Lungs & Thorax

• Collapsed shrunken section of alveoli or entire lung. Result of:
• Airway obstruction (exudate, aspirated, foreign body/tumor)
• Compression on the lung
• Lack of surfactant.

Infection in lung leaves alveolar membrane edematous and porous. Red blood cells and white blood cells pass from blood to alveoli. Alveoli progressively fill up (consolidated) with bacteria, debris, fluid, and blood cells, which replace alveolar air. Decreased surface area of respiratory membrane ->hypoxemia.

Proliferation of mucous glands in the passageways, resulting in excessive mucus secretion. Inflammation of bronchi with partial obstruction of bronchi by secretions or constrictions. Caused by cigarette smoking.

Caused by destruction of pulmonary connective tissue(elastin; collagen) Permanent enlargement of air sacs distal to terminal bronchioles, rupture of inter-alveolar walls. Increases airway resistance on expiration. Produces hyperinflated lung, increase in lung volume. Cigarette smoking.

Allergic hypersensitivity to allergens, irritants, microoorganisms, stress, or exercise. Brochospasm, inflammation, edema in walls of bronchioles, and secretion of viscous mucus into airways. Increases airway resistance during expiration. Wheezing, dyspnea, and chest tightness.

Pump failure with increasing pressure of cardiac overload causes pulmonary congestion or increased amount of blood in pulmonary capillaries. Dependent air sacs deflate. Pulmonary capillaries engorged. Bronchial mucosa may be swollen.

• Free air in pleural space causes partial or complete lung collapse. Air in space neutralizes the negative pressure present; lung collapses.
• Spontaneous: air enters space through rupture in lung wall
• Traumatic: through opening or injury in chest wall
• Tension: Trapped air in pleural space increases, compressing lung and shifting mediastinum to unaffected side.

Inhalation of tubercle bacilli. Initial complex is acute inflammatory response. Scar tissue forms, lesion calcifies on x-ray. Reactivation of previously healed lesion, bacilli multiply, producing cheese like lung tissue. Extensive destruction at lesion erodes onto bronchus. Apex has most damage.

Undissolved materials originate in legs or pelvis, detach and travel through blood to right heart and lodge to occulde pulmonary vessel. DVT in lower leg. Ischemia of downstream lung tissue, decrease cardiac output, and hypoxia.