Question 1

Which of the following best describes the primary function of surfactant in the alveoli?

Accepted Answer

It reduces surface tension, preventing alveolar collapse and easing breathing movements.

Question 2

A patient accidentally inhales a small object. Based on the anatomy of the bronchi, which bronchus is the object most likely to enter and why?

Accepted Answer

The right primary bronchus, because it is larger in diameter and descends at a steeper angle.

Question 3

Which of the following structures prevents food from entering the trachea during swallowing?

Accepted Answer

Epiglottis

Question 4

A decrease in the production of surfactant would most likely result in which of the following conditions?

Accepted Answer

Collapse of alveoli, known as atelectasis

Question 5

Which equation correctly represents the formation of carbonic acid from carbon dioxide and water in red blood cells?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightarrow H_2CO_3}$$

Question 6

During quiet breathing (eupnea), which muscles are primarily responsible for inspiration?

Accepted Answer

Diaphragm and external intercostal muscles

Question 7

Which of the following best explains why oxygen diffuses from alveolar air into pulmonary capillaries?

Accepted Answer

The partial pressure of oxygen ($$P_{O_2$}) is $$higher in the alveoli than in the blood.

Question 8

A patient with severe emphysema has reduced elastic tissue in the lungs. Which of the following changes would you expect in their pulmonary function?

Accepted Answer

Decreased vital capacity and restricted chest movements

Question 9

Which of the following is the correct definition of tidal volume?

Accepted Answer

The amount of air moved into or out of the lungs during a single quiet breath

Question 10

Which of the following best describes the chloride shift in red blood cells during carbon dioxide transport?

Accepted Answer

Bicarbonate ions move into plasma as chloride ions move into red blood cells to maintain electrical neutrality.

Question 11

Which of the following statements about the respiratory membrane is correct?

Accepted Answer

It consists of the alveolar epithelium, fused basal laminae, and capillary endothelium.

Question 12

A person is exposed to a sudden drop in atmospheric pressure. According to Boyle's Law, what will happen to the volume of their thoracic cavity during inspiration if the pressure outside decreases?

Accepted Answer

The volume of the thoracic cavity will increase, causing air to flow into the lungs.

Question 13

Which of the following is a direct effect of stimulating the carotid and aortic baroreceptors when blood pressure falls?

Accepted Answer

Respiratory rate increases to help restore homeostasis.

Question 14

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

Accepted Answer

It functions in both quiet and forced inspiration.

Question 15

Which of the following equations correctly represents the sum of partial pressures of atmospheric gases according to Dalton's Law?

Accepted Answer

$$P_{N_2$} + P_{O_2$} + P_{CO_2$} + P_{H_2O} = 760\ \mathrm{mmHg}$$

Question 16

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

Accepted Answer

Synthesizing red blood cells

Question 17

A patient with a pneumothorax has air in the pleural cavity. What is the most immediate consequence of this condition?

Accepted Answer

Collapse of the affected lung due to loss of negative pressure

Question 18

Which of the following best explains why the respiratory and cardiovascular systems must coordinate their activities?

Accepted Answer

To ensure efficient gas exchange and maintain homeostatic O$$_2$$ and CO$$_2$$ levels in peripheral tissues

Question 19

Which of the following is the correct definition of compliance in the context of lung physiology?

Accepted Answer

An indicator of the stretch or expandability of the lungs

Chapter 15: The Respiratory System – Structure, Function, and Regulation

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