Which of the following is NOT true of the alveoli? O A. gas exchanges occur by simple diffusion O B. are composed of simple columnar epithelium O C. each have a network of capillaires surrounding them O D. None of the above O E. have Type Il cells embedded within the epithelium What is the primary function of pulmonary surfactant? D A. helps prevent the alveoli from collapsing by lubricating the alveolar membranes during exhalation B. is secreted in the nasal passages OC. phagocytizes small particulates D. replaces mucus is the alveoli E. none of the above Which of the following is TRUE of asthma? O A. all of the above O B. can be relieved with bronchodilators O C. causes dyspnea O D. may be caused by allergens or irritants O E. is due to acute bronchconstriction