1. What is the primary function of the respiratory system in humans?
a. Transportation of nutrients
b. Gas exchange
c. Circulation of blood
d. Synthesis of hormones
Answer: b. Gas exchange
2. Which respiratory structure in humans is responsible for the exchange of gases between the air and the blood?
a. Alveoli
b. Bronchi
c. Trachea
d. Larynx
Answer: a. Alveoli
3. During inhalation, the diaphragm contracts and moves downward. What happens to the volume and pressure in the thoracic cavity?
a. Volume increases, pressure increases
b. Volume decreases, pressure increases
c. Volume increases, pressure decreases
d. Volume decreases, pressure decreases
Answer: c. Volume increases, pressure decreases
4. Which gas is transported by hemoglobin in red blood cells?
a. Carbon dioxide
b. Nitrogen
c. Oxygen
d. Hydrogen
Answer: c. Oxygen
5. What is the term for the process of the exchange of gases between the lungs and the blood?
a. Respiration
b. Inspiration
c. Exhalation
d. Ventilation
Answer: a. Respiration
6. What is the role of surfactant in the lungs?
a. Increases surface tension
b. Prevents collapse of alveoli
c. Promotes oxygen binding to hemoglobin
d. Initiates the cough reflex
Answer: b. Prevents collapse of alveoli
7. Which respiratory disorder is characterized by the inflammation and narrowing of the airways, leading to difficulty in breathing?
a. Asthma
b. Emphysema
c. Pneumonia
d. Tuberculosis
Answer: a. Asthma
8. During cellular respiration, which gas is produced as a byproduct and needs to be removed from the body?
a. Oxygen
b. Nitrogen
c. Carbon dioxide
d. Hydrogen
Answer: c. Carbon dioxide
9. What is the primary muscle responsible for normal expiration (exhalation) at rest?
a. Diaphragm
b. External intercostal muscles
c. Internal intercostal muscles
d. Abdominal muscles
Answer: a. Diaphragm
10. The enzyme carbonic anhydrase plays a crucial role in the transport of carbon dioxide in the blood by converting it into:
a. Bicarbonate ions
b. Oxygen
c. Nitrogen gas
d. Hydrogen ions
Answer: a. Bicarbonate ions
11. Which of the following respiratory structures is lined with cilia and mucus to trap and remove dust particles and pathogens?
a. Trachea
b. Bronchioles
c. Alveoli
d. Pharynx
Answer: a. Trachea
12. What is the term for the amount of air inspired and expired during normal breathing at rest?
a. Inspiratory reserve volume (IRV)
b. Tidal volume (TV)
c. Expiratory reserve volume (ERV)
d. Residual volume (RV)
Answer: b. Tidal volume (TV)
13. During intense physical activity, which respiratory parameter increases to meet the demand for oxygen supply to the tissues?
a. Tidal volume (TV)
b. Inspiratory reserve volume (IRV)
c. Expiratory reserve volume (ERV)
d. Respiratory rate
Answer: d. Respiratory rate
14. Which gas is a component of the atmosphere but does not participate in gas exchange during respiration in humans?
a. Oxygen
b. Carbon dioxide
c. Nitrogen
d. Hydrogen
Answer: c. Nitrogen
15. What is the primary stimulus for increasing the rate and depth of breathing in response to low oxygen levels in the blood?
a. Increased carbon dioxide levels
b. Decreased carbon dioxide levels
c. Increased oxygen levels
d. Decreased oxygen levels
Answer: d. Decreased oxygen levels
16. Which respiratory disorder is characterized by the destruction of the walls of the alveoli, leading to reduced surface area for gas exchange?
