Questions About Respiratory System: characteristics, organs, and disorders
Multiple-Choice Questions: Respiratory System
1. What is the primary function of the respiratory system?
A) Circulate blood
B) Digest food
C) Exchange gases
D) Eliminate waste
E) Control temperature
2. Which of the following is the site of gas exchange in the lungs?
A) Bronchi
B) Trachea
C) Alveoli
D) Larynx
E) Pleura
3. The diaphragm is a:
A) Lung lobe
B) Respiratory disease
C) Muscle used for breathing
D) Type of bronchus
E) Gland in the chest
4. Which part of the respiratory system connects the larynx to the bronchi?
A) Nasal cavity
B) Pharynx
C) Trachea
D) Esophagus
E) Epiglottis
5. What protects the lungs and allows them to expand and contract?
A) Bronchi
B) Diaphragm
C) Pleural membrane
D) Pericardium
E) Alveolar sac
6. Which of the following is NOT part of the upper respiratory tract?
A) Nasal cavity
B) Pharynx
C) Larynx
D) Trachea
E) Sinuses
7. The voice box is also known as the:
A) Pharynx
B) Trachea
C) Bronchus
D) Larynx
E) Epiglottis
8. Which gas is removed from the bloodstream during respiration?
A) Nitrogen
B) Oxygen
C) Hydrogen
D) Carbon dioxide
E) Methane
9. Which disorder is characterized by inflammation of the bronchial tubes?
A) Pneumonia
B) Bronchitis
C) Emphysema
D) Asthma
E) Sinusitis
10. Which condition involves destruction of alveoli, reducing gas exchange?
A) Asthma
B) Emphysema
C) Tuberculosis
D) Bronchitis
E) Flu
11. Inhalation occurs when the diaphragm:
A) Relaxes and moves up
B) Contracts and moves down
C) Relaxes and moves down
D) Expands sideways
E) Stays stationary
12. Which of the following helps trap dust and microorganisms in the nasal cavity?
A) Alveoli
B) Mucus and cilia
C) Cartilage
D) Trachea
E) Pleura
13. Which respiratory structure splits into two primary bronchi?
A) Pharynx
B) Larynx
C) Trachea
D) Alveolus
E) Esophagus
14. What is the function of the epiglottis?
A) Produces sound
B) Filters air
C) Warms air
D) Prevents food from entering the airway
E) Produces mucus
15. Which disease is often caused by long-term smoking and leads to reduced lung function?
A) Influenza
B) Bronchitis
C) Emphysema
D) Tuberculosis
E) Tonsillitis
16. Oxygen enters the bloodstream by diffusing through:
A) The diaphragm
B) Capillaries surrounding alveoli
C) The trachea
D) The larynx
E) Bronchi
17. Which of the following best describes asthma?
A) Lung cancer
B) Viral infection
C) Chronic inflammation of airways
D) Bacterial infection of alveoli
E) Blood clot in the lungs
18. What is the role of the nasal conchae?
A) Move the diaphragm
B) Exchange gases
C) Increase surface area for air warming and humidification
D) Trap red blood cells
E) Expand lung capacity
19. Which structure directly connects to the lungs?
A) Esophagus
B) Trachea
C) Pharynx
D) Bronchi
E) Sinuses
20. Which condition is caused by bacterial infection and affects the lungs?
A) Asthma
B) Tuberculosis
C) Emphysema
D) Bronchitis
E) Laryngitis
21. The average number of lobes in the right lung is:
A) One
B) Two
C) Three
D) Four
E) Five
22. What is the name of the fluid that reduces surface tension in the alveoli?
A) Bile
B) Plasma
C) Surfactant
D) Enzyme
E) Mucus
23. Which of the following is an involuntary breathing center in the brain?
A) Cerebellum
B) Hypothalamus
C) Medulla oblongata
D) Thalamus
E) Frontal lobe
24. Hyperventilation results in:
A) Increase in CO₂
B) Decrease in oxygen
C) Decrease in CO₂
D) Increase in hemoglobin
E) Decrease in breathing rate
25. What is the effect of smoking on cilia in the respiratory tract?
A) Increases cilia movement
B) Strengthens alveoli
C) Destroys cilia, reducing defense
D) Stimulates mucus production
E) Increases lung elasticity
26. Where does external respiration occur?
A) Between blood and tissues
B) In the bronchi
C) Between alveoli and blood
D) In mitochondria
E) In muscles
27. Which disease causes fluid accumulation in the alveoli?
A) Asthma
B) Sinusitis
C) Bronchitis
D) Pneumonia
E) COPD
28. What is the function of the pharynx in respiration?
A) Filters air
B) Site of gas exchange
C) Common passageway for air and food
D) Controls breathing rhythm
E) Generates surfactant
29. What is the respiratory rate of a healthy adult at rest?
A) 5–8 breaths/min
B) 10–12 breaths/min
C) 12–20 breaths/min
D) 22–30 breaths/min
E) Over 30 breaths/min
30. Which of these disorders is genetic and leads to thick mucus production?
A) Asthma
B) Tuberculosis
C) Cystic fibrosis
D) Bronchitis
E) Laryngitis
Answers with Explanations
1. C – The main job of the respiratory system is gas exchange: oxygen in, carbon dioxide out.
2. C – Alveoli are tiny sacs where gas exchange with the blood occurs.
3. C – The diaphragm is the major muscle that facilitates breathing.
4. C – The trachea connects the larynx to the bronchi.
5. C – The pleural membranes cover and protect the lungs, aiding expansion.
6. D – The trachea is part of the lower respiratory tract.
7. D – The larynx is commonly called the voice box.
8. D – The body removes carbon dioxide via exhalation.
9. B – Bronchitis is inflammation of the bronchial tubes.
10. B – Emphysema damages alveoli, making gas exchange difficult.
11. B – The diaphragm contracts and flattens during inhalation.
12. B – Mucus traps particles; cilia move them out of the airways.
13. C – The trachea splits into the left and right bronchi.
14. D – The epiglottis covers the trachea during swallowing.
15. C – Emphysema is strongly linked to smoking.
16. B – Oxygen passes from alveoli into surrounding capillaries.
17. C – Asthma is chronic inflammation and narrowing of the airways.
18. C – Nasal conchae warm and humidify incoming air.
19. D – The bronchi lead directly into the lungs.
20. B – Tuberculosis is a bacterial infection affecting lung tissue.
21. C – The right lung has three lobes: superior, middle, and inferior.
22. C – Surfactant reduces surface tension, keeping alveoli open.
23. C – The medulla oblongata regulates involuntary breathing.
24. C – Hyperventilation removes too much CO₂, raising blood pH.
25. C – Smoking damages cilia, making the lungs more vulnerable.
26. C – External respiration is gas exchange between alveoli and blood.
27. D – Pneumonia causes alveoli to fill with fluid, hindering gas exchange.
28. C – The pharynx serves as a shared pathway for air and food.
29. C – A normal adult breathes 12–20 times per minute at rest.
30. C – Cystic fibrosis is a genetic disorder causing thick mucus build-up.
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