Respiratory Pathophysiology Practice Questions

62 multiple-choice questions on Respiratory pathophysiology for paramedic and EMT students, from Chapter 9 (Pathophysiology). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

62 practice questions

1. Hypoxia refers to:

   1. A. Low oxygen content in arterial blood
   2. B. Reduced red cell count in the blood
   3. C. Inadequate oxygen at the tissue level
   4. D. Excess carbon dioxide in the blood
   Show answer

   Answer: C. Inadequate oxygen at the tissue level

   Hypoxemia specifically means low oxygen in the blood.

2. Ventilation and respiration differ in that ventilation is:

   1. A. Transporting oxygen on hemoglobin
   2. B. Using oxygen inside the mitochondria
   3. C. Moving air into and out of the lungs
   4. D. Exchanging gases across the alveoli
   Show answer

   Answer: C. Moving air into and out of the lungs

   A patient can ventilate well and still fail to oxygenate. Ventilation is mechanical; respiration is gas exchange.

3. A ventilation/perfusion mismatch means:

   1. A. Ventilation and perfusion are exactly equal
   2. B. Hemoglobin cannot release oxygen to tissues
   3. C. The main airway is completely obstructed
   4. D. Ventilation and perfusion are unevenly matched
   Show answer

   Answer: D. Ventilation and perfusion are unevenly matched

   It is the most common cause of hypoxemia. Some areas are ventilated but not perfused, or perfused but not ventilated.

4. Pneumonia impairs oxygenation by:

   1. A. Narrowing the trachea and large bronchi
   2. B. Thickening the chest wall and limiting expansion
   3. C. Filling alveoli so blood passes unoxygenated
   4. D. Reducing blood flow through the pulmonary arteries
   Show answer

   Answer: C. Filling alveoli so blood passes unoxygenated

   This creates a shunt: perfusion without ventilation. Fluid and debris fill the alveoli.

5. Obstructive lung disease is characterized by:

   1. A. Reduced lung volume from chest wall limitation
   2. B. Difficulty getting air in from stiff lungs
   3. C. Fluid filling alveoli and impairing diffusion
   4. D. Difficulty getting air out, with air trapping
   Show answer

   Answer: D. Difficulty getting air out, with air trapping

   Asthma, COPD, and bronchiectasis are examples.

6. Restrictive lung disease is characterized by:

   1. A. Increased residual volume and hyperinflation
   2. B. Airway narrowing with diffuse expiratory wheezing
   3. C. Air trapping with prolonged expiratory phase
   4. D. Reduced lung expansion from stiff lungs or chest wall
   Show answer

   Answer: D. Reduced lung expansion from stiff lungs or chest wall

   Pulmonary fibrosis and severe kyphoscoliosis are examples.

7. Air trapping in COPD leads to:

   1. A. Hyperinflation and a flattened diaphragm
   2. B. Reduced residual volume and lung collapse
   3. C. Improved gas exchange from larger alveoli
   4. D. A narrower chest and a domed diaphragm
   Show answer

   Answer: A. Hyperinflation and a flattened diaphragm

   Auto-PEEP can also reduce venous return during ventilation. Work of breathing increases.

8. Bronchospasm causes:

   1. A. Fluid leaking into the alveolar spaces
   2. B. Spasm of the diaphragm and chest wall
   3. C. Collapse of alveoli from lost surfactant
   4. D. Smooth muscle narrowing of the airways
   Show answer

   Answer: D. Smooth muscle narrowing of the airways

   Inflammation and mucus usually accompany it. It produces wheezing and prolonged expiration.

9. Pulmonary edema impairs gas exchange by:

   1. A. Air collapsing the lung from the pleura
   2. B. Mucus plugs blocking the larger bronchi
   3. C. Clots reducing pulmonary capillary flow
   4. D. Fluid widening the alveolar-capillary gap
   Show answer

   Answer: D. Fluid widening the alveolar-capillary gap

   Cardiogenic pulmonary edema comes from left heart failure. The fluid increases the diffusion distance.

