Exercise 7: Respiratory System Mechanics: Activity 1: Measuring Respiratory Volumes and Calculating Capacities Lab
Report
Pre-lab Quiz Results
You scored 100% by answering 5 out of 5 questions correctly.
1. Which of the following statements describing the mechanics of breathing is false?
You correctly answered: d. Ventilation relies exclusively on contracting skeletal muscles.
2. The contraction of which of the following muscles will increase the thoracic cavity volume during inspiration?
You correctly answered: c. the external intercostals
3. At the beginning of inspiration, the
You correctly answered: b. thoracic cavity volume increases.
4. At the beginning of expiration, the
You correctly answered: a. pressure in the thoracic cavity increases.
5. A tidal volume refers to the
You correctly answered: b. amount of air inspired and then expired with each breath under resting conditions
Experiment Results
Predict Question:
Predict Question: Lung diseases are often classified as obstructive or restrictive. An obstructive disease affects airflow,
and a restrictive disease usually reduces volumes and capacities. Although they are not diagnostic, pulmonary function
tests such as forced expiratory volume (FEV1) can help a clinician determine the difference between obstructive and
restrictive diseases. Specifically, an FEV1 is the forced volume expired in 1 second.
In obstructive diseases such as chronic bronchitis and asthma, airway radius is decreased. Thus, FEV1 will
Your answer : a. decrease proportionately.
Stop & Think Questions:
Which muscles contract during quiet expiration?
Your answer : b. abdominal-wall muscles and internal intercostal muscles
Correct answer: d. None of these muscles contract during quiet expiration.
6. Minute ventilation is the amount of air that flows into and then out of the lungs in a minute. Minute ventilation (ml/min) =
TV (ml/breath) x BPM (breaths/min).
Enter the minute ventilation in the field below and then click Submit to record your answer in the lab report.
You answered: 500 ml/min
11. A useful way to express FEV1 is as a percentage of the forced vital capacity (FVC). Using the FEV1 and FVC values
from the data grid, calculate the FEV1 (%) by dividing the FEV1 volume by the FVC volume (in this case, the VC is equal to
the FVC) and multiply by 100%.
Enter the FEV1 (%) for an airway radius of 5.00 mm in the field below and then click Submit to record your answer in the
lab report.
You answered: 74
12. A useful way to express FEV1 is as a percentage of the forced vital capacity (FVC). Using the FEV1 and FVC values
from the data grid, calculate the FEV1 (%) by dividing the FEV1 volume by the FVC volume (in this case, the VC is equal to
the FVC) and multiply by 100%.
Enter the FEV1 (%) for an airway radius of 3.00 mm in the field below and then click Submit to record your answer in the
lab report.
You answered: 70
Post-lab Quiz Results
You scored 60% by answering 3 out of 5 questions correctly.
1. To calculate a person's vital capacity, you need to know the TV, ERV, and
Your answer: b. FEV1.
Correct answer: c. IRV.
2. Measuring a person's FVC means that you are measuring
You correctly answered: d. the amount of air that can be expelled when the subject takes the deepest possible inspiration
and then forcefully expires as completely and rapidly as possible.
3. Measuring a person's FEV1 means that you are measuring
You correctly answered: b. the amount of the VC that is expired during the first second of the FVC test.
4. For a person suffering an asthma attack, inhaler medications are expected to
You correctly answered: a. reduce the airway resistance.
5. Which of the following values does not include the ERV?
Your answer: a. FVC
Correct answer: c. TV
Review Sheet Results
1. What would be an example of an everyday respiratory event the ERV simulates?
Your answer:
The ERV represents a forced expiration(exhale)
Christopher Eberlein
4103825
2. What additional skeletal muscles are utilized in an ERV activity?
Your answer:
Abdominal-wall muscles, internal intercostals, internal/external oblique, transverses abdominis
Christopher Eberlein
4103825
3. What was the FEV1 (%) at the initial radius of 5.00 mm?
Your answer:
74%
Christopher Eberlein
4103825
4. What happened to the FEV1 (%) as the radius of the airways decreased? How well did the results compare with your
prediction?
Your answer:
FEV1 (%) decreased as the airway radius was decreased, just as i had predicted
Christopher Eberlein
4103825
5. Explain why the results from the experiment suggest that there is an obstructive, rather than a restrictive, pulmonary
problem.
Your answer:
The results from the lab show that it is an obstructive airway because the airflow is constantly decreasing, if it was
restrictive the volumes and capacities would have been affected more than what it was.
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