Final answer:
In chronic bronchitis, goblet cells enlarge and secrete excess mucus, which leads to symptoms such as a persistent cough and difficulty breathing.
Step-by-step explanation:
In chronic bronchitis, the cells that enlarge and secrete excess mucus are called goblet cells. Goblet cells are specialized epithelial cells found in the lining of the respiratory tract. When a person has chronic bronchitis, the bronchial walls become inflamed and irritated, causing an overproduction of mucus by the goblet cells.
This excessive mucus production can lead to a persistent cough and difficulty breathing, as the airways become obstructed by the excess mucus. The mucus serves as a protective mechanism to trap and remove foreign particles, but in chronic bronchitis, the mucus production becomes excessive and causes symptoms.
For example, in the bronchi and bronchioles of the lungs, goblet cells secrete mucus as a response to irritants such as cigarette smoke or pollutants. The excess mucus can narrow the airways, making it harder for air to flow and leading to symptoms of chronic bronchitis.