Question 1

Which of the following best explains why the tracheal cartilages are C-shaped rather than complete rings?

Accepted Answer

To provide flexibility and allow the esophagus to expand posteriorly when swallowing food.

Question 2

A patient with cystic fibrosis experiences frequent respiratory infections and difficulty breathing. Which aspect of the respiratory mucosa is most directly responsible for these symptoms?

Accepted Answer

The presence of thick, sticky mucus that impairs ciliary function and traps pathogens.

Question 3

During an asthma attack, which physiological change occurs in the bronchioles?

Accepted Answer

Bronchoconstriction and inflammation, leading to restricted airflow.

Question 4

Which of the following best describes the movement of gases during external respiration?

Accepted Answer

Oxygen moves from the alveoli into the capillaries, and carbon dioxide moves from the capillaries into the alveoli.

Question 5

A person is stabbed in the chest, causing air to enter the pleural cavity. What is the most likely consequence?

Accepted Answer

Atelectasis, or collapse of the affected lung, due to loss of the bond between visceral and parietal pleura.

Question 6

Which equation correctly represents the conversion of carbon dioxide to bicarbonate in the blood?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightarrow H_2CO_3 \rightarrow H^+ + $$HCO_3$$^-}$$

Question 7

Which of the following is NOT a function of the respiratory mucosa?

Accepted Answer

Facilitating gas exchange between alveoli and capillaries.

Question 8

A patient is experiencing hypoventilation. What change in blood gases would you expect, and how would the body respond?

Accepted Answer

Increased arterial $$\mathrm{CO_2$} ($$hypercapnia), stimulating chemoreceptors to increase respiratory rate.

Question 9

Which of the following best explains why surfactant is essential for normal lung function?

Accepted Answer

It reduces surface tension in the alveoli, preventing their collapse during exhalation.

Question 10

Which of the following pulmonary volumes represents the maximum amount of air a person can move in or out of the lungs in a single respiratory cycle?

Accepted Answer

Vital capacity

Question 11

A 60-year-old smoker presents with chronic cough, overproduction of mucus, and bluish skin. Which condition is most likely?

Accepted Answer

Chronic bronchitis ("blue bloater")

Question 12

Which of the following best describes the role of hemoglobin in oxygen transport?

Accepted Answer

Hemoglobin binds oxygen in the pulmonary capillaries and releases it in the systemic capillaries.

Question 13

Which muscles are primarily responsible for quiet inhalation during normal breathing?

Accepted Answer

Diaphragm and external intercostals

Question 14

Which of the following best explains why hyperventilating before swimming underwater can lead to shallow water blackout?

Accepted Answer

Hyperventilation decreases blood carbon dioxide levels, delaying the urge to breathe until oxygen is dangerously low.

Question 15

Which of the following is a correct sequence of airflow through the respiratory tract from the external environment to the alveoli?

Accepted Answer

Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

Question 16

Which of the following best describes the effect of aging on the respiratory system?

Accepted Answer

Decreased elasticity and flexibility of connective tissues, leading to reduced respiratory performance.

Question 17

Which of the following equations represents the release of oxygen from hemoglobin in systemic capillaries?

Accepted Answer

$$\mathrm{$$HbO_2$$ \rightarrow Hb + O_2$}$$

Question 18

Which of the following is a major risk factor for developing lung cancer?

Accepted Answer

Cigarette smoking, including exposure to secondhand smoke

Question 19

Which of the following best describes the function of the dorsal respiratory group (DRG) in the medulla oblongata?

Accepted Answer

It acts as the inspiratory center, controlling the diaphragm and external intercostals during every respiratory cycle.

Question 20

A person inhales deeply using accessory inspiratory muscles. Which muscles are involved in this process?

Accepted Answer

Sternocleidomastoid, scalenes, and pectoralis minor

The Respiratory System: Structure, Function, and Disorders

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