10. Acute respiratory distress syndrome involves:

    1. A. Upper airway swelling with partial obstruction
    2. B. Diffuse alveolar injury with capillary leak
    3. C. Left heart failure with backup into the lungs
    4. D. Diffuse bronchospasm with mucus plugging
    Show answer

    Answer: B. Diffuse alveolar injury with capillary leak

    It follows sepsis, trauma, aspiration, and other severe insults. Severe hypoxemia results.

11. Ventilatory failure is best identified by:

    1. A. Tachypnea above 30 breaths per minute
    2. B. Audible wheezing on auscultation
    3. C. Rising CO2 with respiratory acidosis
    4. D. Low oxygen saturation by itself
    Show answer

    Answer: C. Rising CO2 with respiratory acidosis

    A tiring patient may have a falling rate with rising CO2.

12. A patient with severe asthma whose wheezing disappears and breath sounds become quiet is:

    1. A. Likely anxious and hyperventilating instead
    2. B. Responding well to the bronchodilator
    3. C. Improving, as the bronchospasm resolves
    4. D. Worsening, with too little airflow to wheeze
    Show answer

    Answer: D. Worsening, with too little airflow to wheeze

    A silent chest is an ominous sign.

13. Respiratory failure is defined as:

    1. A. Persistent productive cough with dyspnea
    2. B. A respiratory rate below 10 per minute
    3. C. Any sustained respiratory rate above 24 per minute
    4. D. Inability to maintain oxygenation or ventilation
    Show answer

    Answer: D. Inability to maintain oxygenation or ventilation

    Hypoxemic or hypercapnic.

14. Hypoxemic respiratory failure involves:

    1. A. Low CO2 from an excessive ventilation rate
    2. B. Rising CO2 from inadequate ventilation
    3. C. Normal oxygen with a high CO2 level
    4. D. Low oxygen despite adequate ventilation
    Show answer

    Answer: D. Low oxygen despite adequate ventilation

    Pneumonia, ARDS, pulmonary edema.

15. An opioid overdose patient has a respiratory rate of 6, SpO2 94% on oxygen, and ETCO2 72 mm Hg. Which problem is primary?

    1. A. Hypercapnic (ventilatory) failure
    2. B. Hypoxemic failure with adequate ventilation
    3. C. Primary metabolic acidosis
    4. D. Hyperventilation with low CO2
    Show answer

    Answer: A. Hypercapnic (ventilatory) failure

    High ETCO2 with slow breathing shows inadequate ventilation, with CO2 retention and respiratory acidosis. Supplemental oxygen can keep SpO2 normal and hide it. This patient needs assisted ventilation and naloxone. Hypoxemic failure involves low oxygen with normal or low CO2. The acidosis here is respiratory, from retained CO2, not primarily metabolic, and a rate of 6 with high CO2 is the opposite of hyperventilation.

16. Causes of hypoventilation include:

    1. A. Sepsis, salicylate toxicity, or hypoxia
    2. B. Anxiety, pain, fever, sepsis, or metabolic acidosis
    3. C. CNS depression, neuromuscular weakness, or obstruction
    4. D. Pulmonary embolism, altitude, or early asthma
    Show answer

    Answer: C. CNS depression, neuromuscular weakness, or obstruction

    Many pathways to the same result. Chest wall problems also cause it.

17. Shunt refers to:

    1. A. Ventilation without perfusion
    2. B. Perfusion without ventilation
    3. C. Diffusion across a thickened membrane
    4. D. Matched ventilation and perfusion
    Show answer

    Answer: B. Perfusion without ventilation

    Oxygen does not fix a true shunt.

18. Dead space refers to:

    1. A. Fluid-filled, unventilated alveoli
    2. B. Matched ventilation and perfusion
    3. C. Ventilation without perfusion
    4. D. Perfusion without ventilation
    Show answer

    Answer: C. Ventilation without perfusion

    Pulmonary embolism.

19. Diffusion impairment occurs with:

    1. A. Alveoli perfused but not ventilated
    2. B. Obstruction of the trachea or main bronchi
    3. C. A thickened alveolar-capillary membrane
    4. D. Alveoli ventilated but not perfused
    Show answer

    Answer: C. A thickened alveolar-capillary membrane

    Worse with exertion. Fibrosis and edema are examples.