a. Asthma
b. Emphysema
c. Bronchitis
d. Pneumonia
Answer: b. Emphysema
17. During cellular respiration, glucose is oxidized, producing carbon dioxide and:
a. Oxygen
b. Water
c. Nitrogen
d. Methane
Answer: b. Water
18. Which part of the brain is responsible for regulating the basic rhythm and depth of breathing?
a. Cerebrum
b. Medulla oblongata
c. Cerebellum
d. Pons
Answer: b. Medulla oblongata
19. In what form is most of the oxygen transported in the blood?
a. Dissolved in plasma
b. Bound to hemoglobin
c. As bicarbonate ions
d. Combined with nitrogen
Answer: b. Bound to hemoglobin
20. What is the purpose of the Bohr effect in the context of oxygen transport in the blood?
a. Enhances oxygen binding to hemoglobin in the lungs
b. Promotes oxygen release to tissues in the presence of carbon dioxide
c. Increases carbon dioxide concentration in the blood
d. Inhibits oxygen transport in the blood
Answer: b. Promotes oxygen release to tissues in the presence of carbon dioxide
21. In humans, what is true about RBCs?
1. They transport about 80% of oxygen, and the remaining 20% is dissolved in blood plasma.
2. They transport 99.5% of oxygen
3. About 20-25% of CO2 is carried by them
4. They do not hold CO2
Answer – 2, They transport 99.5% of oxygen
22. Pick the incorrect statement
1. A bird’s ability to breathe efficiently is enhanced by the presence of non-respiratory air sacs.
2. Having residual air in the lungs slightly reduces the efficiency of respiration in mammals.
3. Fishes use counter-current flow to facilitate efficient respiration.
4. In insects, circulating body fluids help distribute oxygen to the tissues.
Answer – 2, Having residual air in the lungs slightly reduces the efficiency of respiration in mammals.
23. Why does oxygen move through the alveolar blood capillaries of the lungs?
1. Differences in the O2 tension and partial pressure of these chambers
2. The partial pressure of CO2
3. Union of O2 with hemoglobin
4. All of the above
Answer – 4, All of the above
24. Partial Pressure of oxygen is equal to
1. Deoxygenated Blood and tissues
2. Alveoli and Oxygenated Blood
3. Alveoli and Deoxygenated Blood
4. Air and Alveoli
Answer – 2, Alveoli and Oxygenated Blood
25. A person living at sea level has approximately 5 million red blood cells per cubic millimeter of blood. In comparison, a person living at 5400 meters has about 8 million red blood cells. Because of the high altitude
1. Low O2 content in the atmosphere requires more red blood cells to absorb the O2 amount needed for survival.
2. more UV light and increased red blood cell production;
3. people eat more nutritious food, so more red blood cells are formed
4. people are pollution-free-breathing air, and more oxygen available
Answer – 2, UV light and increased red blood cell production
26. An increase in lung ventilation rate is caused by which of the following conditions?
1. Increase of CO2 content in inhaled air
2. Addition of CO2 content in exhaled air
3. Decrease of O2 content in exhaled air
4. Reduction of O2 content in inhaled air
Answer – 1, Increase of CO2 content in inhaled air
27. Haemoglobin is bonded to carbon monoxide and, therefore cannot transport oxygen is called
1. Carboxyhaemoglobin
2. Reduced hemoglobin
3. Carbamino Haemoglobin
4. Methemoglobin
Answer – 1, Carboxyhaemoglobin
28. What diseases can occur when the hemoglobin concentration in the blood is low?
1. Pleurisy
2. Emphysema
3. Anemia
4. pneumonia
Answer- 3, Anemia
29. Mark incorrect statements about respiratory system function.
1. Humidify the air
2. warm the air
3. Diffusion of gas
4. purify the air
Answer – 4, purify the air
30. Among the following which is made up of cartilage
1. Larynx
2. Pharynx
3. Cartilage
4. Trachea
Answer – 4, trachea
31. What happens to the respiratory rate when the carbon dioxide concentration in the blood increases?
1. remain unaffected;
2. decrease
3. stop
4. increase
Answer- 4, increase
32. When blood carbon dioxide levels rise, what happens to breathing?
What if the concentration of O2 in the tissues is high near the respiratory surface?
1. oxyhemoglobin dissociates to supply O2 to tissues
2. hemoglobin will combine with more O2 for tissues
3. oxyhemoglobin will not dissociate to provide O2 to tissues
4. CO2 will interfere with O2 transport.
Answer – 3, hemoglobin will combine with more O2 for tissues
33. Where does the motivation for voluntary forced breathing come from?
1. marrow
2. vagus nerve
3. spinal cord
4. Brain
Answer – 4, brain
34. What if human blood becomes acidic (low pH)?
1. The oxygen-carrying capacity of hemoglobin is reduced
2. The oxygen-carrying capacity of hemoglobin is increased
3. Increased red blood cell count
4. Decreased red blood cell count
Answer – 1, The oxygen-carrying capacity of hemoglobin is reduced
35. Does the polluted air contain unusually high concentrations inhaled by the patient?
1. carbon disulfide
2. chloroform
3. carbon dioxide
4. carbon monoxide gas
Answer – 4, carbon monoxide gas
36. C02 in the blood lowers the pH because C02 combines with ______, and the reaction rate increases ______.
1. H2O to form H+ and HCO3-, carbonic anhydrase
2. H2O forms only HCO3-, carbonic anhydrase
3. H2O only forms H+ ions, carbon
4. H+ to form HCO3-, oxyhemoglobin
Answer – 1, H2O to form H+ and HCO3-, carbonic anhydrase