Deck 13: The Respiratory System

Question 1

During which of the following would the intrapleural pressure be greater than atmospheric pressure?

A)forced inspiration
B)passive expiration
C)passive inspiration
D)pneumothorax
E)None of the above

Answer 1

E

Question 2

Which statement is incorrect?

A)Alveoli are the site of gas exchange in the lungs.
B)Pores of Kohn allow air to flow between adjacent bronchioles.
C)Alveolar Type II cells secrete pulmonary surfactant.
D)Alveoli are very thin and are surrounded by a network of capillaries so that air and blood are separated by a very thin barrier.
E)The alveoli are thin-walled, inflatable, grape-like sacs at the end of the bronchioles.

Answer 2

B

Question 3

Which of the following is not a function of the respiratory system?

A)transports O₂ to the tissues
B)contributes to maintenance of normal acid-base balance
C)provides a route for heat and water elimination
D)enables speech, singing, and other vocalization
E)removes, modifies, activates, or inactivates various materials passing through the pulmonary circulation

Answer 3

A

Question 4

Airway resistance

A)is normally the primary factor determining the amount of flow into/out of the lungs
B)decreases when the diameter of the airways becomes reduced
C)when elevated, requires an increased pressure gradient between the lungs and atmosphere through vigorous respiratory efforts to move even normal volumes of air into and out of the lungs
D)is lower in people with asthma
E)decreases when lung compliance increases

Question 5

The intrapulmonary pressure

A)is the pressure within the air sacs of the lung
B)always equilibrates with atmospheric pressure
C)is always less than intrapleural pressure
D)is both a and b
E)is both a and c

Question 6

Type I alveolar cells

A)form the wall of the alveoli
B)secrete pulmonary surfactant
C)contract during expiration to force air out of the alveoli
D)have characteristics a and c
E)have all of the above characteristics

Question 7

A transmural pressure gradient exists across the lung wall because the ____ pressure is less than the ____ pressure.

A)intrapleural; intra-alveolar
B)intra-alveolar; intrapleural
C)intrapleural; atmospheric
D)atmospheric; intra-alveolar
E)atmospheric; intrapleural

Question 8

In addition to gas exchange, the respiratory system plays a key role in

A)enhancing venous return
B)water and temperature balance
C)body defense
D)enhancing venous return and body defense
E)all of the above

Question 9

When the diaphragm contracts,

A)the volume of the thoracic cavity increases
B)lung volume increases as the lungs are forced to expand
C)the intra-alveolar pressure increases
D)both a and b occur
E)a, b, and c occur

Question 10

Which of the following is the last step that produces an inspiration?

A)The atmospheric pressure becomes lower than the intrapleural pressure.
B)The diaphragm contracts.
C)The intercostal muscles contract.
D)The intra-alveolar pressure becomes lower than the atmospheric pressure.
E)The intrapleural pressure becomes positive.

Question 11

The respiratory quotient is

A)the rate at which gases diffuse across the alveolar capillary membrane
B)respiratory rate times tidal volume
C)the ratio of O₂ consumed to CO₂ produced
D)the ratio of CO₂ produced to O₂ consumed
E)equal to 1.0 on a typical American diet

Question 12

During inspiration,

A)intra-alveolar pressure falls below atmospheric pressure.
B)the diaphragm contracts.
C)the internal intercostal muscles contract.
D)conditions a and b exist
E)conditions a, b, and c exist

Question 13

Under normal conditions, when _______ pressure becomes greater than _______ pressure, air will flow out of the lungs.

A)intra-alveolar, atmospheric
B)intra-alveolar, intrapleural
C)intrapleural, intra-alveolar
D)intrapleural, atmospheric
E)atmospheric, intra-alveolar

Question 14

Inspiratory events occur because

A)the air pressure in the alveoli is greater than that of the atmosphere
B)the air pressure in the alveoli is less than that of the atmosphere
C)the volume of the thoracic cavity increases
D)of conditions a and b
E)of conditions b and c

Question 15

The inspiratory muscles include the

A)diaphragm and internal intercostal muscles
B)diaphragm and external intercostal muscles
C)diaphragm and abdominal muscles
D)internal and external intercostal muscles
E)intercostal and abdominal muscles

Question 16

At the end of a normal expiration, when outward air flow has ceased,

A)Intra-alveolar pressure is less than atmospheric pressure.
B)Intra-alveolar pressure is greater than atmospheric pressure.
C)Intra-alveolar pressure is equal to atmospheric pressure.
D)Intrapleural pressure is greater than atmospheric pressure.
E)Intrapleural pressure is greater than intra-alveolar pressure.

