Chapter 2, VENTILATION: HOW GAS GETS TO THE ALVEOLI Video Solutions, West’s Respiratory Physiology: The Essentials

Problem 1

The only variable in the following list that cannot be measured with a simple spirometer and stopwatch is:
A. Tidal volume
B. Functional residual capacity
C. Vital capacity
D. Total ventilation
E. Respiratory frequency

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02:02

Problem 2

Concerning the pulmonary acinus:
A. Less than $90 \%$ oxygen uptake of the lung occurs in the acini.
B. Percentage change in volume of the acini during inspiration is less than that of the whole lung.
C. Volume of the acini is less than $90 \%$ of the total volume of the lung at FRC.
D. Each acinus is supplied by a terminal bronchiole.
E. The ventilation of the acini at the base of the upright human lung at FRC is less than that at the apex.

Christina Sorrentino

Numerade Educator

02:21

Problem 3

In a measurement of FRC by helium dilution, the original and final helium concentrations were $10 \%$ and $6 \%$, and the spirometer volume was kept at 5 liters. What was the volume of the FRC in liters?
A. 2.5
B. 3.0
C. 3.3
D. 3.8
E. 5.0

Nicholas Majtenyi

Numerade Educator

05:55

Problem 4

A patient sits in a body plethysmograph (body box) and makes an expiratory effort against his closed glottis. What happens to the following: pressure in the lung airways, lung volume, box pressure, box volume?

Ceren Uzun

Texas Tech University

01:07

Problem 4

If $\mathrm{CO}_2$ production remains constant and alveolar ventilation is increased threefold, the alveolar $\mathrm{PCO}_2$ after a steady state is reached will be what percentage of its former value?
A. 25
B. 33
C. 50
D. 100
E. 300

David Collins

Numerade Educator

Problem 6

A 56-year-old woman is started on mechanical ventilation after presenting to the emergency department with acute respiratory failure. The ventilator is set to deliver a tidal volume of 750 mL 10 times per minute. After transfer to the ICU, the physician decreases her tidal volume to 500 mL and raises her respiratory rate to 15 breaths per minute. She is heavily sedated and does not initiate any breaths beyond what the ventilator gives to her (in other words, total ventilation is fixed). Which of the following changes would you expect to occur as a result of the physician's intervention?
A. Decrease in the volume of the anatomic dead space
B. Decrease in airway resistance
C. Decrease in $\mathrm{P}_2 \mathrm{CO}_2$
D. Increase in the dead space fraction
E. Increase in $\mathrm{CO}_2$ production

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Problem 7

A 40-year-old man is receiving mechanical ventilation in the ICU after an admission for severe respiratory failure. The ventilator settings include a tidal volume of 600 ml and respiratory rate of 15 . The patient is in a deep coma and cannot increase his total ventilation beyond what the ventilator is set to deliver. On his fifth hospital day, he develops high fevers and is determined to have a new blood stream infection. Which of the following changes would be expected as a result of this change in the patient's condition?
A. Decrease in the physiologic dead space
B. Decrease in the anatomic dead space
C. Increase in the arterial $\mathrm{PCO}_2$
D. Increase in ventilation to the dependent regions of the lung
E. Increase in the volume of gas delivered to the alveoli with each breath

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