Deck 15: Regulation of Breathing

Question 1

Stimulation of the irritant receptors in the lung can result in which of the following?
1) Bronchoconstriction
2) Coughing
3) Narrowing of the glottis

A)1 only
B)1 and 3 only
C)1, 2, and 3
D)1 and 3 only

Answer 1

C

Question 2

Which of the following can cause laryngospasm and bradycardia through a vagovagal reflex?
1) Bronchoscopy
2) Endotracheal intubation
3) Tracheal suctioning

A)1 only
B)1 and 3 only
C)1, 2, and 3
D)1 and 2 only

Answer 2

C

Question 3

Where are the inspiratory and expiratory centers in the brain found?

A) Broca's area
B) Neurons in the cerebellum
C) Pons
D) No such centers exist

Answer 3

D
Explanation: Recent evidence shows that inspiratory and expiratory neurons are anatomically intermingled and do not necessarily inhibit one another. No clearly separate inspiratory and expiratory centers exist.

Question 4

What receptors are known to cause an increase in ventilation when the patient's limbs are moved or cold water is splashed on the patient's face?

A) Irritant receptors
B) J receptors
C) Muscle spindles
D) Peripheral proprioceptors

Question 5

Which statement(s) describe aspects of the Hering-Breuer reflex?
1) It affects the rate and depth of breathing during exercise.
2) It is only activated at large tidal volumes in normal adults.
3) Its impulses travel via the vagus nerve to the dorsal respiratory groups (DRGs).
4) Its receptors are located in the large and small airways.

A)1 only
B)1 and 2 only
C)2, 3, and 4 only
D)1, 2, 3, and 4

Question 6

Sensory input to the dorsal respiratory neurons from the lungs, airways, and peripheral chemoreceptors is provided via which nerves?
1) Glossopharyngeal
2) Phrenic
3) Vagus
4) Trigeminal

A)1 and 2 only
B)1, 2, and 4 only
C)1 and 3 only
D)2 and 3 only

Question 7

Which of the following control the inhibitory neurons that switch off the inspiratory ramp signal?
1) Apneustic center
2) Pneumotaxic center
3) Pulmonary stretch receptors

A)1, 2, and 3
B)1 and 2 only
C)3 only
D)2 and 3 only

Question 8

The medulla oblongata contains which of the following areas?
1) Apneustic center
2) Dorsal respiratory group neurons (DRGs)
3) Pneumotaxic center
4) Ventral respiratory group neurons (VRGs)

A)1, 2, and 3 only
B)2 and 4 only
C)3 only
D)1, 3, and 4 only

Question 9

Which receptors are primarily responsible for the initial increase in ventilation that occurs at the beginning of exercise?

A) Carotid chemoreceptors
B) Irritant receptors
C) J receptors
D) Proprioceptors

Question 10

What receptors cause a rapid shallow breathing pattern when stimulated by pulmonary disease?

A) Irritant receptors
B) J receptors
C) Muscle spindles
D) Peripheral proprioceptors

Question 11

What reflex is associated with the sensory stimulation of the pulmonary stretch receptors that stimulate a deeper breath upon inspiration?

A) Carotid
B) Head's paradoxical
C) Hering-Breuer
D) J receptor

Question 12

What is the effect when the deflation reflex is stimulated?

A) A strong inspiratory effort
B) Expiration is initiated
C) Cuts off all inspiratory signals
D) Stimulates the termination of expiration

Question 13

What stimulates the Hering-Breuer inflation reflex?

A) The DRG when it is time to end inspiratory efforts.
B) The stretch of receptors at high lung volumes.
C) The VRG when it is time for inspiration.
D) Very low lung volumes stimulate inspiration.

Question 14

The pneumotaxic center controls which of the following?

A) Response to changes in blood pH and PCO₂
B) Rhythm of the full breathing cycle
C) When inspiration switches off (the inspiratory time)
D) When inspiration switches on (the expiratory time)

Question 15

What receptors are associated with causing coughing, sneezing, and tachypnea when stimulated?

A) Irritant receptors
B) J receptors
C) Muscle spindles
D) Peripheral proprioceptors

Question 16

Which of the following can be stimulated by pulmonary J receptors?
1) Edema
2) Inflammatory processes
3) Pulmonary vascular congestion

A)1 and 3 only
B)1 only
C)1 and 3 only
D)1, 2, and 3

Question 17

To which anatomic structures do the ventral respiratory centers send motor signals during inspiration?
1) Diaphragm
2) Larynx
3) Pharynx
4) Sternocleidomastoids

A)1, 2, and 3 only
B)2 and 4 only
C)1 only
D)1, 2, and 4

Question 18

What centers are located in the pons of the brainstem?
1) Apneustic center
2) Dorsal respiratory neurons
3) Pneumotaxic center

A)1, 2, and 3
B)2 and 3 only
C)1 and 3 only
D)1 and 2 only

Question 19

Failure to switch off the brainstem inspiratory neurons can result in which of the following?