Question 17

Which activity below is not a respiratory event?

A)Carbon dioxide is exchanged in the alveoli.
B)Cells produce nitrogen by their metabolism.
C)Gas exchange between tissues and the blood.
D)Oxygen is exchanged in the alveoli.
E)Pulmonary ventilation.

Question 18

Which of the following structures serves as a common passageway for both the respiratory and digestive systems?

A)nose
B)pharynx
C)trachea
D)bronchi
E)esophagus

Question 19

The lungs are held against the thoracic wall due to

A)the negative intrapleural pressure
B)the positive intrapulmonary pressure
C)cohesiveness of the pleural fluids
D)all of the above
E)only a and c

Question 20

The entire sequence of events involved in the exchange of O₂ and CO₂ between the body cells and the surrounding environment is known as

A)internal respiration
B)external respiration
C)ventilation
D)breathing
E)ventilation and breathing

Question 21

Which of the following statements concerning pulmonary surfactant is incorrect?

A)It is secreted by Type II alveolar cells.
B)It is deficient in newborn respiratory distress syndrome.
C)It promotes elastic recoil of the lungs.
D)It reduces the cohesive force between water molecules.
E)It reduces surface tension.

Question 22

Which of the following is incorrect if blood flow to an area of the lungs is reduced while airflow remains normal?

A)The concentration of CO₂ in this area decreases.
B)The change in CO₂ concentration causes smooth muscles of the local airways to relax.
C)The change in CO₂ concentration leads to increased resistance of local airways.
D)The change in O₂ concentration leads to dilation of local blood vessels.
E)The change in O₂ concentration leads to decreased vascular resistance.

Question 23

Which of the following promotes elastic recoil of the lungs?

A)Elastic fibers in the lung
B)Surface tension of the fluid lining the alveoli
C)Pulmonary surfactant
D)Both a and b
E)All of the above

Question 24

Bronchodilation of the air passages involves the ____ of their smooth muscle and the ____ of their radius.

A)decrease; decrease
B)decrease; increase
C)increase; decrease
D)increase; increase
E)None of the above

Question 25

Which of the following does not bring about increased airway resistance?

A)asthma
B)epinephrine
C)slow-reactive substance of anaphylaxis
D)emphysema
E)excess mucus production

Question 26

Which type of chronic obstructive pulmonary disease is characterized by a breakdown of alveolar walls and collapse of the smaller airways?

A)asthma
B)chronic bronchitis
C)emphysema
D)All of the above
E)Only b and c

Question 27

The work of breathing normally requires about 3% of total energy expenditure; this increases under all of the following situations except when

A)elastic recoil decreases
B)resistance increases
C)the partial pressure of oxygen increases in the air
D)ventilation increases
E)compliance decreases

Question 28

When the level of blood flow is not ideally matched with the amount of airflow in a localized area of lung tissue,

A)autoregulatory mechanisms are invoked
B)the autonomic nervous system couples the events more ideally
C)and if airflow is low and blood flow too high, arteriolar vasoconstriction occurs
D)both a and b occur
E)both a and c occur

Question 29

Which of the following is/are innervated by the phrenic nerve?

A)abdominal muscles
B)diaphragm
C)external intercostal muscles
D)internal intercostal muscles
E)accessory inspiratory muscles

Question 30

The minimum volume of air that remains in the lungs after a maximal expiration is termed the

A)tidal volume
B)functional residual capacity
C)residual volume
D)vital capacity
E)None of the above

Question 31

The residual volume is

A)important in helping prevent lung collapse
B)the normal volume of air inhaled
C)the normal volume of air exhaled
D)the maximum volume of air that can be inspired
E)the minimum volume of air that can be inspired

Question 32

Which of the following makes breathing more difficult?

