Respiratory Pathology Flashcards
What are the main components of the respiratory system?
larynx Nasal passages
Define acinus in the respiratory system.
An acinus is composed of respiratory bronchioles alveolar ducts
What are the walls of alveoli responsible for?
Gas exchange within the lungs.
What is pulmonary hypoplasia?
Underdeveloped lungs with decreased weight and acini often due to issues that impede lung expansion.
What are foregut cysts?
Abnormal detachment from the foregut classified as bronchogenic
Define pulmonary sequestration.
An area of lung tissue that lacks connection to the airway and has an abnormal blood supply.
What is Hyaline Membrane Disease (HMD)?
A condition in premature infants caused by a lack of surfactant leading to respiratory distress.
What is bronchopulmonary dysplasia?
A chronic lung disease in infants typically following HMD
Define pneumonia.
An infection of the lung parenchyma caused by impaired lung defenses or reduced host immunity.
What are the two main types of pneumonia based on anatomic distribution?
Bronchopneumonia (patchy lung consolidation) and lobar pneumonia (consolidation of a lobe).
What is community-acquired pneumonia?
Pneumonia acquired from the general environment often in healthy individuals
List common causes of community-acquired bacterial pneumonia.
Streptococcus pneumoniae Haemophilus influenzae
What characterizes lobar pneumonia?
Consolidation of a large portion of or an entire lung lobe.
Describe the four stages of lobar pneumonia.
Congestion red hepatization
What are the risk factors for healthcare-associated pneumonia?
Hospitalization nursing home residency
What is aspiration pneumonia?
Pneumonia from inhaling gastric contents often seen in debilitated patients.
Define chronic pneumonia.
A persistent lung infection often caused by organisms like Mycobacterium tuberculosis and Histoplasma capsulatum.
What is chronic obstructive pulmonary disease (COPD)?
A group of lung diseases characterized by increased airway resistance including emphysema and chronic bronchitis.
Describe emphysema.
A chronic respiratory condition with irreversible enlargement of airspaces and destruction of alveolar walls.
What are the primary types of emphysema?
Cenriacinar (centrilobular)
Panlobular
Distal acinar (paraseptal)
Irregular
What enzyme imbalance contributes to emphysema?
Protease-antiprotease imbalance specifically due to α1-antitrypsin deficiency.
List symptoms of emphysema.
Dyspnea barrel chest
Define chronic bronchitis.
A chronic cough with sputum production for at least 3 months in 2 consecutive years.
What causes chronic bronchitis?
Exposure to irritants like tobacco smoke leading to mucus hypersecretion and inflammation.
What are typical symptoms of chronic bronchitis?
Persistent productive cough dyspnea
What characterizes asthma?
Episodic bronchoconstriction due to airway hyperresponsiveness and inflammation.
What is atopic asthma?
An IgE-mediated hypersensitivity reaction triggered by allergens.
Describe non-atopic asthma.
Asthma without allergen sensitization often triggered by viral infections.
What is drug-induced asthma?
A form of asthma triggered by medications like aspirin causing a decrease in prostaglandin E2.
What causes bronchiectasis?
Destruction of bronchial smooth muscle and elastic tissue due to chronic infections.
What is restrictive lung disease?
A group of lung conditions with reduced lung expansion and lung volume.
List categories of chronic interstitial lung disease.
Fibrosing
Usual interstitial pneumonia (idiopathic pulmonary fibrosis)
Nonspecific interstitial pneumonia
Cryptogenic organizing pneumonia
Connective tissue disease-associated
Pneumoconiosis
Drug reactions
Radiation pneumonitis
Granulomatous
Sarcoidosis
Hypersensitivity pneumonitis
Eosinophilic
Smoking Related
What is idiopathic pulmonary fibrosis (IPF)?
A progressive lung disease with interstitial fibrosis and respiratory failure.
Describe pulmonary embolism.
Obstruction of the pulmonary artery by emboli often thrombi from deep leg veins.
What is the main cause of pulmonary hypertension?
Elevated pulmonary artery pressure due to increased resistance or blood flow.
Define lung carcinoma.
A primary malignant tumor of the lung often associated with smoking and environmental factors.
What are the main types of lung carcinoma?
Adenocarcinoma squamous cell carcinoma
What is a carcinoid tumor?
A low-grade malignant tumor of neuroendocrine cells representing 1-5% of lung tumors.
What symptoms are associated with carcinoid tumors?
Cough hemoptysis
What is pneumonia?
An infection of the lung parenchyma that occurs when normal lung defenses are impaired.
What are common causes of impaired lung defenses that lead to pneumonia?
Impaired cough reflex damage to the mucociliary escalator
List the clinical features of pneumonia.
Fever and chills productive cough with yellow-green (pus) or rusty (bloody) sputum
How is pneumonia diagnosed?
Through chest X-ray sputum Gram stain and culture
What are the three classic patterns of pneumonia on chest X-ray?
Lobar pneumonia bronchopneumonia
Define lobar pneumonia.
Characterized by consolidation of an entire lobe of the lung.
What are the most common bacterial causes of lobar pneumonia?
Streptococcus pneumoniae (95%) and Klebsiella pneumoniae.
What are the four classic stages of lobar pneumonia?
Congestion red hepatization
What is congestion in lobar pneumonia?
Vascular engorgement and edema due to congested vessels.
Describe red hepatization in lobar pneumonia.
Exudate neutrophils
What characterizes bronchopneumonia?
Scattered patchy consolidation centered around bronchioles; often multifocal and bilateral.
What organisms are commonly associated with bronchopneumonia?
Staphylococcus aureus Haemophilus influenzae
Define interstitial (atypical) pneumonia.
Characterized by diffuse interstitial infiltrates often with mild upper respiratory symptoms.
What are the typical symptoms of interstitial pneumonia?
Relatively mild symptoms such as minimal sputum production and low-grade fever.
What types of organisms cause interstitial pneumonia?
Bacteria or viruses such as Mycoplasma pneumoniae and Chlamydia pneumoniae.
What is aspiration pneumonia?
Pneumonia due to inhalation of oropharyngeal contents commonly seen in alcoholics and comatose patients.
What bacteria are most often associated with aspiration pneumonia?
Anaerobic bacteria in the oropharynx including Bacteroides fusibacterium
What is the most common cause of community-acquired pneumonia?
Streptococcus pneumoniae usually seen in middle-aged adults and elderly.
What groups are commonly affected by Klebsiella pneumoniae?
Malnourished and debilitated individuals such as the elderly in nursing homes
What unique characteristic does Klebsiella pneumoniae pneumonia have?
It produces a thick mucoid capsule resulting in gelatinous or “currant jelly” sputum.
What complication is often associated with Klebsiella pneumoniae?
Lung abscess formation.
What is a high-yield association for Staphylococcus aureus pneumonia?
It is the most common cause of secondary pneumonia often following viral respiratory infections
What is Haemophilus influenzae commonly associated with?
Community-acquired pneumonia especially in those with chronic obstructive pulmonary disease (COPD).
What is a common cause of pneumonia in cystic fibrosis patients?
Pseudomonas aeruginosa.