The part of the respiratory unit where the gas exchange first begins are the:

1. Atrium
2. Alveolar ducts
3. Alveolar sacs
4. Respiratory bronchioles

A person has a normal exhalation. Which of the following would be true at the end of this effort?

1. The pressure of the intrapleural cavity is the same as atmospheric pressure

2. The alveolar pressure is less than atmospheric pressure

3. The tendency for the lungs to recoil to an unstretched state is balanced by the tendency of the chest wall to expand

4. Alveolar pressure minus intrapleural pressure is zero

A condition in which a person's airways become inflamed, narrow, swell and produce extra mucus, which makes it difficult to breathe is known as

Given are the results of a pulmonary function test of a normal healthy male:
A. A resting tidal volume of 500 ml.
B. An anatomic dead space of 150 ml.
C. Breathing rate of 10 breaths/minute.
D. A total lung capacity of 6000ml.
E. A residual volume of 1000ml.

Which of the following statements is correct?

1. His alveolar ventilation would be 6.5 L/minute
2. Doubling the breathing rate would double his alveolar ventilation
3. Doubling the depth of respiration (tidal volume would double his alveolar ventilation)
4. His vital capacity is 5500ml

The total volume of the conducting airways from the nose or mouth down to the level of the terminal bronchioles [about 150ml] which is not capable of exchanging gases with the blood, is referred to as
1. Physiological dead space
2. Anatomical dead space
3. Alveolar dead space
4. Respiratory zone dead space

During the passage of blood through a tissue with normal metabolism, the percentage of hemoglobin that unloads oxygen is approximately:

Which of the following is applicable to a change in the affinity of hemoglobin for oxygen?
1. Decreased in rapidly metabolizing tissues
2. Increased at higher than normal body temperatures
3. Increased at higher than normal blood 2,3-DPG levels
4. Decreased at more basic than normal blood pH

What is the number of lobes in the right and the left lungs respectively?

During expiration, the diaphragm and external intercostal muscles are:

1. contracted

2. relaxed

3. flexed

4. both relaxed (diaphragm) and flexed (intercostal muscles)

The respiratory center in humans can be primarily stimulated by:
1. carbon dioxide and hydrogen ions
2. oxygen gas levels in the blood
3. oxygen gas levels in the hemoglobin
4. conscious feeling for the need for more oxygen