1. Chapter 28 Respiration

2. I. Introduction A. Functions of the respiratory system 1. Works in conjunction with the circulatory system 2. Provides oxygen for cellular respiration B. The respiratory system and smoking

3. II. Evolution of the respiratory system A. Gas exchange in all organisms depends on diffusion 1. The respiratory surface must remain moist 2. The respiratory system must have a large surface area

4. II. Evolution of the respiratory system B. Changes in the respiratory system needed to accommodate organisms 1. Increase in surface area of the organisms over time 2. Conversion from aquatic to terrestrial environments

5. III. Respiratory systems and gas exchange A. Interrelated with circulatory system B. Mechanisms of gas movement 1. Bulk flow from areas of higher pressure to areas of lower pressure 2. Simple diffusion at the tissue or lung level

6. III. Respiratory systems and gas exchange C. Gas exchange in aquatic environments—gills D. Gas exchange in terrestrial environments 1. Book lungs 2. Tracheae 3. Lungs

7. IV. Human respiratory system A. The conducting portion 1. Carries air to the lungs 2. Warms and moistens air moving through it 3. Cilia that line the trachea, bronchi, and bronchioles filter dust particles

8. IV. Human respiratory system B. Gas exchange portion 1. The alveoli have an enormous surface area 1. The alveoli have an enormous surface area 2. Capillaries surround the alveoli 3. The mechanism of gas exchange and transport a. Oxygen and hemoglobin b. Carbon dioxide and bicarbonate ions

9. IV. Human respiratory system C. Mechanics of breathing 1. Inspiration—active inhalation of air a. Diaphragm and rib muscles contract, making the chest cavity larger b. Chest expansion causes the lungs to expand; vacuum draws in air

10. IV. Human respiratory system C. Mechanics of breathing (cont.) 2. Expiration—passive exhalation of air when muscles are relaxed

11. IV. Human respiratory system D. Control of respiration 1. Description of breathing 2. Regulation of breathing by carbon dioxide