Deck 21: Respiratory Function and Alterations in Gas Exchange

Question 1

The Eustachian tubes travel from the posterior nasopharynx to the inner ear.

Answer 1

False

Question 2

In zone 1 of the lung

A) no air is moving.
B) circulation is highest.
C) venous pressure is high.
D) dead space is high.

Answer 2

dead space is high.

Question 3

Pulmonary artery blood is normally 95% to 100% saturated with oxygen.

Answer 3

False

Question 4

The amount of anatomic dead space is normally about 1 ml per pound of body weight.

Question 5

Restrictive pulmonary disorders are characterized by

A) increased compliance.
B) increased residual volume.
C) decreased respiratory rate.
D) decreased tidal volume.

Question 6

The minute ventilation is calculated by multiplying respiratory rate and tidal volume.

Question 7

An increase in filtration of fluid from the pulmonary capillaries occurs with _____ pressure.

A) increased capillary oncotic
B) increased capillary hydrostatic
C) decreased capillary hydrostatic
D) decreased interstitial oncotic

Question 8

The hypoxemia caused by intrapulmonary shunt can be significantly improved by increasing the fraction of inspired oxygen.

Question 9

Which of the following therapies would be associated with the largest increase in arterial oxygen content in a patient with a PaO₂ of 70 mm Hg and hemoglobin of 10 g/dl?

A) Oxygen administration to increase PaO₂ to 200 mm Hg
B) Bicarbonate administration to raise hemoglobin affinity for oxygen
C) Blood transfusion to raise hemoglobin to 14 g/dl
D) Normal saline administration to raise cardiac output

Question 10

The right mainstem bronchus is straighter than the left.

Question 11

The highest volume of ventilation and perfusion occurs in the upper lung fields.

Question 12

A condition that results in increased pulmonary vascular resistance is

A) anemia.
B) pulmonary hypoxemia.
C) calcium channel-blocking agents.
D) parasympathetic activity.

Question 13

The amount of air remaining in the lungs after a maximal exhalation is called the

A) residual volume.
B) functional residual capacity.
C) expiratory reserve volume.
D) residual capacity.

Question 14

Surfactant is a phospholipid that reduces

A) pulmonary vascular capacitance.
B) elastic recoil force.
C) alveolar surface tension.
D) pulmonary capillary fragility.

Question 15

In zone 3 of the lung

A) dead space is high.
B) alveolar pressure is high.
C) venous pressure is lowest.
D) the greatest blood flow occurs.

Question 16

A structure that participates in diffusion of respiratory gases is the

A) alveolus.
B) bronchiole.
C) trachea.
D) pharynx.

Question 17

Airway resistance to flow is determined primarily by airway diameter.

Question 18

In zone 2 of the lung

A) alveolar volume does not affect blood flow.
B) venous pressure is high.
C) pulmonary vessels are collapsed.
D) blood flow is determined by pulmonary artery and alveolar pressure.

Question 19

The larynx and trachea are part of the upper airway of the respiratory system.

Question 20

Stimulation of $\beta$ ₂ receptors in the bronchioles increases bronchodilation.

Question 21

Intrapulmonary shunting refers to

A) anatomic dead space.
B) alveolar dead space.
C) ventilation without perfusion.
D) perfusion without ventilation.

Question 22

In the lateral decubitus position

A) perfusion is greater in the dependent lung.
B) perfusion is greater in the upper lung.
C) ventilation is greatest at the apex.
D) distribution of ventilation and perfusion are the same as in the upright lung.

Question 23

A patient is placed on 50% oxygen by mask with some relief of her dyspnea. Another arterial blood gas is obtained to evaluate lung function, which shows a PaO₂ of 120 mm Hg. If the previous PaO₂ on room air was 85 mm Hg, has lung function improved from the previous assessment?

A) Yes
B) No

Question 24

Which of the following statements about the oxyhemoglobin dissociation curve is true?