A) Apnea
B) Apneustic breathing
C) Biot's breathing
D) Cheyne-Stokes breathing

Question 20

What negative responses can be elicited by suctioning a patient's airway?
1) Tachycardia
2) Coughing
3) Laryngospasm
4) Severe bronchospasm

A)1, 2, and 3 only
B)2 and 4 only
C)1 and 3 only
D)2, 3, and 4 only

Question 21

In the face of hyperoxia, what is the response of the peripheral chemoreceptors to hypercapnia?

A) There is a decreased drive to breathe.
B) There is an increased drive to breathe.
C) There is insufficient information.
D) There is virtually no response.

Question 22

In the face of chronically elevated levels of CO₂, what happens to the response mediated by the central chemoreceptors?

A) It is accentuated or increased.
B) It is muted or decreased.
C) There is no change in the response.
D) There is no way to predict the body's response.

Question 23

Why does it take approximately 24 hr for a full ventilatory response to develop to acute hypoxemia?

A) Initial cerebrospinal fluid alkalemia blunts the hypoxic ventilatory stimulus.
B) Peripheral chemoreceptors are slow to respond to decreased blood O₂ levels.
C) Renal compensation for respiratory alkalosis increases chemoreceptor sensitivity.
D) A full ventilatory response is not possible until after the muscles become fatigued.

Question 24

Which of the following causes hypoxic stimulation of the carotid bodies?
1) Large decrease in arterial PO₂
2) Large decrease in O₂ content
3) CO poisoning

A)1 only
B)1 and 2 only
C)1, 2, and 3
D)1 and 3 only

Question 25

How should O₂ therapy be administered to chronically hypercapnic patients?

A) Avoid giving any supplemental O₂.
B) Give as much O₂ as possible (60% to 100%).
C) Withhold O₂ until the patient is intubated.
D) Give as much O₂ as required to maintain adequate oxygenation.

Question 26

When given high concentrations of O₂, a patient with chronic hypercapnia may develop a more serious respiratory acidosis. Which of the following might be contributing to the patient's increased PCO₂?
1) Worsening ventilation-perfusion (VV/QQ) balance
2) Desensitization of the carotid bodies
3) Removal of the hypoxic stimulus

A)1 and 2 only
B)1 only
C)1 and 3 only
D)1, 2, and 3

Question 27

Stimulation to increase ventilation does not occur until the PaO₂ falls below what level?

A) 90 mm Hg
B) 80 mm Hg
C) 70 mm Hg
D) 60 mm Hg

Question 28

Which of the following is indirectly responsible for minute-to-minute control of breathing?

A) CO₂ levels
B) HCO₃^-levels
C) Lactate levels
D) Oxygen (O₂) levels

Question 29

What is the response of a patient with chronic hypercapnia to a sudden acute rise in carbon dioxide?

A) In almost all of these patients, there will be no response.
B) The patient's drive to breathe will be increased.
C) This will further depress his or her respiratory centers.
D) This will induce apnea and sudden death.

Question 30

Which of the following will occur during even strenuous exercise in a normal healthy individual?

A) Blood gases remain stable.
B) The arterial PCO₂ rises.
C) The arterial pH falls.
D) The arterial PO₂ falls.

Question 31

In what manner would O₂ therapy induce worsening mismatch and thus a further elevation in CO₂ in a chronically hypercapnic patient?

A) By improving blood flow to poorly ventilated alveoli
B) By decreasing blood flow to poorly ventilated alveoli
C) Causing bronchoconstriction, which worsens gas flow to lowareas
D) Causing bronchodilation, which improves gas flow to poorly ventilated alveoli

Question 32

What happens in chronic hypercapnia?
1) The central chemoreceptive response to CO₂ is decreased.
2) The cerebrospinal fluid pH is restored to normal.
3) Responsiveness to increased CO₂ is decreased.

A)1 only
B)1 and 2 only
C)2 and 3 only
D)1, 2, and 3

Question 33

What group of nerve cells senses and responds to changes in the chemical composition of its fluid environment?

A) Chemoreceptors
B) Gamma-efferent system
C) Muscle spindle fibers
D) Proprioceptors

Question 34

What has the primary responsibility for sensing and responding to changes in blood levels of CO₂?

