Lack of elastic recoil• Increased antero-posterior diameter of the chest
• Hypoxia, cyanosis, respiratory acidosis• Cigarette smoking• Hereditary alpha-antitrypsin deficiency
Bronchiectasis
• Permanent abnormal bronchial dilatation• Chronic infection• Inflammation and necrosis of the bronchial
wall• Copious pururlent sputum• Hemoptysis• Lung abscess
• Predisposing factor:-bronchial tumor-Kartagener syndrome: sinusitis, bronchiectasis, situs inversus
Respiratory Distress Syndrome
• Surfactant– decreases the surface tension of
the alveoli– needed for alveoli to fill with air
and expand (compliance)• Infant respiratory distress syndrome
(hyaline membrane disease)• Adult respiratory distress syndrome
Neonatal respiratory distress syndrome
• Hyaline membrane disease• Most common cause of death in
premature infants• Dyspnea, cyanosis, tachynea after birth• Deficiency of surfactant: dipalmitoyl
lecithin; from type II pneumocytes
HMD
• Predisposing factorsprematuritymaternal diabetescaesarean section
Pneumoconiosis
• Anthracosis: carbon dust• Coal worker’s pneumoconiosis: coal dust• Silicosis: free silica dust• Asbestosis: asbestos fibers ferruginous
bodies-brochogenic carcinoma-malignant mesothelioma
Bronchogenic carcinoma
• Directly proportional to the number of cigarettes smoked daily and the number of years
• Air pollution• Radiation: radium, uranium• Asbestos• Nickel, chromates
Bronchogenic carcinoma
• 5-year survival rate: 10 %• Cough
hempotysisbronchial obstruction
• Local extension: pleura, pericardium, ribs
Bronchogenic carcinoma