• Air passes through a series of tubes before gas exchange takes place across a very extensive moist surface.

1. What events are required in order to supply cells with oxygen and rid them of carbon dioxide?
   Answer
2. How is the air that is inhaled or exhaled modified by the respiratory surfaces?
   Answer
3. What is the path of air, and what are the functions of the organs along that path?
   Answer

Essential Study Partner

• Human Breathing

Art Labeling Activity

• The Respiratory Tract
• The Respiratory Tract II
• The Upper Respiratory Tract
• The Upper Respiratory Tract II
• Section of Larynx
• Glottis Function

• Respiration comprises breathing, external and internal respiration, and cellular respiration.
• During inspiration, the pressure in the lungs decreases, and air comes rushing in. During expiration, increased pressure in the thoracic cavity causes air to leave the lungs.

1. Why do physicians measure our ability to move air into and out of the lungs? What measurements do they take?
   Answer
2. How is breathing achieved? Is pressure within the lungs greatest during inspiration or expiration?
   Answer
3. What controls the breathing rate?
   Answer

Essential Study Partner

• Measuring Function

Animation Activity

• Breathing

• External respiration occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out of the blood.
• Internal respiration occurs in the tissues where oxygen diffuses out of the blood and carbon dioxide diffuses into the blood.
• The respiratory pigment hemoglobin transports oxygen from the lungs to the tissues and aids in the transport of carbon dioxide from the tissues to the lungs.

1. What are the differences between external respiration and internal respiration?
   Answer
2. What respiratory pigment is found in human red blood cells? How does it function in the transport of oxygen; carbon dioxide?
   Answer

Essential Study Partner

• Gas Exchange

Animation Activity

• Respiration
• Hemoglobin
• Gas Exchange
• Movement Oxygen Carbon Dioxide(English)
• Movement Oxygen Carbon Dioxide(Spanish)
• Gas Exchange

General Biology Case Studies

• Breathing Liquids: Reality or Science Fiction

• The respiratory tract is especially subject to disease because it is exposed to infectious agents.
• Smoking tobacco contributes to three major lung disorders-chronic bronchitis, emphysema, and cancer.

1. What are some common respiratory infections and disorders of the upper respiratory tract? Of the lower respiratory tract?
   Answer
2. What are three respiratory disorders commonly associated with smoking tobacco?
   Answer

Essential Study Partner

• Disorders

Animation Activity

• Smoking Risks
• Asthma

Art Labeling Activity

• Bronchial and Pulmonary Disorders

Systems Scramble

• Systems Review Quiz

Bioethical Case Studies

• Pros and Cons of Smoking Bans

General Biology Case Studies

• Asthma: The New Worldwide Epidemic