Flow in the Lungs - Biofluidmechanics: An Introduction to Fluid Mechanics Macrocirculation and Microcirculation - page 275

there is an ineffective transport of gases between the alveolar space and the cardiovascular
system. Tuberculosis is characterized by an infection within the lungs that can either increase
the resistance to air movement or break down the respiratory boundary.

HOMEWORK PROBLEMS
9.1 Describe the passage of air from the nose to the alveoli and discuss some of the important
structures within the respiratory system. Pay close attention to the structure-function rela-
tionship of the organs.
9.2 Describe the mechanism of breathing, paying close attention to the movement of the ribs
and the diaphragm.
9.3 The surfactant along the alveolar wall is present to prevent the alveoli from collapsing.
How does this fluid perform this function?
9.4 Gas exchange along the alveolar wall occurs rapidly and efficiently because the driving
forces are large, oxygen and carbon dioxide are lipid soluble, and the surface area for diffu-
sion is large. Describe the role of each of these during exchange.
9.5 The bronchioles in the respiratory system are analogous to the arterioles in the cardiovascu-
lar system. How?
9.6 The differences between the atmospheric, the interpulmonary, and the intrapleural pres-
sures determine the direction of air flow within the lungs. How would this change at dif-
ferent elevations where the atmospheric pressure could change drastically?
9.7 Under a disease condition, the separation distance for the alveolar gas and the capillary gas
can be described as

<
:

0 Δ P ,2 0 : 7 mmHg

0 : 5 μ m

0 : 5 μ m 1

5 mmHg Δ P

2 0 : 7 mmHg , Δ P , 0 mmHg

:

0

h ðΔ P Þ 5

μ

m
50 mmHg Δ P

2

0 : 5 μ m 1 0 mmHg , Δ P , 30 mmHg

1 : 7 μ m Δ P . 30 mmHg

Plot separation distance h as a function of pressure and compare this with the normal case.
What has happened under these conditions, and what are some of the possible characteris-
tics of the disease?
9.8 Under exercise conditions, predict what the tidal volume would be. Why would this be
necessary? Where would the extra volume be taken from: the inspiratory reserve volume
or the expiratory reserve volume or both?
9.9 What would happen if there was no residual volume within the lungs?
9.10 The solubility coefficient for carbon dioxide is an order of magnitude larger than the solu-
bility coefficient for oxygen. What does this suggest about gas transport within the blood,
and is this accounted for by the known processes of gas transport in the blood?