20. Hypoxia at altitude results from:

    1. A. Thickening of the alveolar membrane
    2. B. Shunting of blood past collapsed alveoli
    3. C. Lower percentage of oxygen in the air
    4. D. Lower partial pressure of inspired oxygen
    Show answer

    Answer: D. Lower partial pressure of inspired oxygen

    Same percentage, lower pressure.

21. Asthma pathophysiology involves:

    1. A. Fluid accumulation in the pleural space
    2. B. Alveolar wall destruction and lost recoil
    3. C. Airway inflammation, bronchospasm, and mucus
    4. D. Protein-rich fluid leaking into the alveoli
    Show answer

    Answer: C. Airway inflammation, bronchospasm, and mucus

    Reversible, unlike COPD.

22. Asthma triggers include:

    1. A. Allergens only, through IgE-mediated reactions
    2. B. Exercise only, through airway cooling and drying
    3. C. Allergens, infection, exercise, and cold air
    4. D. No identifiable trigger in most patients
    Show answer

    Answer: C. Allergens, infection, exercise, and cold air

    Trigger identification guides prevention. Irritants and stress are also triggers.

23. Status asthmaticus is:

    1. A. Severe asthma unresponsive to initial treatment
    2. B. Asthma that resolved after one nebulizer
    3. C. Mild asthma controlled with an inhaler at home
    4. D. Chronic asthma with daily but stable symptoms
    Show answer

    Answer: A. Severe asthma unresponsive to initial treatment

    Life-threatening.

24. Signs of severe asthma include:

    1. A. Loud wheezing with a normal speaking pattern
    2. B. Prolonged expiration with full sentences
    3. C. A mild dry cough and normal oxygen saturation
    4. D. Speaking in words only and a silent chest
    Show answer

    Answer: D. Speaking in words only and a silent chest

    Fatigue precedes arrest. Accessory muscle use is another sign.

25. Air trapping in asthma leads to:

    1. A. Reduced lung volume and alveolar collapse
    2. B. Normal lung volumes with fast expiration
    3. C. Improved gas exchange from larger lung volume
    4. D. Hyperinflation and increased work of breathing
    Show answer

    Answer: D. Hyperinflation and increased work of breathing

    Prolonged expiration.

26. Ventilating an asthma patient requires:

    1. A. Fast rates to blow off retained CO2
    2. B. Slow rates with long expiratory time
    3. C. Large tidal volumes to open airways
    4. D. High pressures to overcome bronchospasm
    Show answer

    Answer: B. Slow rates with long expiratory time

    Auto-PEEP causes hypotension. Long exhalation prevents breath stacking.

27. COPD includes:

    1. A. Emphysema and chronic bronchitis
    2. B. Pulmonary fibrosis and sarcoidosis
    3. C. Pneumonia and pleural effusion
    4. D. Asthma and pulmonary fibrosis
    Show answer

    Answer: A. Emphysema and chronic bronchitis

    Often both coexist.

28. Emphysema causes:

    1. A. Fibrotic scarring that stiffens the lungs
    2. B. Mucus hypersecretion and productive cough
    3. C. Alveolar filling with fluid and debris
    4. D. Alveolar wall destruction and air trapping
    Show answer

    Answer: D. Alveolar wall destruction and air trapping

    Pink puffer. Elastic recoil is lost.

29. Chronic bronchitis causes:

    1. A. Pleural fluid compressing the lower lobes
    2. B. Alveolar wall destruction with loss of elastic recoil
    3. C. Airway inflammation and mucus hypersecretion
    4. D. Fibrous scarring that makes lungs stiff
    Show answer

    Answer: C. Airway inflammation and mucus hypersecretion

    Blue bloater. It produces a chronic productive cough.

30. COPD exacerbation is commonly triggered by:

    1. A. A sudden drop in temperature
    2. B. Seasonal pollen allergies
    3. C. Strenuous physical exercise
    4. D. Respiratory infection
    Show answer

    Answer: D. Respiratory infection

    Also air pollution and nonadherence.

31. Chronic carbon dioxide retention in COPD leads to:

    1. A. Renal bicarbonate retention
    2. B. Compensatory hyperventilation
    3. C. Renal bicarbonate excretion
    4. D. Chronic respiratory alkalosis
    Show answer

    Answer: A. Renal bicarbonate retention

    A minority depend on hypoxic drive. The kidneys compensate for chronic respiratory acidosis.

