Gas exchange occurs in which of the following structures?

A. Asthma is a chronic respiratory condition characterized by inflammation and hyperresponsiveness of the airways. This inflammation leads to bronchoconstriction, causing symptoms like wheezing, shortness of breath, chest tightness, and coughing. This description accurately captures the primary pathological features of asthma.
B. Fluid in the lungs, also known as pulmonary edema, is not a characteristic of asthma. Pulmonary edema is usually associated with conditions such as heart failure or acute respiratory distress syndrome (ARDS), not asthma.
C. Airway stretching and nonfunctionality are not characteristics of asthma. Conditions like bronchiectasis involve permanent dilation and damage to the airways, leading to chronic infections and impaired clearance of mucus, but this is different from asthma.
D. Asthma is not primarily caused by an infection, although infections can trigger asthma exacerbations. The primary issue in asthma is chronic inflammation and hyperresponsiveness of the airways, which are not caused by a low-grade infection but by a combination of genetic and environmental factors.

B. Bronchodilators are medications commonly used to relieve bronchospasm and improve airflow in patients with COPD. They work by relaxing the muscles around the airways, making it easier to breathe. Providing bronchodilators as prescribed can help alleviate difficulty breathing and improve the patient's respiratory function.
D. Smoking cessation is essential for patients with COPD as smoking is the leading cause of the disease and can exacerbate respiratory symptoms. Quitting smoking can slow the progression of COPD, reduce the frequency and severity of exacerbations, and improve overall lung function.
E. Corticosteroids are anti-inflammatory medications commonly used to reduce airway inflammation and control exacerbations in patients with COPD. They can help improve breathing and reduce the severity of respiratory symptoms during acute exacerbations.
A. Offering small frequent meals can help reduce the sensation of fullness and bloating, which can sometimes occur in patients with COPD due to increased abdominal pressure from compromised respiratory function. However, this is not specific to COPD.
C. Weaning from oxygen should be done cautiously and under the guidance of healthcare providers but not in the state of difficulty in breathing. Oxygen therapy is often necessary for patients with COPD who experience difficulty breathing, especially during acute exacerbations. Therefore, weaning from oxygen may be appropriate once the patient's respiratory status stabilizes and oxygen saturation levels improve.