Drew's+Mechanism+of+Breathing+hw

Mechanism of Breathing pp. 174-176 1. Define inspiration, expiration Inspiration-active phase of ventilation where the diaphragm and the external intercostal muscles contract Expiration-passive phase of breathing, no effort is required to bring it about

2. Where are the intercostal muscles? They are located in the ribs

3. Where is the diaphragm muscle? It is below the lungs

4. The lungs are in a "sealed" off thoracic cavity. Describe this cavity. Why is it considered "sealed"? The cavity has consists of the lungs, the rib cage, the intercostal muscles, and the diaphragm. It is sealed off from the rest of the body.

5. Describe the diaphragm and intecostal muscles during inspiration. The diaphragm and the intercostal muscles expand and make the thoratic cavity larger than normal.

6. Air does NOT force open the lungs. So why does air enter the lungs? The pressure difference creates a vacuum and forces air into the lungs.

7. Passive Recoil occurs during expiration. What does that mean? No effort is required to make it happen.

8. Why is air pushed out during expiration? The elastic properties of the thoracic wall and lungs cause them to recoil.

9. How can you achieve maximum inspiratory effort? During hard exercising

10. How can you force expiration which is usually passive? When singing, or blowing air into a trumpet.

11. Do you use your total lung capacity when you breathe? What do you use? We use about 2,900 mL and we can use up to about 5,800 mL

12. Why are the nasal cavities, trachea, bronchii, and bronchioles considered "dead air space"? These areas are not used for gas exchange

13. How should you breathe to get the most fresh air to your alveoli? Why? It is better to breathe slow