Respiratory Pathology 1

Basic Concepts

• Respiratory systems have the main function of moving oxygen into body tissues and removing carbon dioxide
• Aerobic exercise is not a type of respiration
• Breathing, cellular respiration, and respiratory systems are all related to respiration

Parts of the Respiratory System

• The respiratory system includes trachea, bronchi, and alveoli, but not esophagus
• Surfactant prevents alveolar walls from collapsing and sticking together
• The entire respiratory tract is lined by pseudostratified ciliated columnar epithelium

Pulmonary Infections

• Pneumonia is characterized by infection in the lung parenchyma
• Pneumonia can develop when defense mechanisms are impaired
• Pneumonia can lead to complications such as abscess formation, pleural empyema, and organization & fibrosis

Types of Pneumonia

• Bronchopneumonia and lobar pneumonia are types of pneumonia based on anatomic classification
• Viral pneumonia is not a type of pneumonia based on anatomic classification
• Bronchopneumonia is often a complication of bronchiolitis or chronic bronchitis and is characterized by multiple foci of isolated acute consolidation

Pneumonia Pathogens

• Streptococcus pneumoniae is the most common cause of community-acquired acute pneumonia
• Mycoplasma pneumoniae is commonly associated with community-acquired atypical pneumonia
• Nosocomial pneumonia is often caused by methicillin-resistant Staphylococcus aureus

Clinical Features and Outcomes

• Pneumonia symptoms include high fever, shaking chills, and pleuritic chest pain
• Complications of pneumonia include abscess formation, pleural empyema, and organization & fibrosis

Community-Acquired Acute Pneumonias

• The right middle lobe and lower lobe are frequently involved in community-acquired acute pneumonia
• S. pneumoniae pneumonia evolves through four stages

Bronchopneumonia

• Bronchopneumonia often affects infants and elderly
• Staphylococcus, Streptococcus, and Pneumococcus are common etiologies of bronchopneumonia
• Rhinovirus is not a common etiology of bronchopneumonia

Aspiration Pneumonia

• Aspiration pneumonia is partly caused by chemical injury and bacterial infection
• A common complication of aspiration pneumonia is abscess formation

Lung Abscess

• A lung abscess is characterized by necrosis of lung tissue
• The most frequent cause of lung abscess is aspiration of infective material
• Clinical features of lung abscess include copious foul-smelling purulent sputum, hemoptysis, and spiking fever

Chronic Pneumonia

• Mycobacterium tuberculosis is associated with chronic pneumonia
• Granulomatous chronic pneumonia can be caused by Histoplasma capsulatum, Coccidioides immitis, and Blastomyces dermatitidis

Pneumonia in Immunocompromised Hosts

• Pneumonia in immunocompromised hosts can be caused by Cytomegalovirus, Pneumocystis jiroveci, and Mycobacterium avium-intracellulare

Clinical Presentation

• Typical community-acquired acute pneumonia presents with high fever and shaking chills
• Atypical pneumonia typically presents with moderate amounts of sputum

Diagnosis and Treatment

• A common diagnostic feature of community-acquired acute pneumonia on a chest X-ray is consolidation of lung lobes
• The primary treatment for bacterial pneumonia typically involves antibiotics

Test your understanding of basic biology concepts, including respiratory systems and cellular respiration. Identify the main functions of these systems and distinguish between different types of respiration.