A)Increased pulmonary compliance
B)Increased airway resistance
C)Decreased elastic recoil
D)both a and c
E)both b and c

Question 33

The vital capacity is

A)the volume normally entering or leaving the lungs during a single breath
B)the difference in volume between maximum inspiration and maximum exhalation
C)the maximum volume the lungs can hold
D)the minimum volume the lungs can hold
E)none of these

Question 34

Which factor would result in bronchoconstriction?

A)sympathetic stimulation
B)parasympathetic stimulation
C)epinephrine secretion
D)increased carbon dioxide concentration
E)None of the above

Question 35

Without pulmonary surfactant,

A)small alveoli would tend to collapse
B)larger alveoli would tend to empty into smaller alveoli
C)all alveoli would be easier to inflate
D)the surface tension in the alveoli would be reduced
E)inspiration would be easier

Question 36

During forceful expiration,

A)accessory expiratory muscles contract
B)internal intercostals contract
C)abdominal muscles contract
D)ribs are brought closer together
E)all of the above occur

Question 37

Which of the following would not be expected for a patient suffering from obstructive lung disease?

A)normal total lung capacity
B)increased functional residual capacity
C)decreased residual volume
D)decreased FEV1
E)None of the above would be affected

Question 38

Which of the following does not occur during expiration when a person is breathing quietly?

A)The size of the thoracic cavity is reduced.
B)The intra-alveolar pressure becomes greater than atmospheric pressure.
C)Air flows out of the lungs.
D)The expiratory muscles contract.
E)Intrapleural pressure remains less than intra-alveolar pressure.

Question 39

Pulmonary surfactant

A)is secreted by Type II alveolar cells
B)decreases surface tension of the fluid lining the alveoli
C)resists elastic recoil of the lungs
D)is a combination of lipids and proteins
E)has all of the above characteristics

Question 40

Normal expiration is brought on by

A)contraction of the external intercostals
B)contraction of the internal intercostals
C)contraction of the diaphragm
D)elastic recoil of inspiratory muscles
E)elastic recoil of expiratory muscles

Question 41

If the alveolar is 100 mm Hg, the blood leaving the pulmonary capillaries in a normal person will have a of

A)40 mm Hg
B)46 mm Hg
C)100 mm Hg
D)760 mm Hg
E)none of these

Question 42

A person who has a tidal volume of 400 ml/breath, a respiratory rate of 14 breaths/minute, and an anatomic dead space volume of 120 ml will have a pulmonary ventilation rate of

A)3000 ml/minute
B)3920 ml/minute
C)4260 ml/minute
D)5600 ml/minute
E)6240 ml/minute

Question 43

Systemic venous is ____ alveolar
, and systemic venous
Is ____ alveolar .

A)greater than, greater than
B)greater than, less than
C)less than, greater than
D)less than, less than
E)equal to, equal to

Question 44

All of the following would result in lower oxygen saturation of hemoglobin except

A)an increase in
B)an increase in temperature
C)an increase in
D)a decrease in pH
E)an increase in DPG

Question 45

Which of the following forces does not contribute to keeping the alveoli open?

A)alveolar surface tension
B)transmural pressure gradient
C)pulmonary surfactant
D)Movement of air between alveoli through pores of Kohn
E)None of the above contribute to keeping the alveoli open.

Question 46

If the pulmonary ventilation rate is 3200 ml/minute with a tidal volume of 400, the respiratory rate is ____ breaths per minute.

A)6
B)8
C)14
D)16
E)20

Question 47

Compliance refers specifically to the

A)effort required to stretch the lungs
B)elasticity of the lung tissue
C)energy requirements for an inspiration
D)surface area of the alveoli
E)volume of air moved per breathing cycle

Question 48

Hemoglobin

A)plays a critical role in determining the total amount of O₂ that is exchanged in the lungs because it removes O₂ and keeps the low so that net diffusion continues
B)combines only with O₂
C)is found in erythrocytes
D)does both a and c
E)does none of the above

Question 49

Which condition would result in the lowest alveolar ventilation rate?