32. Oxygen in COPD should be:

    1. A. Given at 15 L/min by nonrebreather
    2. B. Titrated to about 88 to 92 percent
    3. C. Given only if cyanosis is present
    4. D. Withheld to protect the hypoxic drive
    Show answer

    Answer: B. Titrated to about 88 to 92 percent

    Avoid both hypoxia and excessive oxygen.

33. A patient with lobar pneumonia remains hypoxic despite high-flow oxygen. The main reason is:

    1. A. He is hyperventilating and blowing off oxygen
    2. B. His airways are completely obstructed by mucus
    3. C. His hemoglobin is already fully saturated with oxygen
    4. D. Blood passes alveoli full of exudate (shunt)
    Show answer

    Answer: D. Blood passes alveoli full of exudate (shunt)

    Consolidated alveoli are full of exudate, so blood flowing past them picks up no oxygen. This is a shunt, and extra inspired oxygen cannot reach those alveoli. Hyperventilation lowers CO2 but doesn't cause hypoxia. Airway obstruction would cause absent air movement. If his hemoglobin were fully saturated, he would not be hypoxic.

34. Aspiration pneumonia results from:

    1. A. Viral infection of the upper airway
    2. B. Inhaling gastric contents or secretions
    3. C. Bloodstream infection seeding the lungs
    4. D. An allergic reaction in the bronchi
    Show answer

    Answer: B. Inhaling gastric contents or secretions

    Altered mental status is the main risk.

35. Pulmonary edema types include:

    1. A. Infectious only, from pneumonia
    2. B. Cardiogenic only, from left heart failure
    3. C. Noncardiogenic only, from capillary leak
    4. D. Cardiogenic and noncardiogenic
    Show answer

    Answer: D. Cardiogenic and noncardiogenic

    Treatment differs. Cardiogenic comes from left heart failure; noncardiogenic from capillary leak.

36. A septic patient develops severe hypoxemia with bilateral infiltrates and no heart failure. Why do the lungs become stiff?

    1. A. Bronchospasm traps air in the lungs and stiffens them
    2. B. Protein-rich fluid floods alveoli and removes surfactant
    3. C. Pleural air collapses one lung and pushes on the other
    4. D. The diaphragm is paralyzed and cannot expand the lungs
    Show answer

    Answer: B. Protein-rich fluid floods alveoli and removes surfactant

    In ARDS, inflammation injures the alveolar-capillary membrane. Protein-rich fluid leaks into the alveoli, surfactant is destroyed, and alveoli collapse, so the lungs become stiff (low compliance) and shunt blood. Bronchospasm causes wheezing, pneumothorax is one-sided, and diaphragm paralysis does not cause infiltrates.

37. ARDS triggers include:

    1. A. Major trauma only, through lung contusion
    2. B. Sepsis only, through systemic inflammation
    3. C. Sepsis, trauma, aspiration, and pancreatitis
    4. D. Pneumonia only, through direct lung infection
    Show answer

    Answer: C. Sepsis, trauma, aspiration, and pancreatitis

    Direct and indirect lung injury. Transfusion is another trigger.

38. Pneumothorax pathophysiology involves:

    1. A. Bronchospasm trapping air in the alveoli
    2. B. Fluid filling the alveoli and small airways
    3. C. Blood in the pleural space compressing the lung
    4. D. Air in the pleural space collapsing the lung
    Show answer

    Answer: D. Air in the pleural space collapsing the lung

    Spontaneous, traumatic, or iatrogenic.

39. Spontaneous pneumothorax typically occurs in:

    1. A. Young children after viral illness
    2. B. Muscular athletes during heavy weight lifting
    3. C. Older women with heart failure
    4. D. Tall, thin young men and COPD patients
    Show answer

    Answer: D. Tall, thin young men and COPD patients

    Rupture of a bleb.

40. Tension pneumothorax develops when:

    1. A. Air enters the pleural space but cannot escape
    2. B. Air escapes freely through an open chest wound
    3. C. Blood accumulates rapidly in the pleural space
    4. D. Fluid slowly fills the pleural space
    Show answer

    Answer: A. Air enters the pleural space but cannot escape

    One-way valve. Pressure builds with each breath.