A) Increasing PaO₂ above 90 mm Hg greatly improves saturation.
B) The curve shifts to the left with acidemia.
C) The curve shifts to the right with hypercarbia (increased CO₂).
D) An increase in PaO₂ causes a linear increase in SaO₂.

Question 25

As one moves from the apex of the lung to the dependent areas

A) the alveoli become larger.
B) pleural pressure becomes more negative.
C) compliance becomes greater.
D) alveolar ventilation decreases.

Question 26

Distribution of ventilation in the upright lung is such that

A) the apical portions are better ventilated.
B) the diaphragmatic areas are better ventilated.
C) all areas are ventilated equally.
D) ventilation is not affected by position.

Question 27

The central chemoreceptors for respiratory control are

A) located in the carotid artery.
B) responsive primarily to changes in pH and CO₂.
C) responsive primarily to hypoxemia.
D) deactivated by chronic hypercapnia.

Question 28

The pulmonary vascular system

A) has no $\alpha$ or $\beta$ receptors.
B) has no parasympathetic innervation.
C) responds to norepinephrine with vasoconstriction.
D) has very low compliance.

Question 29

A patient's arterial blood gases show that she has alkalemia (pH = 7.55) owing to hyperventilation. What effect, if any, will alkalemia have on oxygen delivery to tissues?

A) No effect
B) Increased oxygen delivery by increasing PaO₂
C) Decreased oxygen delivery by increasing hemoglobin affinity for O₂
D) Increased oxygen delivery by decreasing hemoglobin affinity for O₂

Question 30

Cardiogenic pulmonary edema results from

A) "leaky" pulmonary capillary membranes.
B) increased pulmonary capillary hydrostatic pressure.
C) exudation of protein-rich fluid into alveoli.
D) inflammatory injury to the capillary basement membrane.

Question 31

A blood gas drawn from a patient's radial artery while she is breathing room air (21% oxygen) shows a PaO₂ of 85 mm Hg. What is the approximate A - aDO₂?

A) 20 mm Hg
B) 64 mm Hg
C) 85 mm Hg
D) 5 mm Hg

Question 32

All of the following contribute to physiologic shunt except

A) bronchial veins.
B) thebesian veins.
C) arteriovenous shunt.
D) nonperfused alveoli.

Question 33

Shifts in the oxyhemoglobin dissociation curve represent the

A) effect of carbonic anhydrase on the uptake of CO₂.
B) ability of blood to pick up more CO₂ when PaO₂ is low.
C) amount of hydrogen in solution in the blood.
D) changes in hemoglobin affinity for oxygen.

Question 34

The peripheral chemoreceptors are

A) located in the medulla oblongata.
B) poorly perfused and have a slow response time.
C) primarily responsible for the hypoxic drive to breathe.
D) unimportant in the adult human.

Question 35

Pamela is a 23-year-old college student who is in good health, lifts weights regularly, and maintains a high-protein, low-fat diet. She is injured in an automobile accident and confined to bed for 4 days in the hospital with a broken leg. On the fifth day of hospitalization, Pamela suddenly becomes very short of breath. She seems unable to get enough air and begins to hyperventilate. A chest x-ray is obtained, but appears normal. Considering the information presented, what is the most likely cause of Pamela's respiratory distress?

A) Sudden onset of asthma
B) Noncardiogenic pulmonary edema
C) Pneumonia
D) Pulmonary embolism

Question 36

Hypoxic pulmonary vasoconstriction

A) diverts blood to nonhypoxic regions.
B) increases blood flow to the base of the lung.
C) is active only at high altitudes.
D) is always detrimental to the patient.

Question 37

To maximize V/Q in a patient with unilateral lung disease, one would

A) ventilate with positive end-expiratory pressure.
B) position with the "good" lung down.
C) administer vasodilating agents.
D) position with the diseased lung dependent.

Question 38

Most of the carbon dioxide in blood is transported

A) as bicarbonate.
B) in physical solution.
C) as carbonic acid.
D) as carbaminohemoglobin.