Advanced Dental Admission Test (ADAT)

What is a key function of Clara cells in the respiratory system?

1. Secrete mucous

2. Produce surfactant

3. Increase pulmonary compliance

4. Absorb oxygen

The correct answer is: Increase pulmonary compliance

Clara cells, also known as club cells, play an important role in the respiratory system, particularly within the bronchioles. However, the key function of Clara cells is not correctly represented in the chosen answer. Clara cells primarily serve to secrete a variety of substances, including components of the surfactant mixture and enzymes that help to detoxify inhaled substances. They contribute to the maintenance and repair of the bronchiolar epithelium, as well as playing a role in sequestering various harmful agents. Surfactant production, which reduces surface tension within the alveoli and is crucial for keeping the airways open, is primarily the function of type II alveolar cells. The production and secretion of mucus is more closely associated with goblet cells and other specialized epithelial cells in the respiratory tract. The absorption of oxygen occurs in the alveoli primarily through type I alveolar cells, which facilitate gas exchange. Therefore, the most accurate function associated with Clara cells is related to their secretory role and support in the respiratory system's overall function rather than increasing pulmonary compliance.