A)quiet breathing
B)a normal respiratory rate and normal tidal volume
C)a low respiratory rate and high tidal volume
D)a high respiratory rate and very low tidal volume
E)a low respiratory rate and very low tidal volume

Question 50

Which factor would reduce the alveolar ventilation rate the most?

A)increased alveolar dead space
B)decreased alveolar dead space
C)increased respiratory rate
D)increased tidal volume
E)quiet breathing

Question 51

Which of the following would decrease diffusion of a gas across the alveolar/pulmonary capillary membrane?

A)An increase in thickness of the membrane
B)An increase in surface area of the membrane
C)An increase in the partial pressure gradient
D)a and c only
E)a, b, and c

Question 52

If 20% of the air is composed of O₂, the partial pressure of oxygen at sea level where atmospheric pressure is 760 mm Hg is

A)20 mm Hg
B)760 mm Hg
C)70 mm Hg
D)350 mm Hg
E)152 mm Hg

Question 53

in the blood is

A)the pressure exerted by the amount of oxygen dissolved in the blood
B)the most important factor determining the percent saturation of hemoglobin
C)normal in carbon monoxide poisoning
D)only a and b
E)a, b, and c

Question 54

If 20% of the air is composed of O₂, the partial pressure of oxygen at an altitude of 20,000 feet where atmospheric pressure is 350 mm Hg is

A)20 mm Hg
B)760 mm Hg
C)70 mm Hg
D)350 mm Hg
E)152 mm Hg

Question 55

Intrapleural pressure exceeds airway pressure

A)during normal quiet breathing
B)during maximal forced expiration
C)in response to a pneumothorax
D)during maximal forced expiration and in response to a pneumothorax
E)in all of the above situations

Question 56

The partial pressure of oxygen in the pulmonary veins is

A)about 40 mmHg
B)equivalent to alveolar partial pressure
C)dramatically different than pulmonary arteries partial pressure
D)equivalent to the partial pressure of oxygen in the arteriolar ends of systemic capillaries
E)all of the above

Question 57

The percent of hemoglobin saturation decreases as

A) increases
B) increases
C)H+ decreases
D)body temperature decreases
E)blood pH decreases

Question 58

Which factor would reduce the amount of oxygen transfer across the respiratory membrane?

A)a higher partial pressure of oxygen in the atmosphere
B)an abnormally high partial pressure of carbon dioxide in the atmosphere
C)a reduced partial pressure of carbon dioxide in the atmosphere
D)a low pulmonary capillary partial pressure of oxygen
E)None of the above

Question 59

A person who has a tidal volume of 400 ml, a respiratory rate of 14, and an anatomic dead space volume of 150 ml will have an alveolar ventilation rate of

A)3,500 ml/minute
B)3,920 ml/minute
C)4,260 ml/minute
D)5,600 ml/minute
E)6,240 ml/minute

Question 60

The partial pressure of oxygen

A)in the atmospheric air averages 79 percent of total atmospheric pressure
B)in blood is the most important factor that determines percent O₂ saturation of Hb
C)in arterial blood decreases when Hb preferentially combines with CO rather than O₂
D)is both b and c
E)is none of the above

Question 61

The plateau portion of the O?-Hb curve

A)is in the blood- $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ range that exists at pulmonary capillaries
B)means that Hb becomes nearly saturated in the lungs unless pulmonary capillary $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ falls below 60 mm Hg
C)is in the blood- $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ range that exists at the systemic capillaries
D)is both a and b
E)is both b and c

Question 62

The atmospheric $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ is approximately

A)25 mm Hg
B)120 mm Hg
C)160 mm Hg
D)220 mm Hg
E)the same as for nitrogen

Question 63

The chloride shift in red blood cells

A)causes the development of an electrical gradient
B)occurs in response to bicarbonate movement into the plasma
C)causes a decrease in blood pH
D)involves the exchange of H+ for Cl- ions on hemoglobin molecules
E)involves the exchange of HCO3- for Cl- ions on hemoglobin

Question 64

Carbon dioxide is transported in the blood in all the following ways except

A)bicarbonate ion
B)carbonic acid
C)directly dissolved
D)bound to heme
E)bound to globin

Question 65

Which condition exists at high altitudes?

