Pneumonia: SAQ Solutions

Listed below are the solutions to the SAQs on Pneumonia:

1. C. Cartilage
   The tracheal cartilage is in C-shaped rings, which allows it flexibility and slight diameter changes while also providing structural rigidity. Muscle composition would not provide adequate rigidity of the trachea, while bone would not provide the necessary flexibility.
2. Contract; Relaxes
   The diaphragm contracts downward in the thoracic cavity to expand its volume. This causes air to move into the lungs down its pressure gradient by Boyle’s law. Relaxation of the diaphragm, then, restricts this thoracic volume again upon exhalation.
3. The alveoli
   Because alveoli are the site of gas exchange with the pulmonary capillaries, their infection inflammation upon infection is particularly detrimental to lung function. These infections give rise to pneumonia.
4. B. Tracheal constriction
   Pneumonia affects the respiratory zone of your lungs. While the trachea can change diameter (see question 1), it is part of the conduction zone and is thus not affected by pneumonia like the other answer choices.