Advanced Dental Admission Test (ADAT) 2026 – The Complete All-in-One Study Guide for Exam Success!

The correct answer highlights the role of mesothelial cells, which line the pleural cavity and produce a serous fluid. This fluid has a significant function in reducing friction between the lungs and the thoracic wall during breathing. By creating a lubricated surface, mesothelial cells help facilitate smooth movements as the lungs expand and contract, ultimately aiding in respiratory efficiency.

Goblet cells primarily produce mucus, which serves to trap particles and pathogens in the respiratory tract, but they do not directly reduce friction or surface tension in the lungs. Clara cells, found in the bronchioles, have protective functions and produce surfactant-like substances, but they do not primarily line the pleural space. Kulchitsky cells are neuroendocrine cells that are involved in hormone secretion and may play roles in response to stress but are not directly responsible for minimizing friction or surface tension in the lungs. Thus, mesothelial cells are key to the lubrication required for effortless lung movement.