Emphysema Overview and Lung Dynamics

Emphysema

• Characterized by dilated airspaces in the lungs, particularly in the upper fields.
• Loss of alveolar walls leads to enlarged airspaces, contrasting with normal lung structure.
• Classified as a Chronic Obstructive Pulmonary Disease (COPD) due to airflow limitation, despite not being obstructive in the peripheral airways.

Mechanisms of Respiratory Movements

• Emphysema leads to hyperinflation due to destroyed alveolar septa, inhibiting the ability to expel air during expiration.

Types of Chronic Lung Diseases

• Chronic Bronchitis: Glandular hyperplasia and excess mucus from tobacco smoke; common symptoms include cough and sputum production.
• Bronchiectasis: Airway dilatation and scarring due to persistent infections; presents with purulent sputum and fever.
• Asthma: Smooth muscle hypertrophy and excess mucus lead to episodic wheezing and dyspnea.
• Emphysema: Characterized by acinar airspace enlargement.

Pneumonia

• Also known as pneumonitis; inflammation can lead to permanent changes in lung vessels if hypoxia persists.
• Pneumonia classified as lobar (affects entire lobes) or bronchopneumonia (scattered foci around bronchi).
• Predominantly caused by bacterial infections, especially Streptococcus pneumoniae; risk factors include smoking, chronic conditions, and poor immune response.

Pulmonary Oedema

• Fluid presence in alveolar spaces, resulting from hemodynamic changes or increased vascular permeability.
• Symptoms include heavy, water-logged lungs that may lead to respiratory failure.
• Causes of hemodynamic oedema include left-sided heart failure and volume overload; increased permeability may result from infections or chemicals.

Atelectasis

• Defined as the collapse of expanded lung tissue, which can be categorized into:
  • Obstructive: Complete airway blockage leads to absorption of trapped oxygen.
  • Compressive: Fluid, tumors, or air fills the pleural cavity.
  • Patchy: Loss of surfactant or lung trauma.
  • Contraction: Lung retraction due to fibrosis.

Pulmonary Hypertension

• Increased arterial blood pressure within the pulmonary vasculature, potentially idiopathic or secondary.

Pleural Disorders

• Pleural effusion: Excess fluid in the pleural space, detected clinically at around 500 mL; can be categorized into transudate (lower protein) or exudate (higher protein).
• Empyema: Collection of pus in pleural cavity, often secondary to pneumonia.
• Haemothorax: Blood collection due to trauma or other injuries.
• Chylothorax: Opalescent lymph contributes to pleural accumulation, typically from thoracic duct obstruction.
• Pneumothorax: Air accumulation in pleural space, often from lung bulla rupture or chest injury.

Malignant Mesothelioma

• Cancer linked to asbestos exposure, primarily affecting pleura and is more common in males over 40.
• Symptoms include dyspnea, pleural effusion, chest pain, weight loss, cough, and fever; prognosis is poor with most patients succumbing within a year.

Morphology of Pleural Tumors

• Generally unilateral, originating as small nodules, progressing to cover the entire lung.
• Microscopically classified into epithelioid, sarcomatoid, and mixed types.

This quiz explores the characteristics of emphysema, focusing on the dilated airspaces observed in lung sections and comparing the dynamics of respiration in individuals with emphysema to normal lungs. Understand the differences in alveolar structures and their implications on respiratory function.