Deck 22: The Respiratory System

Question 1

Select the correct statement about the neural mechanisms of respiratory control.

A) The pontine respirator group (PRG) continuously stimulates the medulla to provide inspiratory drive.
B) The pons is thought to be instrumental in the smooth transition from inspiration to expiration.
C) The dorsal respiratory group neurons depolarize in a rhythmic way to establish the pattern of breathing.
D) The ventral respiratory group is contained within the pons.

Answer 1

B

Question 2

The major nonelastic source of resistance to air flow in the respiratory passageways is .

A) air pressure
B) surfactant
C) friction
D) surface tension

Answer 2

C

Question 3

The amount of air that can be inspired above the tidal volume is called _.

A) reserve air
B) inspiratory reserve
C) expiratory capacity
D) vital capacity

Answer 3

B

Question 4

Tidal volume is air .

A) remaining in the lungs after forced expiration
B) exchanged during normal breathing
C) forcibly expelled after normal expiration
D) inhaled after normal inspiration

Question 5

A premature baby usually has difficulty breathing. However, the respiratory system is developed enough for survival by _.

A) 28 weeks
B) 17 weeks
C) 24 weeks
D) 36 weeks

Question 6

The lung volume that represents the total volume of exchangeable air is the .

A) tidal volume
B) vital capacity
C) expiratory reserve volume
D) inspiratory capacity

Question 7

Most inspired particles such as dust fail to reach the lungs because of the _ .

A) ciliated mucous lining in the nose
B) abundant blood supply to nasal mucosa
C) action of the epiglottis
D) porous structure of turbinate bones

Question 8

Which of the choices below is not a factor that promotes oxygen binding to and dissociation from hemoglobin?

A) partial pressure of carbon dioxide
B) temperature
C) partial pressure of oxygen
D) number of red blood cells

Question 9

The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to .

A) replace mucus in the alveoli
B) trap dust and other debris
C) protect the lungs from bacterial invasion
D) secrete surfactant

Question 10

Select the correct statement about the physical factors influencing pulmonary ventilation.

A) A decrease in compliance causes an increase in ventilation.
B) As alveolar surface tension increases, additional muscle action will be required.
C) A lung that is less elastic will require less muscle action to perform adequate ventilation.
D) Surfactant helps increase alveolar surface tension.

Question 11

In the plasma, the quantity of oxygen in solution is .

A) not present except where it is combined with carrier molecules
B) greater than the oxygen combined with hemoglobin
C) about equal to the oxygen combined with hemoglobin
D) only about 1.5% of the oxygen carried in blood

Question 12

Which of the following incorrectly describes mechanisms of CO₂ transport?

A) 7- 10% of CO₂ is dissolved directly into the plasma
B) attached to the heme part of hemoglobin
C) as bicarbonate ion in plasma
D) 20% of CO₂ is carried in the form of carbaminohemoglobin

Question 13

Which of the following is not possible?

A) The amount of gas flowing in and out of the alveoli is directly proportional to the difference in pressure or pressure gradient between the external atmosphere and the alveoli.
B) Pressure gradient equals gas flow over resistance.
C) Resistance equals pressure gradient over gas flow.
D) Gas flow equals pressure gradient over resistance.

Question 14

The main site of gas exchange is the .

A) respiratory bronchiole
B) alveolar duct
C) alveolar sacs
D) alveoli

Question 15

Which statement about CO₂ is incorrect?

A) Its accumulation in the blood is associated with a decrease in pH.
B) Its concentration in the blood is decreased by hyperventilation.
C) CO₂ concentrations are greater in venous blood than arterial blood.
D) More CO₂ dissolves in the blood plasma than is carried in the RBCs.

Question 16

Unlike inspiration, expiration is a passive act because no muscular contractions are involved. Expiration, however, depends on two factors. Which of the choices below lists those two factors?

A) the expansion of respiratory muscles that were contracted during inspiration and the lack of surface tension on the alveolar wall
B) the negative feedback of expansion fibers used during inspiration and the outward pull of surface tension due to surfactant
C) combined amount of CO₂ in the blood and air in the alveoli
D) the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

Question 17

The most powerful respiratory stimulus for breathing in a healthy person is .

A) acidosis
B) alkalosis
C) loss of oxygen in tissues
D) increase of carbon dioxide

Question 18

The respiratory membrane is a combination of _.

A) atria and alveolar sacs
B) respiratory bronchioles and alveolar ducts
C) alveolar and capillary walls and their fused basement membranes
D) respiratory bronchioles and alveolar sacs

Question 19

The loudness of a person's voice depends on the .

A) strength of the intrinsic laryngeal muscles
B) thickness of vestibular folds
C) force with which air rushes across the vocal folds
D) length of the vocal folds

Question 20

For gas exchange to be efficient, the respiratory membrane must be .

A) 0.5 to 1 micrometer thick
B) between 5 and 6 micrometers thick
C) The thickness of the respiratory membrane is not important in the efficiency of gas exchange.
D) at least 3 micrometers thick

Question 21

Which of the following is not a form of lung cancer?

