What is chronic bronchitis? What is the difference between chronic bronchitis and COPD?
The lung has a series of branching tubes that deliver air to and from the atmosphere to the alveoli. These tubes are called bronchi. The cells that line the bronchi are made up of special cells with hairy filaments on them called cilia, as well as special cells that secrete mucus. The function of these cells is to protect the lung from pollutants, allergens, and micro-organism that we inhale from the environment. Smoking can damage the ciliated cells and causes abnormal growth of the mucous cells, thus, the lung starts secreting excess mucus while the ciliated cells lose their ability to push the mucus along. The result is chronic bronchitis, where the patients have excessive amounts of mucus in the lung and the only way to get rid of the mucus is to cough. The cough is usually worsened in the morning. Also, the damage in the cilia predisposes the patient to frequent infections, where the sputum becomes yellow or green after invasion by bacteria. We refer to these infections as COPD ex