A) Apneustic centers
B) Central chemoreceptors
C) Peripheral chemoreceptors
D) Pneumotaxic center

Question 35

Which respond more rapidly to high levels of CO₂?

A) Aortic chemoreceptors
B) Carotid chemoreceptors
C) Central chemoreceptors
D) Ventral respiratory centers

Question 36

Both anemia and carbon monoxide (CO) poisoning can cause severe hypoxia, yet neither condition results in a major stimulation of breathing. Why is this so?

A) The peripheral chemoreceptors do not respond to low O₂ content.
B) Anemia and CO poisoning depresses the peripheral chemoreceptors.
C) Anemia and CO poisoning depresses the central chemoreceptors.
D) Anemia and CO cause stagnant hypoxia, not hypoxemia.

Question 37

Coexisting arterial hypoxemia, acidemia, and high PaCO₂ (i.e., asphyxia) will have what effect on the peripheral chemoreceptors?

A) There is a decreased drive to breathe.
B) There is a maximally increased drive to breathe.
C) There is insufficient information to make a determination.
D) There is virtually no response.

Question 38

Adjustment of respiratory muscle contractions to accommodate varying loads is regulated by which of the following?

A) Medullary respiratory centers
B) Muscle spindle fiber feedback
C) Pontine apneustic center
D) Pontine pneumotaxic center

Question 39

Which of the following centers responds more strongly to high levels of CO₂?

A) Aortic chemoreceptors
B) Carotid chemoreceptors
C) Central chemoreceptors
D) Ventral respiratory centers

Question 40

Where are the peripheral chemoreceptors located?
1) In the arch of the aorta
2) In the bifurcations of carotid arteries
3) On the ventrolateral surfaces of the medulla

A)1 and 2 only
B)2 only
C)2 and 3 only
D)1 and 3 only

Question 41

Biot's respiration is most frequently observed in patients with which of the following?

A) Congestive heart failure
B) Increased intracranial pressure
C) Metabolic acidosis
D) Peripheral nerve disorders

Question 42

Which of the following are causes of central neurogenic hyperventilation?
1) Head trauma
2) Inadequate brain blood flow
3) Severe brain hypoxia
4) Hypothermia

A)2 and 3 only
B)1 and 4 only
C)2 and 3 only
D)1, 2, and 3 only

Question 43

A healthy 33-year-old woman relocates to an area approximately 8000 ft above sea level. On her first day, she begins to hyperventilate, but in 24 hr she shows signs of recovery. What is the probable cause of her condition?

A) Hypoxemia-mediated hyperventilation
B) Hypercapnia
C) Hyperoxia-mediated hyperventilation
D) Increased H⁺

Question 44

What does apneustic breathing indicate?

A) Damage to the cerebrum
B) Damage to the pons
C) Spinal cord transaction
D) Vagal nerve damage

Question 45

You observe a patient's breathing pattern as very irregular, with periods of breathing interspersed with long periods of apnea. Which of the following terms would you use in charting this observation?

A) Apneustic breathing
B) Biot's respiration
C) Cheyne-Stokes breathing
D) Kussmaul's breathing

Question 46

Which of the following can cause Cheyne-Stokes breathing?
1) Brain injuries
2) Congestive heart failure
3) Metabolic acidosis

A)1 and 2 only
B)2 and 3 only
C)1 and 3 only
D)1, 2, and 3

Question 47

While observing a patient's breathing, you note that the depth and rate first increase, then decrease, followed by a period of apnea. Which of the following terms would you use in charting this observation?

A) Apneustic breathing
B) Biot's breathing
C) Cheyne-Stokes breathing
D) Paradoxical breathing

Question 48

Why does splashing cold water on the skin stimulate ventilation?

A) It decreases medullary inspiratory activity causing hyperpnea.
B) Hering-Breuer inflation reflex.
C) It increases medullary inspiratory activity causing hyperpnea.
D) J receptor.

Question 49

A patient in the emergency room is displaying prolong inspiratory gasps interrupted by occasional expirations, what serious injury should be suspected on this patient?
1) Pneumotaxic center has been severed.
2) Vagus nerve has been severed.
3) Glossopharyngeal nerve has been severed.

A)2 and 3 only
B)1 and 2 only
C)1 and 3 only
D)1, 2, and 3

Question 50

In patients with closed-head injuries, what may happen in the presence of hypercapnia?

A) High CO₂ increases the risk of psychotic events.
B) High CO₂ levels cause cerebral vasodilation and improved oxygenation.
C) Severe cerebral vasoconstriction results in anoxia and stroke.
D) Vasodilation causes increased intracranial pressure and possibly stops blood flow.