Because of changes in regional blood flow, bed rest decreases the amount of surfactant produced. (Surfactant enables the alveoli to remain open.) The combination of decreased surfactant and blockage of a bronchiole with mucus can cause ___ (the collapse of a lobe or of an entire lung) a. Decreased respiratory movement. b. Pooling of respiratory secretions. c. Atelectasis. d. Hypostatic pneumonia