1. P HYSIO E X 37B Dr. Kim Wilson

2. O BJECTIVES To define the following terms: ventilation, inspiration, expiration, forced expiration, tidal volume, expiratory reserve volume, inspiratory reserve volume, residual volume, vital capacity, forced expiratory volume, minute respiratory volume, surfactant, and pneumothorax. To describe the role of muscles and volume changes in the mechanics of breathing. To understand that the lungs do not contain muscle and that respirations are therefore caused by external forces. To explore the effect of changing airway resistance on breathing. To understand the effects of hyperventilation, rebreathing, and breath holding on the CO 2 level in the blood.

3. R ESPIRATORY S YSTEM : M ECHANICS Two phases of pulmonary ventilation Inspiration Air is taken into the lungs External intercostal muscles and the diaphragm contract Expiration Air is expelled from the lungs Inspiratory muscles relax,causing the diaphragm to rise and the chest wall to move inward Forced expiration – Ex. blowing up a balloon

4. S IMULATING S PIROMETER : M EASURING R ESPIRATORY V OLUMES AND C APACITIES Normal quiet breathing moves about 500 ml (0.5 liter) of air (the tidal volume) in and out of the lungs with each breath (varies) Normal Respiratory Volumes Tidal volume (TV): Amount of air inhaled or exhaled with each breath under resting conditions (500 ml) Expiratory reserve volume (ERV): Amount of air that can be forcefully exhaled after a normal tidal volume exhalation (1200 ml) Inspiratory reserve volume (IRV): Amount of air that can be forcefully inhaled after a normal tidal volume inhalation (3100 ml) Residual volume (RV): Amount of air remaining in the lungs after complete exhalation (1200 ml) Vital capacity (VC): Maximum amount of air that can be exhaled after a normal maximal inspiration (4800 ml) VC = TV + IRV +ERV Total lung capacity (TLC): Sum of vital capacity and residual volume

5. P ULMONARY F UNCTION T ESTS Forced vital capacity (FVC): Amount of air that can be expelled when the subject takes the deepest possible breath and exhales as completely and rapidly as possible Forced expiratory volume (FEV1): Measures the percentage of the vital capacity that is exhaled during 1 second of the FVC test (normally 75% to 85% of the vital capacity

6. I NSTRUCTIONS 1. Go to Exercise 37B PEx-109 in the back of the Marieb lab manual. 2. Read Pex 109-110 to Activity 1. 3. Insert the PhysioEx CD and select Main Menu, then #7: Respiratory System Mechanics, then Respiratory Volumes from the Experiment drop down menu. 4. Complete Activity 1: Measuring Respiratory Volumes, Steps 1-5 on PEx-110. Answer Question #1 from Activity 1 in the Questions section. For these experiments you can equate radius with diameter. 5. Complete Step 8 from Activity 1 on PEx-112. 6. Answer the remaining questions from Activity 1 in the Questions section.

7. A CTIVITY 1 – M EASURING R ESPIRATORY V OLUMES

8. S IMULATING V ARIATIONS IN B REATHING

9. I NSTRUCTIONS CONT. 7. Complete Activity 2: Examining the Effect of Changing Airway Resistance on Respiratory Volumes, Steps 1-7 on Pex-112. DO NOT Record the FEV 1 or Vital Capacity values in the chart in your lab manual, instead record them in the chart (Question #1) in the Questions section for Activity 2. Also, calculate the FEV 1 (%) by dividing the FEV 1 volume by the Vital Capacity volume and multiplying by 100. Record the FEV 1 (%) in the chart (Question #1) in the Questions section for Activity 2. 8. Answer the remaining questions for Activity 2 in the Questions Section. 9. Read Simulating Variations in Breathing on PEx-115. 10. Select Variations in Breathing from the Experiment drop down menu. 11. Complete Activity 5 (Pex-118): Exploring Various Breathing Patterns, Steps 1-7; Rebreathing, Steps 1 and 2 and Breath Holding, Steps 1-4. Do not answer the questions in your lab manual from this section; instead, answer the questions for Activity 5 in the Questions section.