Explain Abnormal Lung Physiology COPD

5 a] Explain Abnormal Lung Physiology COPD

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease characterized by abnormal lung physiology. It primarily affects the airways and air sacs (alveoli) in the lungs, leading to impaired airflow and difficulty breathing. Here’s an explanation of the abnormal lung physiology associated with COPD:

1. Chronic Inflammation: In COPD, there is a persistent inflammation of the airways and lung tissue. This inflammation is often caused by exposure to irritants, such as cigarette smoke, air pollution, or occupational dust and chemicals. The chronic inflammation damages the delicate lung tissue and triggers a cascade of events that contribute to the disease’s progression.
2. Airway Narrowing: The inflammation in the airways leads to the thickening of their walls and an increase in mucus production. This narrows the air passages, making it harder for air to flow in and out of the lungs. The narrowed airways are particularly problematic during exhalation.
3. Loss of Elasticity: In a healthy lung, the alveoli are elastic and can expand and contract easily with each breath. In COPD, the chronic inflammation and tissue damage lead to a loss of lung elasticity. This results in decreased lung compliance, making it more difficult to inhale and exhale effectively.
4. Destruction of Alveoli: One hallmark feature of COPD is the destruction of alveoli, which are responsible for exchanging oxygen and carbon dioxide in the bloodstream. This damage is often referred to as “emphysema.” As alveoli are destroyed, the surface area available for gas exchange decreases, leading to decreased oxygen uptake and impaired removal of carbon dioxide.
5. Increased Air Trapping: Due to the narrowing of the airways and the loss of elasticity, individuals with COPD often experience air trapping. During exhalation, the damaged lungs are less effective at expelling air, resulting in residual air being left in the lungs. This trapped air can cause the characteristic “barrel chest” appearance in some individuals with advanced COPD.
6. Difficulty Exhaling: COPD primarily affects the expiratory phase of respiration. Individuals with COPD have a harder time exhaling completely due to the narrowed airways and loss of lung elasticity. This leads to increased residual volume and hyperinflation of the lungs.
7. Reduced Oxygen Exchange: As COPD progresses, the lung’s ability to exchange oxygen and carbon dioxide becomes severely compromised. This results in decreased oxygen levels in the bloodstream (hypoxemia) and elevated levels of carbon dioxide (hypercapnia), which can lead to symptoms like shortness of breath, fatigue, and cyanosis (bluish discoloration of the lips and skin).
8. Exacerbations: COPD symptoms often worsen periodically, known as exacerbations. These episodes are typically triggered by infections, environmental factors, or other stressors and can lead to further lung function decline.