41. Signs of tension pneumothorax include:

    1. A. Diffuse wheezing and prolonged expiration
    2. B. Equal breath sounds with bilateral crackles
    3. C. Absent breath sounds, JVD, and hypotension
    4. D. Flat neck veins and widened pulse pressure
    Show answer

    Answer: C. Absent breath sounds, JVD, and hypotension

    Treat on clinical suspicion. Tracheal deviation is a late sign.

42. Hemothorax pathophysiology involves:

    1. A. Air trapped in the pleural space
    2. B. Lymph leaking into the pleural space
    3. C. Blood in the pleural space
    4. D. Pus collecting in the pleural space
    Show answer

    Answer: C. Blood in the pleural space

    Can cause both respiratory and hypovolemic compromise. The blood comes from vessel or lung injury.

43. Flail chest pathophysiology involves:

    1. A. A sternal fracture with cardiac contusion
    2. B. A single rib fracture with sharp pleuritic pain
    3. C. Pneumothorax without any rib fractures
    4. D. A paradoxically moving segment over a contusion
    Show answer

    Answer: D. A paradoxically moving segment over a contusion

    The contusion causes the hypoxia.

44. Pulmonary contusion causes:

    1. A. Air leaking from the lung into the pleural space
    2. B. Chest wall pain without any lung injury
    3. C. Lung bleeding and edema that worsen over hours
    4. D. Immediate, maximal hypoxia that then improves
    Show answer

    Answer: C. Lung bleeding and edema that worsen over hours

    Delayed hypoxia.

45. Pulmonary embolism sources include:

    1. A. Leg vein clots only, never other material
    2. B. Arterial plaque fragments from the carotids
    3. C. Venous clots, fat, air, or amniotic fluid
    4. D. Clots from the left atrium in atrial fibrillation
    Show answer

    Answer: C. Venous clots, fat, air, or amniotic fluid

    DVT is the most common. Leg and pelvic vein clots predominate.

46. Pulmonary embolism signs include:

    1. A. Gradual dyspnea over weeks with orthopnea
    2. B. Sudden dyspnea, pleuritic pain, and tachycardia
    3. C. High fever, productive cough, and rigors
    4. D. Diffuse wheezing with prolonged expiration
    Show answer

    Answer: B. Sudden dyspnea, pleuritic pain, and tachycardia

    Often nonspecific. Hypoxia is also common.

47. Pulmonary hypertension causes:

    1. A. Left ventricular hypertrophy and failure
    2. B. Bronchospasm from airway irritation
    3. C. Cardiogenic pulmonary edema from backflow
    4. D. Right heart strain and eventual failure
    Show answer

    Answer: D. Right heart strain and eventual failure

    Cor pulmonale.

48. Pleural effusion causes:

    1. A. Bronchospasm from pleural irritation
    2. B. Lung compression by pleural fluid
    3. C. Air trapping from narrowed small airways
    4. D. Fluid filling the alveoli themselves
    Show answer

    Answer: B. Lung compression by pleural fluid

    Heart failure, infection, cancer.

49. Upper airway obstruction causes include:

    1. A. Foreign bodies only, mostly in children
    2. B. Trauma only, from blunt neck injury
    3. C. Swelling only, from allergic reactions
    4. D. Tongue, foreign body, swelling, or trauma
    Show answer

    Answer: D. Tongue, foreign body, swelling, or trauma

    Infection is another cause. The tongue is the most common cause in the unresponsive patient.

50. Epiglottitis pathophysiology involves:

    1. A. Viral swelling below the vocal cords
    2. B. Alveolar consolidation in the lower lobes
    3. C. Bronchiolar inflammation in infants
    4. D. Rapid swelling of the epiglottis
    Show answer

    Answer: D. Rapid swelling of the epiglottis

    Drooling, stridor, tripod position.

51. Croup pathophysiology involves:

    1. A. Viral inflammation of the larynx and trachea
    2. B. Viral inflammation of the small bronchioles
    3. C. Bacterial consolidation of the alveoli
    4. D. Bacterial swelling of the epiglottis
    Show answer

    Answer: A. Viral inflammation of the larynx and trachea

    Usually children under 5. It causes stridor and a barking cough.

