Respiratory System

1. The primary function of the nasal cavity in respiration is to:

Produce surfactant for the alveoli Warm, humidify, and filter inspired air Store oxygen for later use Generate action potentials for breathing rhythm

2. Which structure connects the pharynx to the trachea and contains the vocal cords?

Bronchus Larynx Epiglottis Alveolar duct

3. The trachea is reinforced by C-shaped cartilage rings that:

Prevent collapse of the airway during breathing Increase surface area for gas exchange Produce mucus to trap pathogens Permit only one-way airflow

4. The conducting zone of the respiratory system includes all of the following EXCEPT:

Trachea Primary bronchi Terminal bronchioles Alveolar sacs

5. The respiratory zone, where gas exchange occurs, begins at the:

Segmental bronchi Respiratory bronchioles Terminal bronchioles Trachea

6. Which of the following structures is directly responsible for gas exchange with the pulmonary capillaries?

Alveoli Bronchi Larynx Pleural cavity

7. The right lung normally has:

Two lobes and a cardiac notch Three lobes and a cardiac notch Three lobes and no cardiac notch Two lobes and no fissures

8. The thin space between the visceral and parietal pleura normally contains:

Air at atmospheric pressure Pleural fluid that reduces friction Surfactant to prevent alveolar collapse Lymph to drain excess interstitial fluid

9. Which muscles are primarily responsible for quiet inspiration at rest?

Internal intercostals and rectus abdominis Diaphragm and external intercostals Sternocleidomastoids only Scalenes and trapezius

10. During forced expiration, which muscles are most active?

Diaphragm only External intercostals and diaphragm Internal intercostals and abdominal muscles Sternocleidomastoids and scalenes

11. The alveolar walls and capillaries together form the respiratory membrane whose primary function is to:

Generate surfactant Regulate respiratory rate Maximize diffusion of gases Protect against pathogens via cilia

12. Type II alveolar cells primarily:

Form the blood–air barrier Produce pulmonary surfactant Carry oxygen in the blood Regulate respiratory rhythm

13. Surfactant reduces the surface tension within alveoli, which:

Increases the work of breathing Promotes alveolar collapse Helps keep alveoli open during expiration Prevents oxygen diffusion into blood

14. Which part of the brainstem contains major respiratory control centers?

Hypothalamus Medulla oblongata and pons Cerebellum Basal ganglia

15. The hilum of the lung is the region where:

Alveoli attach directly to the diaphragm Primary bronchi, pulmonary vessels, and nerves enter and leave Surfactant is stored Gas exchange is maximal

16. According to Boyle’s law, at a constant temperature, the pressure of a gas is:

Directly proportional to its volume Inversely proportional to its volume Unrelated to its volume Dependent only on temperature

17. During inspiration, thoracic volume increases and alveolar pressure:

Increases above atmospheric pressure Remains unchanged Decreases below atmospheric pressure Equals intrapleural pressure

18. Dalton’s law describes how the total pressure of a gas mixture relates to:

The solubility of each gas in water The sum of the partial pressures of each gas The volume and temperature of the container The pH of the blood

19. Henry’s law is most relevant in respiration because it explains that:

Gas volume is proportional to temperature Gases move from low to high partial pressure The amount of gas dissolved in a liquid depends on its partial pressure and solubility Gas diffusion is independent of partial pressure

20. At the level of the alveolus, oxygen diffusion into blood is driven primarily by:

The pH difference between alveolar air and blood The partial pressure gradient between alveolar air and capillary blood The presence of surfactant in the alveoli The osmotic pressure of plasma proteins

21. Intrapleural pressure is normally:

Slightly positive relative to atmospheric pressure Equal to atmospheric pressure Slightly negative relative to atmospheric pressure Zero during the entire respiratory cycle

22. Compliance of the lungs refers to:

The amount of air remaining after maximal expiration The ability of the lungs to stretch and expand for a given change in pressure The rate at which air moves through the airways The resistance to airflow in the bronchioles

23. Low lung compliance, as in pulmonary fibrosis, typically results in:

Easier lung inflation Increased tidal volume Increased work of breathing Decreased elastic recoil

24. An increase in airway resistance, as in asthma, will:

Decrease the work required to breathe Have no effect on ventilation Increase the work required to move air in and out Increase vital capacity

25. The volume of air inhaled or exhaled in a normal, quiet breath is called:

Vital capacity Residual volume Tidal volume Inspiratory reserve volume

26. The air that remains in the lungs after maximal forced expiration is:

Residual volume Tidal volume Dead space volume Expiratory reserve volume

27. Anatomical dead space refers to:

The volume of air in the alveoli not participating in gas exchange The volume of air in the conducting airways where no gas exchange occurs The residual volume after forced expiration The volume of blood in the pulmonary capillaries

