Question 1

Which of the following best describes the primary function of alveoli in the respiratory system?

Accepted Answer

To facilitate gas exchange between air and blood due to their thin epithelial walls and extensive capillary network

Question 2

During inspiration, which of the following changes occurs in the thoracic cavity to allow air to flow into the lungs?

Accepted Answer

External intercostal muscles contract, increasing thoracic volume and decreasing alveolar pressure

Question 3

Which equation correctly relates the pressure, volume, and number of moles of a gas in the lungs, assuming constant temperature?

Accepted Answer

$$P V = n R T$$

Question 4

A patient is experiencing hypoventilation. Which of the following changes would you expect in their arterial blood gases?

Accepted Answer

Increased $$CO_2$$ and decreased pH

Question 5

Which of the following mechanisms is responsible for most $$CO_2$$ transport in the blood?

Accepted Answer

Converted to bicarbonate ($$HCO_3$$^-$$) by carbonic anhydrase in red blood cells

Question 6

Hemoglobin’s affinity for oxygen decreases under which of the following conditions?

Accepted Answer

High $$CO_2$$, high temperature, and low pH

Question 7

Which of the following best explains the movement of oxygen from alveoli into pulmonary capillaries?

Accepted Answer

Simple diffusion down its partial pressure gradient

Question 8

A climber at high altitude is exposed to low atmospheric $$O_2$$ pressure. Which physiological response helps maintain adequate oxygen delivery to tissues?

Accepted Answer

Increased production of red blood cells and increased ventilation

Question 9

Which of the following is a direct effect of stimulating central chemoreceptors in the medulla?

Accepted Answer

Increased ventilation rate in response to elevated $$CO_2$$ and decreased pH

Question 10

Which of the following statements about the relationship between partial pressure and gas exchange is correct?

Accepted Answer

The partial pressure gradient drives the diffusion of gases across respiratory membranes

Question 11

A patient with chronic obstructive pulmonary disease (COPD) has impaired gas exchange. Which of the following is most likely to occur?

Accepted Answer

Increased $$CO_2$$ retention and respiratory acidosis

Question 12

Which formula best represents the calculation of minute ventilation ($$V_E$$)?

Accepted Answer

$$V_E = V_T 	imes f$$

Question 13

Which of the following is NOT a function of the mucociliary escalator in the respiratory tract?

Accepted Answer

Humidifying inspired air

Question 14

Which of the following best describes the Bohr effect?

Accepted Answer

Increased $$CO_2$$ and decreased pH reduce hemoglobin’s affinity for oxygen, facilitating oxygen release in tissues

Question 15

Which of the following is the primary stimulus for increased ventilation during exercise?

Accepted Answer

Increased arterial $$CO_2$$ and decreased pH

Question 16

Which of the following best explains why $$O_2 is $$transported in the blood primarily by hemoglobin?

Accepted Answer

Hemoglobin increases the oxygen-carrying capacity of blood far beyond what plasma alone can carry

Question 17

A patient is hyperventilating due to anxiety. What changes would you expect in their blood gas values?

Accepted Answer

Decreased $$CO_2$$ and increased pH (respiratory alkalosis)

Question 18

Which of the following best describes the role of peripheral chemoreceptors in respiratory control?

Accepted Answer

They respond primarily to changes in blood $$O_2$$, $$CO_2$$, and pH

Question 19

Which of the following equations correctly represents the conversion of $$CO_2 to $$bicarbonate in red blood cells?

Accepted Answer

$$CO_2 + H_2O$$ \rightarrow H_2CO_3 \rightarrow H^+ + $$HCO_3$$^-$$

Question 20

Which of the following factors would most likely increase the rate of diffusion of oxygen across the alveolar membrane?

Accepted Answer

Increased partial pressure gradient of $$O_2$$ between alveoli and blood

Mechanisms of Breathing, Gas Exchange, and Transport: Study Guide Notes

Study Guide - Practice Questions

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