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BIO 140 Human Biology I - Questions and Solutions

Gas Exchange - Solutions

Review Questions

1. Gas moves from an area of ________ partial pressure to an area of ________ partial pressure.

  1. low; high
  2. low; low
  3. high; high
  4. high; low

2. When ventilation is not sufficient, which of the following occurs?

  1. The capillary constricts.
  2. The capillary dilates.
  3. The partial pressure of oxygen in the affected alveolus increases.
  4. The bronchioles dilate.

3. Gas exchange that occurs at the level of the tissues is called ________.

  1. external respiration
  2. interpulmonary respiration
  3. internal respiration
  4. pulmonary ventilation

4. The partial pressure of carbon dioxide is 45 mm Hg in the blood and 40 mm Hg in the alveoli. What happens to the carbon dioxide?

  1. It diffuses into the blood.
  2. It diffuses into the alveoli.
  3. The gradient is too small for carbon dioxide to diffuse.
  4. It decomposes into carbon and oxygen.

 

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Critical Thinking Questions

1. Compare and contrast Dalton’s law and Henry’s law.

Solution: Both Dalton’s and Henry’s laws describe the behavior of gases. Dalton’s law states that any gas in a mixture of gases exerts force as if it were not in a mixture. Henry’s law states that gas molecules dissolve in a liquid proportional to their partial pressure.

2. A smoker develops damage to several alveoli that then can no longer function. How does this affect gas exchange?

Solution: The damaged alveoli will have insufficient ventilation, causing the partial pressure of oxygen in the alveoli to decrease. As a result, the pulmonary capillaries serving these alveoli will constrict, redirecting blood flow to other alveoli that are receiving sufficient ventilation.

 

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OpenStax, Gas Exchange. OpenStax CNX. Feb 6, 2017 http://cnx.org/contents/98519dc2-a601-4193-a1e9-844a560771a4@7. © Feb 6, 2017 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License 4.0 license.