52. Anaphylaxis affects the airway through:

    1. A. Upper airway edema and bronchospasm
    2. B. Bronchospasm alone, without edema
    3. C. Pleural fluid compressing the lungs
    4. D. Alveolar fluid from heart failure
    Show answer

    Answer: A. Upper airway edema and bronchospasm

    Both must be treated.

53. Carbon monoxide affects the respiratory system by:

    1. A. Obstructing the airways with soot
    2. B. Causing alveolar edema directly
    3. C. Displacing oxygen from hemoglobin
    4. D. Triggering diffuse bronchospasm
    Show answer

    Answer: C. Displacing oxygen from hemoglobin

    Saturation reads falsely normal. It also impairs cellular oxygen use.

54. Cyanide affects cells by:

    1. A. Binding hemoglobin in place of oxygen
    2. B. Causing airway swelling and obstruction
    3. C. Blocking oxygen use in the mitochondria
    4. D. Causing alveolar fluid accumulation
    Show answer

    Answer: C. Blocking oxygen use in the mitochondria

    Blood is oxygenated but cells cannot use it.

55. Smoke inhalation causes injury through:

    1. A. Thermal injury to the lower airways only
    2. B. Soot particles alone, without chemical injury
    3. C. Heat, particulates, irritants, CO, and cyanide
    4. D. Carbon monoxide poisoning without other injury
    Show answer

    Answer: C. Heat, particulates, irritants, CO, and cyanide

    Multiple mechanisms.

56. Neuromuscular diseases affect breathing by:

    1. A. Obstructing the upper airway with edema
    2. B. Damaging alveoli and reducing diffusion
    3. C. Triggering bronchospasm and mucus
    4. D. Weakening respiratory muscles and cough
    Show answer

    Answer: D. Weakening respiratory muscles and cough

    Guillain-Barré and myasthenia gravis.

57. Obesity hypoventilation syndrome involves:

    1. A. Fluid-filled alveoli from heart failure
    2. B. Upper airway obstruction during sleep alone
    3. C. Alveolar wall destruction from years of smoking
    4. D. Stiff chest wall and blunted respiratory drive
    Show answer

    Answer: D. Stiff chest wall and blunted respiratory drive

    Often with sleep apnea. The result is chronic hypercapnia.

58. Hyperventilation syndrome:

    1. A. Is always psychogenic and needs no further workup
    2. B. May be anxiety, but serious causes must be excluded
    3. C. Is never dangerous and resolves on its own
    4. D. Is best treated by rebreathing into a paper bag
    Show answer

    Answer: B. May be anxiety, but serious causes must be excluded

    PE and DKA also cause hyperventilation.

59. Respiratory assessment relies on:

    1. A. Respiratory rate alone, as the earliest sign
    2. B. Pulse oximetry alone, as the most objective sign
    3. C. Breath sounds alone, as the most specific sign
    4. D. Rate, effort, sounds, SpO2, and capnography together
    Show answer

    Answer: D. Rate, effort, sounds, SpO2, and capnography together

    No single measure suffices. Mental status also matters.

60. Capnography in respiratory distress helps by:

    1. A. Counting respiratory rate and nothing else
    2. B. Showing ventilation and bronchospasm patterns
    3. C. Measuring airway pressure during each breath
    4. D. Measuring arterial oxygen content directly
    Show answer

    Answer: B. Showing ventilation and bronchospasm patterns

    Shark fin waveform in bronchospasm.

61. Pediatric respiratory failure differs because children:

    1. A. Fatigue faster and arrest more suddenly
    2. B. Have greater oxygen reserve than adults
    3. C. Compensate indefinitely without tiring
    4. D. Rarely progress to respiratory arrest
    Show answer

    Answer: A. Fatigue faster and arrest more suddenly

    Most pediatric arrests are respiratory.

62. Aging affects respiratory pathophysiology by:

    1. A. Improving gas exchange through larger alveoli
    2. B. Increasing reserve through chest wall stiffening
    3. C. Having no meaningful effect on lung function
    4. D. Reducing reserve, cough strength, and immunity
    Show answer

    Answer: D. Reducing reserve, cough strength, and immunity

    Pneumonia is deadlier in older adults.