2.
a) Fish are confined to a medium of water. What are the advantages and disadvantages of water as a respiratory medium as opposed to air?
b) How are fish able to maintain efficient gas exchange in the gills?

3. Trace the flow of air in a human from the point it enters the body to the point of oxygen-carbon dioxide exchange with the blood.

4. Define the following terms:
a) tidal volume -
b) vital capacity -
c) residual capacity -

5.
a) What is the relationship between volume and pressure in the lungs? Name two ways that the body alters the volume of the chest cavity. How does this allow us to breathe? Be specific.
b) Explain the differences between positive and negative pressure breathing, and give examples of organisms that use each.

6. Explain how the differences in partial pressures of carbon dioxide and oxygen affect their loading and unloading within the respiratory system.

7.
a) Draw a typical hemoglobin saturation (or oxygen dissociation) curve at pH=7.4 AND at pH = 7.2 on the same graph.
b) Explain why the two curves appear different. (Hint: Define the Bohr shift.)
c) What are the three forms that carbon dioxide can take as it is transported throughout the body? Which is the most common form?
d) Describe how increased levels of activity (like exercise) affects pH in the body.

8.
a) With regard to hemoglobin, describe the concept of cooperativity and reversibility.
b) How does carbon monoxide affect hemoglobin?

9. Diving mammals are able to remain under water for extended periods of time without coming back up for air. What kind of physiological adaptations do they have to allow this?

10. List types of respiratory receptors and their location. Which gas, carbon dioxide or oxygen, is primarily monitored by the body to maintain homeostasis?

11. At the summit of a high mountain, the atmospheric pressure is only half of its normal value of 760 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? SHOW YOUR WORK!
a. 0 mm Hg
b. 80 mm Hg
c. 160 mm Hg
d. 380 mm Hg
e. 760 mm Hg

12. During a UK game, a loyal Big Blue fan became so excited that he began to hyperventilate and eventually passed out. Immediately, he was picked up by his friends and carried to UK hospital where the doctors diagnosed him with Respiratory Alkalosis. What could his friends have done in order to prevent him from passing out and why? (note: respiratory alkalosis is a condition where the blood is too basic)