Quiz on the Respiratory System
Multiple Choice Questions
1. What is the main purpose of the respiratory system?
A) To circulate blood
B) To digest food
C) To exchange gases
D) To regulate body temperature
E) To produce hormones
2. Which structure is primarily responsible for gas exchange in the lungs?
A) Bronchi
B) Alveoli
C) Trachea
D) Diaphragm
E) Larynx
3. What happens to the diaphragm when you inhale?
A) It relaxes and moves up
B) It contracts and moves down
C) It stays the same
D) It expands and moves outwards
E) It tightens and moves sideways
4. Which of the following is NOT a part of the respiratory system?
A) Nose
B) Lungs
C) Heart
D) Trachea
E) Bronchi
5. How does oxygen enter the bloodstream?
A) Through the skin
B) From the stomach
C) By diffusion in the alveoli
D) Through the blood vessels
E) By being swallowed
6. What is the role of cilia in the respiratory system?
A) To produce mucus
B) To filter and move particles out of the airways
C) To help with gas exchange
D) To expand the lungs
E) To absorb oxygen
7. Which gas is primarily expelled from the body during exhalation?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Helium
E) Hydrogen
8. What is the function of the alveoli?
A) To warm the air
B) To humidify the air
C) To provide a surface for gas exchange
D) To produce sound
E) To filter dust
9. What is the pathway of air through the respiratory system?
A) Nose → Trachea → Bronchi → Alveoli
B) Mouth → Lungs → Diaphragm → Heart
C) Nose → Lungs → Alveoli → Blood
D) Trachea → Alveoli → Nose → Bronchi
E) Mouth → Trachea → Alveoli → Blood
10. Why is it important for the alveoli to have a large surface area?
A) To increase air pressure
B) To enhance gas exchange efficiency
C) To store oxygen
D) To protect against infection
E) To cool the air
11. What happens to the rib cage during inhalation?
A) It contracts
B) It expands
C) It stays the same
D) It sinks
E) It twists
12. Which of the following statements about the respiratory system is true?
A) It only works when you are awake
B) It is not involved in the digestive process
C) It does not require energy
D) It only exchanges gases during exercise
E) It is the same as the circulatory system
13. How does smoking affect the respiratory system?
A) It improves lung capacity
B) It increases the number of alveoli
C) It damages the cilia and alveoli
D) It has no effect
E) It strengthens the diaphragm
14. What is the role of the pleura in the respiratory system?
A) To produce mucus
B) To protect the lungs and allow movement
C) To filter air
D) To exchange gases
E) To regulate blood flow
15. Which part of the brain controls the breathing process?
A) Cerebellum
B) Medulla oblongata
C) Cerebrum
D) Brainstem
E) Hypothalamus
16. What is the effect of exercise on the respiratory system?
A) It decreases breathing rate
B) It increases oxygen demand and breathing rate
C) It has no effect
D) It causes lung damage
E) It reduces lung capacity
17. Which of the following best describes the process of inhalation?
A) Diaphragm relaxes, air is pushed out
B) Diaphragm contracts, air is drawn in
C) Rib cage collapses, air is expelled
D) Alveoli fill with carbon dioxide
E) Lungs shrink, air is absorbed
18. What is the function of the trachea?
A) To filter and humidify air
B) To exchange gases
C) To produce sound
D) To store air
E) To connect the lungs to the heart
19. Which of the following is a common respiratory condition?
A) Diabetes
B) Asthma
C) Hypertension
D) Arthritis
E) Osteoporosis
20. What is the primary component of the air we breathe?
A) Carbon dioxide
B) Oxygen
C) Nitrogen
D) Hydrogen
E) Argon
