Question 6

1. Assume that the flow at the level of the trachea is 500 milliliter per second, and that tracheal diameter is 2 cm.
   What is the gas speed in the trachea?
2. Now look at the bottom illustration. The vertical axis shows how surface area increases from the trachea to the smaller airways.
3. Estimate gas speed at the 10th generation.
   Also estimate gas speed at the alveolar level, say at generation 20.
4. The top figure illustrates the deposition pattern of particles in the airways as a function of particle diameter.
   Pollen are larger than 10 µm, mostly between 20-50 µm.
   How far do they penetrate into the airways, where in the airway do they impact?
5. Assume that a particle has a diameter of 10 µm: how much more mass does it bring to the airway than a 1 µm particle?