1. According to the results obtained, the experimental VC is lower than the predicted VC value. The experimental values for VC, FRC and TLC are substantially lower than the predicted values which are based on heights and ages. The differences in the results could possibly be because to the person has a smaller chest cavity, a lower level of fitness or a habit of smoking which decreases FRC. Psychological effects such as self-consciousness of the person could have also caused the differences in the values. The structure of the equipment, having a long connection tube also adds on to the dead space hence increasing the level of CO2 over time, which can alter the results.

2. As shown in our results, the time period between the expiration peaks in flow pattern is shorter than the inspiration peaks. This shows that exhalation is a passive action because it does not require effort, therefore air flows out faster and expiration occurs over a shorter time compared to inspiration. During inspiration, muscular effort is needed and the pattern of the flow shows that period of inspiration is longer than expiration.

3. RV cannot be determined by ordinary spirometry because it is physically not possible to exhale the RV. The RV is there because during inspiration a lower pressure is created in out lungs. If the RV is not present, our lungs would collapse. While spirometry cannot determine this, special techniques have been made to determine this, such as nitrogen washout.

4. The experimental values are significantly lower than the predicted values. This could because to the person having weak lung muscles because of regular smoking. It may also be because the person has asthma, or has a lower fitness level.

5. The ratio tells us the maximum amount of air that can be forcefully pushed out by the lungs and how efficient the lungs are at exhaling forcefully as quickly as possible. This procedure is helpful in showing any possible obstructive lung disease that the person has like asthma or bronchitis.

6. The results for forced breathing were more or less consistent for all three trials.

7. The forced expiratory volume in 1 second (FEV1) is decreased, the forced vital capacity (FVC) is normal and the ratio FEV1/FVC decreased. The total volume of air expired after full inspiration (FVC) is slightly decreased. This may be because of incomplete emptying of the lungs. The volume of air expired in the first second during maximal expiratory effort (FEV1) decreased dramatically because of increased airway resistance. The percentage of the vital capacity which is expired in the first second of maximal expiration (FEV1/FVC) decreased as a result of FEV1 decreasing.

8. The physiological events encountered by a person having an asthma attack are:
• Bronchoconstriction: The muscles outside of the bronchial tubes contract which causes narrowing. This makes it increasingly more difficult to move air through the lungs. At this stage, the person experiences symptoms such as shortness of breath, chest tightening and wheezing.
• Mucus production: Airways of the lung produce an increased amount of mucus which may result in mucus plugging and narrowing of the airways.
• Inflammation: The inside of the airways become inflamed and swollen, which decreases airflow even more, making it more difficult for the person to breath
In addition to this, the person may feel nervousness and panic which can further worsen symptoms.
9. The FVC values range from 36% to 96%. While volunteer 3’s FVC value remained fairly normal, the FEV1 value was low relative to the other volunteers which then caused the FEV1/FVC ratio value to decrease substantially below normal. Volunteer’s 1 PIF and PEF is considerably higher than the remaining three volunteers. This may be because she had more time to become accustomed to the equipment. Another possibility is that there was an experimental error that occurred during the experiment causing the results to be altered. This could have been because the mouthpiece was not put on properly or the volunteer was not doing what was instructed to the best of his/her ability.

10. Differences in health and fitness of the individual would have had an effect on pulmonary parameters because of smoking and the individuals genetics. Also, factors such as the person’s gender, age, height and weight would contribute to the differences in results. It is also important to remember that experimental error may also alter the results obtained.