A) squamous cell carcinoma
B) small cell carcinoma
C) adenocarcinoma
D) Kaposi's sarcoma

Question 22

Respiratory control centers are located in the .

A) midbrain and medulla
B) pons and midbrain
C) upper spinal cord and medulla
D) medulla and pons

Question 23

Which of the following is not a stimulus for breathing?

A) arterial PO₂ below 60 mm Hg
B) acidosis resulting from CO₂ retention
C) rising carbon dioxide levels
D) rising blood pressure

Question 24

The erythrocyte count increases after a while when an individual goes from a low to a high altitude because the .

A) temperature is lower at higher altitudes
B) concentration of oxygen and/or total atmospheric pressure is lower at high altitudes
C) concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes
D) basal metabolic rate is higher at high altitudes

Question 25

Which respiratory- associated muscles would contract if you were to blow up a balloon?

A) internal intercostals and abdominal muscles would contract
B) external intercostals would contract and diaphragm would relax
C) diaphragm would contract, external intercostals would relax
D) diaphragm contracts, internal intercostals would relax

Question 26

Which of the choices below is not a role of the pleura?

A) allows the lungs to inflate and deflate without friction
B) helps limit the spread of local infections
C) aids in blood flow to and from the heart because the heart sits between the lungs
D) helps divide the thoracic cavity into three chambers

Question 27

Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by
)

A) diffusion
B) filtration
C) active transport
D) osmosis

Question 28

Gas emboli may occur because a .

A) person breathes pure oxygen in a pressurized chamber
B) pilot holds her breath upon descent
C) diver holds his breath upon ascent
D) person holds his breath too long

Question 29

Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs?

A) compliance and the surface tension of the alveolar fluid
B) compliance and transpulmonary pressures
C) the natural tendency for the lungs to recoil and transpulmonary pressures
D) the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid

Question 30

The nose serves all the following functions except .

A) as the direct initiator of the cough reflex
B) warming and humidifying the air
C) cleansing the air
D) as a passageway for air movement

Question 31

Which of the following maintains the patency (openness) of the trachea?

A) pseudostratified ciliated epithelium
B) C- shaped cartilage rings
C) surfactant production
D) surface tension of water

Question 32

Which of the following counteracts the movement of bicarbonate ions from the RBC?

A) the Haldane effect
B) release of hydrogen ion
C) chloride shifting
D) the Bohr effect

Question 33

Inspiratory capacity is .

A) the total amount of exchangeable air
B) the total amount of air that can be inspired after a tidal expiration
C) functional residual capacity
D) air inspired after a tidal inhalation

Question 34

Which of the following does not influence hemoglobin saturation?

A) BPG
B) temperature
C) carbon dioxide
D) nitric oxide

Question 35

Possible causes of hypoxia include _.

A) getting very cold
B) obstruction of the esophagus
C) too little oxygen in the atmosphere
D) taking several rapid deep breaths

Question 36

Which center is located in the pons?

A) pacemaker neuron center
B) expiratory center
C) inspiratory center
D) pontine respirator group (PRG)

Question 37

Which of the following statements is true regarding the respiratory rate of a newborn?

A) The respiratory rate of a newborn is approximately 30 respirations per minute.
B) The respiratory rate of a newborn is, at its highest rate, approximately 40- 80 respirations per minute.
C) The respiratory rate of a newborn varies between male and female infants.
D) The respiratory rate of a newborn is slow.

Question 38

The relationship between gas pressure and gas volume is described by .

A) Dalton's law
B) Boyle's law
C) Charles' law
D) Henry's law

Question 39

Which of the following is not an event necessary to supply the body with O₂ and dispose of CO₂?

A) external respiration
B) blood pH adjustment
C) internal respiration
D) pulmonary ventilation

Question 40

Because the lungs are filled with fluid during fetal life, which of the following statements is true regarding respiratory exchange?

A) Respiratory exchanges are not necessary.
B) Respiratory exchanges are made through the placenta.
C) Because the lungs develop later in gestation, fetuses do not need a mechanism for respiratory exchange.
D) Respiratory exchanges are made through the ductus arteriosus.

Question 41

How is the bulk of carbon dioxide carried in blood?

A) as carbonic acid in the plasma
B) chemically combined with the heme portion of hemoglobin
C) as the bicarbonate ion in the plasma after first entering the red blood cells
D) chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells

Question 42

The larynx contains _.

A) a cricoid cartilage also called the Adam's apple
B) lateral cartilage ridges called false vocal folds
C) the thyroid cartilage
D) an upper pair of avascular mucosal folds called true vocal folds

Question 43

Figure 22.1Using Figure 22.1, match the following:
Larynx.

Question 44

Select the correct statement about the pharynx.

A) The palatine tonsils are embedded in the lateral walls of the nasopharynx.
B) The auditory tube drains into the nasopharynx.
C) The pharyngeal tonsil is located in the laryngopharynx.
D) The laryngopharynx blends posteriorly into the nasopharynx.

Question 45

Which of the following statements is incorrect?

