Breathing+Questions+SLS


 * Mechanism of Breathing pp. 174-176**

Inspiration is the active phase of ventilation because this is the phase where the diaphragm and the external intercostal muscles contract. (Moves air into the lungs.) In doing so, the volume of the thoracic cavity will be larger. Expiration (moves air out of the lungs) is the passive phase of breathing, and no effort is required. The lungs recoil because the surface tension of the fluid lining the alveoli tends to draw them closed.
 * 1. Define inspiration, expiration.**

The intercostal muscles are several groups of muscles that help form and move the chest wall.
 * 2. Where are the intercostal muscles?**

The diaphragm is located under the lungs and the heart.
 * 3. Where is the diaphragm muscle?**

The thoracic cavity is a chamber in the human body that hold the heart. It is considered sealed because it is separated from the rest of the abdominal cavity.
 * 4. The lungs are in a "sealed" off thoracic cavity. Describe this cavity. Why is it considered "sealed"?**

During inspiration the diaphragm becomes a flat sheet of muscle, which is called contraction. The external intercostal muscles also contract, causing the ribcage to move upward and outward.
 * 5. Describe the diaphragm and intecostal muscles during inspiration.**

The creation of a partial vacuum in the alveoli causes air to enter into the lungs.
 * 6. Air does NOT force open the lungs. So why does air enter the lungs?**

There is no effort needed using expiration, but the thoracic wall and lungs recoil due to their elastic properties. The lungs recoil because the surface tension of the fluid lining the alveoli tends to draw them closed.
 * 7. Passive Recoil occurs during expiration. What does that mean?**

Air is pushed out during expiration because the pressure inside of the lungs increase.
 * 8. Why is air pushed out during expiration?**

You can achieve maximum inspiratory effort by expanding the chest and lowering the diaphragm.
 * 9. How can you achieve maximum inspiratory effort?**

Contracting the abdominal and thoracic muscles.
 * 10. How can you force expiration which is usually passive?**

You do not use your total lung capacity when you breathe. You use vital capacity, which is the maximum amount of air that can be moved in and the maximum that can be moved out.
 * 11. Do you use your total lung capacity when you breathe? What do you use?**

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

It is better to breathe slowly and deeply.
 * 13. How should you breathe to get the most fresh air to your alveoli? Why?**