Name ____________________________________________ Comparative Animal Physiology Quiz 7 Fall, 2012 1. The air sacs in birds function primarily as A. the principle sites of gas exchange. B. dead air space where carbon dioxide is added to the air, but oxygen is not absorbed. C. parabronchi. D. holding sacs that facilitate one-way flow of air through the lungs. 2. During inhalation in humans, the pressure in the thoracic cavity _____________________ when the diaphragm _____________________. 3. Which of the following statements is true concerning "counter-current" flow. A. It occurs in both the fish gill and the avian lung. B. It allows the last segment of a gas-exchange capillary to come into contact with the highest concentration of oxygen. C. It can only produce a maximum blood oxygen concentration equal to one-half the concentration in the water. D. none of the above are true. 4. to the During the bird respiratory cycle, inhaled air moves from the mouth to the trachea, and then A. posterior air sacs B. lung C. anterior air sacs D. parabronchi 5. In terms of obtaining oxygen from the environment, amphibians rely on their lungs and _________________________________. 6. Which of the following statements is true? A. both the mammalian lung and the avian lung contain air capillaries. B. both the mammalian lung and the avian lung have alveoli. C. both the mammalian lung and the avian lung have dead air spaces. D. only the mammalian lung has parabronchioles. 7. The pleural membranes (visceral and parietal) are important because. 8. Imagine that a person begins holding her/his breath. Carbon dioxide will begin to accumulate in the blood. Explain the steps that will ultimately cause the cardiac center to increase respiratory rate. Be sure to include any relevant chemistry. (4 points) 9. What is an example of an animal that uses "positive pressure breathing?" 10. In terms of gas exchange, how would you define "ventilation?" 11. What is the purpose of surfactant in the lung?