A) The chest wall becomes more rigid with age.
B) During fetal life, lungs are filled with fluid.
C) Respiratory rate is lowest in newborn infants.
D) Descent of the diaphragm results in abdominal breathing.

Question 46

Surfactant helps to prevent the alveoli from collapsing by .

A) warming the air before it enters
B) humidifying the air before it enters
C) interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid
D) protecting the surface of alveoli from dehydration and other environmental variations

Question 47

With the Bohr effect, more oxygen is released because a(n) .

A) increase in pH (alkalosis) strengthens the hemoglobin- oxygen bond
B) decrease in pH (acidosis) strengthens the hemoglobin- oxygen bond
C) increase in pH (alkalosis) weakens the hemoglobin- oxygen bond
D) decrease in pH (acidosis) weakens the hemoglobin- oxygen bond

Question 48

Complete the following statement using the choices below. Air moves out of the lungs when the pressure inside the lungs is .

A) greater than the intra- alveolar pressure
B) equal to the pressure in the atmosphere
C) less than the pressure in the atmosphere
D) greater than the pressure in the atmosphere

Question 49

Which of the choices below determines the direction of respiratory gas movement?

A) solubility in water
B) partial pressure gradient
C) molecular weight and size of the gas molecule
D) the temperature

Question 50

Which of the following provide the greatest surface area for gas exchange?

A) alveolar ducts
B) alveolar sacs
C) respiratory bronchioles
D) alveoli

Question 51

Which of the following determines lung compliance?

A) airway opening
B) alveolar surface tension
C) flexibility of the thoracic cage
D) muscles of inspiration

Question 52

Factors that influence the rate and depth of breathing include .

A) thalamic control
B) stretch receptors in the alveoli
C) voluntary cortical control
D) temperature of alveolar air

Question 53

The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressures of gases in the mixture" paraphrases .

A) Charles' law
B) Boyle's law
C) Henry's law
D) Dalton's law

Question 54

The local matching of blood flow with ventilation is _ _.

A) ventilation- perfusion coupling
B) the Bohr effect
C) the Haldane effect
D) chloride shifting

Question 55

Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation?

A) coryza
B) tuberculosis
C) emphysema
D) pneumonia

Question 56

How is it possible to change the pitch of our voice from high to low?

Question 57

Select the correct statement about oxygen transport in blood.

A) A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal.
B) During normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O₂.
C) During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently.
D) Increased BPG levels in the red blood cells enhance oxygen- carrying capacity.

Question 58

Intrapulmonary pressure is the .

A) pressure within the alveoli of the lungs
B) pressure within the pleural cavity
C) negative pressure in the intrapleural space
D) difference between atmospheric pressure and respiratory pressure

Question 59

Distinguish among anemic, ischemic, histotoxic, and hypoxemic hypoxia.

Question 60

The factors responsible for holding the lungs to the thorax wall are .

A) the visceral pleurae and the changing volume of the lungs
B) the smooth muscles of the lung
C) surface tension from pleural fluid and negative pressure in the pleural cavity
D) the diaphragm and the intercostal muscles alone

Question 61

A disorder characterized by permanent enlargement of the alveoli accompanied by destruction of the alveolar walls is .

Question 62

The contraction of the diaphragm and the external intercostal muscles begins inspiration. Explain exactly what happens, in terms of volume and pressure changes in the lungs, when these muscles contract.

Question 63

Figure 22.1Using Figure 22.1, match the following:
Trachea.

Question 64

Figure 22.2Using Figure 22.2, match the following:
Tidal volume.

Question 65

Figure 22.1Using Figure 22.1, match the following:
The archway in the back of the throat is called the .

Question 66

How is alveolar gas exchange affected by emphysema and pneumonia?

Question 67

The Bohr effect refers to the unloading of in a RBC due to declining pH.

Question 68

What is the chloride shift and why does it occur?

Question 69

The cartilaginous flap that closes the trachea during swallowing is called the _.

Question 70

The law of partial pressure is called

Question 71

Type II alveolar cells secrete _ _.

Question 72

Figure 22.2Using Figure 22.2, match the following:
Expiratory reserve volume.

Question 73

Figure 22.2Using Figure 22.2, match the following:
Residual volume.

Question 74

The partial pressure gradient for oxygen (in the body) is much steeper than that for carbon dioxide. Explain how equal amounts of these two gases can be exchanged (in a given time interval) in the lungs and at the tissues.

Question 75

Briefly differentiate between atmospheric pressure, intrapulmonary pressure, and intrapleural pressure. Which of these is always negative in a healthy individual during normal breathing? What happens if intrapleural pressure becomes equal to atmospheric pressure?

Question 76

Figure 22.2Using Figure 22.2, match the following:
Air that does not participate in the exchange of gases.

Question 77

Figure 22.1Using Figure 22.1, match the following:
Terminal bronchioles are lined with epithelium.

Question 78

If a baby is born at 28 weeks' gestation, what major problem will the doctors look for?

Question 79

Figure 22.1Using Figure 22.1, match the following:
Main (primary) bronchus.

Question 80

Figure 22.2Using Figure 22.2, match the following:
Inspiratory reserve volume.