28. A mismatch of ventilation and perfusion in the lung is referred to as:

Dead space only Shunt only V/Q inequality Hyperbaric ventilation

29. In a healthy lung at rest, ventilation and perfusion are generally greatest at the:

Apex (top) Base (bottom) Middle zones only Equally distributed from apex to base

30. Increasing the partial pressure of oxygen in inspired air primarily affects:

The solubility of carbon dioxide The diffusion capacity of nitrogen The alveolar and arterial PO₂ The anatomical dead space

31. Most oxygen in the blood is transported:

Dissolved in plasma Bound to hemoglobin in red blood cells As bicarbonate ions Bound to plasma proteins

32. The oxyhemoglobin dissociation curve shows the relationship between:

Blood pH and PCO₂ Hemoglobin saturation and PO₂ Cardiac output and blood pressure Tidal volume and respiratory rate

33. A rightward shift of the oxyhemoglobin dissociation curve indicates that, at any given PO₂, hemoglobin:

Has a higher affinity for oxygen Releases oxygen more readily Cannot bind oxygen at all Is unaffected by pH or temperature

34. Conditions that favor a rightward shift of the oxyhemoglobin curve include:

Decreased temperature, increased pH, decreased PCO₂ Increased temperature, decreased pH, increased PCO₂ Decreased temperature and decreased 2,3-BPG None of the above

35. The Bohr effect describes how:

CO₂ increases hemoglobin affinity for oxygen Lower pH and higher CO₂ promote oxygen unloading from hemoglobin Oxygen binding increases CO₂ carrying capacity Hemoglobin saturation is independent of pH

36. The Haldane effect refers to the phenomenon that:

Deoxygenated blood can carry more CO₂ than oxygenated blood Oxygenated blood can carry more CO₂ than deoxygenated blood Hemoglobin cannot bind CO₂ CO₂ and O₂ bind to the same site on hemoglobin

37. About 70% of carbon dioxide in the blood is transported primarily:

Dissolved in plasma As carbaminohemoglobin As bicarbonate ions (HCO₃^-) in plasma Bound to plasma proteins

38. The enzyme that catalyzes the conversion of CO₂ and water to carbonic acid in red blood cells is:

Hemoglobinase Carbonic anhydrase Lactate dehydrogenase Carbon dioxide synthase

39. The “chloride shift” describes the movement of:

Chloride out of RBCs when CO₂ enters Chloride into RBCs as bicarbonate leaves Chloride into plasma as bicarbonate enters RBCs Chloride only in the lungs and not in tissues

40. In systemic tissues, oxygen moves:

From tissue cells into capillary blood From capillary blood into tissue cells Equally in both directions Not at all, because only CO₂ moves

41. In the lungs, CO₂ moves primarily:

From alveoli into capillary blood From capillary blood into alveolar air Equally in both directions Only bound to plasma proteins

42. Hemoglobin is considered fully saturated with oxygen when:

Each hemoglobin molecule binds one oxygen molecule All four heme groups of hemoglobin are bound to oxygen Hemoglobin binds no oxygen Hemoglobin is denatured by heat

43. At the pulmonary capillaries, the high PO₂ environment promotes:

Unloading of oxygen from hemoglobin Loading of oxygen onto hemoglobin Conversion of oxygen to bicarbonate Formation of carbaminohemoglobin

44. In metabolically active tissues, increased CO₂ and temperature help:

Hemoglobin hold on to oxygen more tightly Hemoglobin release oxygen more readily Prevent oxygen delivery Eliminate the Bohr effect

45. Most of the CO₂ carried as bicarbonate is formed:

In the alveolar space In the plasma without enzymes Inside red blood cells with carbonic anhydrase Inside the mitochondria of tissue cells

46. The majority of oxygen that diffuses into the blood in the lungs:

Remains dissolved in plasma Immediately binds hemoglobin Is converted into CO₂ Is exhaled without binding

47. When blood passes through systemic capillaries, which change occurs?

Oxyhemoglobin concentration increases Hemoglobin releases oxygen and binds more CO₂ CO₂ is converted entirely to oxygen Hemoglobin becomes fully saturated with oxygen

48. In the pulmonary capillaries, as oxygen binds to hemoglobin, the ability of hemoglobin to carry CO₂:

Increases, favoring CO₂ loading Decreases, favoring CO₂ unloading Remains unchanged Causes hemoglobin to denature

49. Which statement best describes external respiration?

Gas exchange between systemic capillaries and tissues Gas exchange between alveoli and pulmonary capillaries Cellular use of oxygen in mitochondria Production of ATP from glucose

50. Internal respiration refers specifically to:

Ventilation of the lungs by the diaphragm Gas exchange between alveoli and pulmonary capillaries Gas exchange between systemic capillaries and tissue cells The binding of oxygen to hemoglobin

YOUR CART

Respiratory System & Gas Transport Quiz

50 Multiple Choice Questions – No Answers Shown