Q: Which equation correctly represents the relationship between airflow, pressure, and resistance in the respiratory system?

$$F = \\frac{P_{ATM} - P_{ALV}}{R}$$

Q: Calculate the partial pressure of oxygen ($$P_{O_2$}) at $$sea level if atmospheric pressure is 760 mmHg and oxygen makes up 21% of the air.

$$P_{O_2$} = 0.21 \\times 760 = 159.6 \\text{ mmHg}$$

Question 1

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

Accepted Answer

To serve as the main site of gas exchange between air and blood

Question 2

A patient with pulmonary fibrosis has decreased lung compliance. Which of the following best explains this condition?

Accepted Answer

The lungs resist expansion due to scarred tissue, requiring more effort to inflate

Question 3

According to Boyle’s Law, what happens to the pressure inside the lungs when the volume of the thoracic cavity increases during inhalation?

Accepted Answer

Pressure decreases, causing air to flow into the lungs

Question 4

A premature infant is diagnosed with respiratory distress syndrome due to insufficient surfactant. What is the physiological consequence of this deficiency?

Accepted Answer

Increased surface tension in the alveoli, leading to alveolar collapse

Question 5

Which equation correctly represents the relationship between airflow, pressure, and resistance in the respiratory system?

Accepted Answer

$$F = \frac{P_{ATM} - P_{ALV}}{R}$$

Question 6

A scuba diver ascends too quickly and develops decompression sickness. According to Henry’s Law, what is the cause of this condition?

Accepted Answer

Nitrogen rapidly leaves the blood, forming gas bubbles in tissues

Question 7

Calculate the partial pressure of oxygen ($$P_{O_2$}) at $$sea level if atmospheric pressure is 760 mmHg and oxygen makes up 21% of the air.

Accepted Answer

$$P_{O_2$} = 0.21 \times 760 = 159.6 \text{ mmHg}$$

Question 8

Which of the following factors would most likely decrease the rate of gas exchange across the respiratory membrane?

Accepted Answer

Fluid accumulation in the interstitial space

Question 9

During exercise, the affinity of hemoglobin for oxygen decreases. Which of the following factors contributes to this effect?

Accepted Answer

Increased acidity (lower pH) in muscle tissue

Question 10

Which of the following best describes the Bohr effect?

Accepted Answer

Decreased affinity of hemoglobin for oxygen in the presence of increased CO2 or acidity

Question 11

A patient with emphysema has increased lung compliance. What is the main physiological change in their lungs?

Accepted Answer

Destruction of elastic fibers, making the lungs inflate easily but recoil poorly

Question 12

Which of the following is the primary muscle responsible for quiet inhalation?

Accepted Answer

Diaphragm

Question 13

Which of the following statements about the transport of carbon dioxide in the blood is correct?

Accepted Answer

Most CO2 is transported as bicarbonate ions ($$HCO_3$$^-$$) in plasma

Question 14

Which of the following best explains why nitrogen does not significantly exchange with blood at sea level?

Accepted Answer

Nitrogen is not very soluble in blood at sea level

Question 15

Which of the following is a function of the mucous membrane lining the respiratory tract?

Accepted Answer

To move mucus and trapped particles toward the pharynx via cilia

Question 16

A swimmer hyperventilates before a long dive. What is the physiological advantage of this behavior?

Accepted Answer

It decreases blood PCO2, delaying the urge to breathe

Question 17

Which of the following best describes the role of the pleural cavity in ventilation?

Accepted Answer

It mechanically couples the lungs to the chest wall, allowing both to move together

Question 18

Which of the following is true regarding the conducting zone of the respiratory system?

Accepted Answer

It includes the nose, pharynx, larynx, trachea, bronchi, and terminal bronchioles

Question 19

Which of the following best explains why outward diffusion of CO2 is faster than inward diffusion of O2 across the respiratory membrane?

Accepted Answer

CO2 is more soluble in plasma than O2

The Respiratory System: Structure, Function, and Physiology

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