A)histotoxic hypoxia
B)hypoxic hypoxia
C)anemic hypoxia
D)hypocapnia
E)None of the above

Question 66

Select the incorrect statement about hemoglobin.

A)It combines with oxygen at the lungs.
B)It contains iron.
C)It forms an irreversible association with oxygen.
D)It is located inside the red blood cell.
E)Its globin portion is a polypeptide.

Question 67

Approximately what percentage of oxygen is transported in the blood dissolved in free form?

A)1.5
B)15
C)60
D)72
E)100

Question 68

Hemoglobin has the greatest affinity for

A)carbon dioxide
B)oxygen
C)carbon monoxide
D)nitrogen
E)sulfur dioxide

Question 69

The amount of oxygen unloaded from Hb at the tissue level increases when

A) $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ in the tissue increases
B)the concentration of DPG in the red blood cells increases
C)the concentration of CO? in the red blood cells decreases
D)a and b occur
E)a and c occur

Question 70

The stretch receptors for the Hering-Breuer reflex are located in the

A)diaphragm
B)elastic tissue of the lungs
C)medulla
D)smooth muscle of the airways
E)trachea

Question 71

Hypercapnia

A)refers to excess CO₂ in the arterial blood
B)occurs when CO₂ is blown off to the atmosphere at a rate faster than it is being produced by the tissues
C)may be caused by hypoventilation
D)would likely result in a higher percent saturation of oxygen on Hb
E)would tend to raise the blood's pH

Question 72

Identify the correct statement(s).

A)The DRG consists of both inspiratory neurons and expiratory neurons.
B)The neurons of the DRG remain inactive during normal quiet breathing.
C)The DRG is called into play by the VRG as when demands for ventilation are increased.
D)All of the above are correct.
E)None of the above are correct.

Question 73

Hemoglobin

A)combines preferentially with O₂ over any other substance
B)is known as carboxyhemoglobin when combined with carbon dioxide
C)plays a critical role in determining the amount of O₂ exchanged between alveoli and blood
D)has characteristics a and c
E)has all of the above characteristics

Question 74

What is the primary form in which CO₂ is transported in the blood?

A)physically dissolved
B)bound to hemoglobin
C)bound to plasma protein
D)as bicarbonate
E)as carbonic anhydrase

Question 75

Approximately what percent of carbon dioxide is transported in the blood dissolved in dissolved form?

A)1.5
B)10
C)35
D)60
E)100

Question 76

Carbonic anhydrase

A)is found in the red blood cells
B)catalyzes the formation of carbonic acid from carbonic dioxide and water
C)catalyzes the formation of oxyhemoglobin from oxygen and reduced hemoglobin
D)has characteristics a and b
E)has characteristics b and c

Question 77

The inspiratory neurons

A)activate the phrenic nerve, bringing about contraction of the diaphragm
B)are stimulated by stretch receptors
C)are inhibited by the DRG when the DRG is stimulated by the apneustic area
D)have characteristics a and c
E)have characteristics b and c

Question 78

The brain region that provides output to the respiratory muscles is located in the

A)pons
B)medulla
C)cerebral cortex
D)cerebellum
E)hypothalamus

Question 79

Identify the correct statement(s).

A)The presence of Hb keeps blood $\mathrm { P } _ { \mathrm { O } _ { 2 } }$ low and favors O? movement into the blood.
B)Hb can combine with O?, CO?, H+, and CO.
C)Hb unloads more O? in the presence of increased tissue acidity.
D)Hb buffers against changes in pH due to respiratory carbonic acid.
E)All of the statements are true.

Question 80

Pacemaker activity that establishes the rhythmicity of breathing resides in the

A)lung tissue
B)respiratory muscles
C)dorsal respiratory group
D)phrenic nerve
E)cerebrum