Respiratory Tract Flashcards
Nasopharynx
Nose to throat
Respiratory epithelium
Pharynx
Nasopharynx + oropharynx
Squamous epithelium
Larynx
Starts at epiglottis and contains vocal cords
Squamous epithelium
Trachea
Only part of the middle respiratory tract
Respiratory epithelium
Respiratory epithelium
Cuboidal epithelium
Ciliated cells, mucous producing cells, neuroendocrine cells, reserve (progenitor) cells
Protective role
Alveoli
Lined by pneumocytes
Type 1 and Type 2
Type 1 pneumocytes
Air exchange cells
Type 2 pneumocytes
Surfactant producing cells
Surfactant
Increases surface tension, allowing alveoli to remain open
Upper respiratory tract infections
The common cold
Caused by viruses (rhinoviruses, influenze, parainfluenza)
Self-limited, do not need antibiotics
Acute inflammation of nose, paranasal sinuses, larynx, pharynx
Viral pneumonia
URI going to lungs
Usually in immunocompromised
Otitis media
URI going to middle ear
Middle respiratory tract infection
Infection of laryx, trachea and mainstem bronchi
Most common among children
Results from extension of URI, may be associated with pneumonia
Can be life threatening to adults
Laryngitis
MRI
Croup
Inflammation of larynx causing stridor and barking cough
Parainfluenza virus
Acute epiglottitis
MRI
Haemophilus influenzae
Immunization is standard
Life threatening
Viral trachaeobronchitis
MRI
Bronchiolitis
MRI
More lower, but not aveoli
Lower respiratory tract infections
Pneumonia
Bacteria, viruses, fungi
Alveolar or interstitial pneumonia
Alveolar pneumonia
Caused by bacteria
Focal or diffuse
Neutrophils and exudate in alveolia
Bronchopneumonia
Focal alveolar pneumonia
Lobar pneumonia
Diffuse alveolar pneumonia
Interstitial pneumonia
Caused by viruses or Mycoplasma pneumonia (atypical bacteria)
Diffuse and bilateral
Alveolar septal thickening with macrophages and lymphocytes
Needs to be cultured
Pathogenesis of pneumomia (4)
- Inhalation of pathogens as air droplets
- Aspiration of infected secretions from URT
- Aspiration of gastric contents
- Hematogenous spread (bacteriemia, sepsis)
Clinical features of pneumonia
Fever, chills
Cough
Airway obstruction, shortness of breath, rapid breathing
Inflammation and tissue destruction, bloody cough
Dyspnea
Shortness of breath
Tachypnea
Rapid breathing
Hemoptysis
Bloody couch
Common causes of pneumonia (4)
- Bacteria
- Viruses
- Fungi
- Bacteria-like organisms
Complications of pneumonia (4)
- Scar tissue
- Pus in pleural space
- Large collection of neutrophils with destruction of tissue
- Chronic changes in lung parenchyma
Pulmonary tuberculosis
M. tuberculosis with tiny rod-shaped bacteria with acid-resistant coating Gramulomatous reactions (nodules of multinucleated macrophages and lymphocytes with central necrosis)
Primary pulmonary tuberculosis infection
Localized lung lesion - Ghon’s complex
Enlarged lymph nodes
Heals but dormant bacteria may be present
Secondary tuberculosis
Reactivated infection
Bacteria spread to lung apices
Cause granulomatous pneumonia
Widespread dissemination of TB
Hematogenous, lymphatic or via airways
Miliary TB in lungs, pleuritis, extrapulmonary granulomas
Asthma
Inflammatory condition
Increased responsiveness of bronchi to variety of stimuli
Intrinsic, extrinsic
Asthma attacks
Most common chronic disease of children, resolves spontaneously in adults
Intrinsic (non-atopic) asthma
Heat/cold, exercise, chemical irritant, psychological stress, infection
Extrinsic (atopic) asthma
Exposure to exogenous allergens
Type 1 hypersensitivity reactions - mediators of inflammation
Associated with food allergies, dermatitis, usually in children
Over time - smooth muscle and mucous gland hyperplasia
Chronic obstructive lung disease
COPD
Term for lung diseases causing chronic airway obstruction
Including chronic bronchitis and emphysema
Vast majority caused by smoking
Chronic bronchitis
Excessive production of bronchial mucous causing productive cough, must be 3mo over 2 years
Permanent dilation of bronchi caused by persistent inflammation
Mucous material stagnates, cannot be cleared
Scarring in lungs, pulmonary hypertension, right sided heart failure
Cyanosis and fluid retention
Bronchiectasis
Permanent dilation of bronchi due to persistent inflammation
Cyanosis
Decreased oxygen to peripheries
Emphysema
Enlargement of the air spaces distal to the terminal bronchioles
Destruction of alveolar walls
No productive cough
Reduced respiratory surface with compensatory tachypnea
Over expanded and overinflated chest - barrel chest
Pneumoconioses
Lung diseases caused by inhalation of dust, fumes, inorganic and organic matter
Lung injury depends on size/qualities of particles, concentration and duration
Asbestosis
Pneumoconioses due to asbestos
Usually large and retain in nose
Lung lesions associated with asbestos (4)
- Pulmonary fibrosis (shortness of breath)
- Pleural fibrosis, pleural plaques (asymptomatic)
- Lung cancer
- Mesothelioma
Most common neoplasms of the RT (2)
- Carcinoma of the larynx
2. Lung carcinoma
Carcinoma of the larynx
Older age, male, smoking, alcohol
Vocal cords
Lung carcinoma
Most common malignant tumor of internal organs
Smoking
Small cell carcinoma, non-small cell carcinoma
Poor prognosis
Usually from bronchiole tree
Carcinogenic
Activation of oncogenes and/or activation of tumor suppressor genes
Irritant
Causes metaplasia
Types of lung carcinoma (2)
- Small cell carcinoma
2. Non-small cell carcinoma
Small cell carcinoma
Precursor: neuroendocrine cell
Non-small cell carcinoma (3)
- Squamous cell carcinoma
- Adenocarcinoma
- Large-cell undifferentiated carcinoma
Clinical features of lung cancer (4)
- Bronchial irritation
- Local extension into pleural cavity, pleural effusion and shortness of breath
- Distant metastasis
- Systemic affects
Metastatic cancer to lung
Even more common than primary lung cancer
May present as solitary lesion, multiple lesions, diffuse involvement of lungs
Pleural disease (4)
- Pneumothorax
- Pleural effusion
- Epyema
- Mesothelioma
Mesothelioma
Rare tumor from pleural cells (parietal or visceral)
Linked to asbestos exposure but can be sporadic
Poor prognosis
