$$AV = (Tidal\ Volume\ (TV) - Dead\ Space) \times Respiratory\ Rate$$

Question 1

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

Accepted Answer

It decreases the surface tension of alveolar fluid, preventing alveolar collapse and reducing the work of breathing.

Question 2

A patient with a stab wound to the chest develops a pneumothorax. Which pressure relationship is disrupted, leading to lung collapse?

Accepted Answer

Intrapleural pressure equals atmospheric pressure, eliminating the negative pressure that keeps the lung inflated.

Question 3

According to Boyle’s Law, what happens to the pressure of a gas if the volume of its container is doubled, assuming temperature is constant?

Accepted Answer

The pressure is halved. $$P_1V_1 = P_2V_2$$

Question 4

Which of the following scenarios would most likely result in a rightward shift of the oxygen-hemoglobin dissociation curve?

Accepted Answer

Increased temperature, increased $$P_{CO_2$}$$, and decreased pH

Question 5

A patient with chronic bronchitis is likely to have which of the following changes in pulmonary function test results?

Accepted Answer

Increased residual volume (RV) and increased total lung capacity (TLC)

Question 6

Which equation correctly represents the calculation for alveolar ventilation ($$AV$$)?

Accepted Answer

$$AV = (Tidal\ Volume\ (TV) - Dead\ Space) 	imes Respiratory\ Rate$$

Question 7

Which of the following best explains why patients with emphysema often develop a 'barrel chest' appearance?

Accepted Answer

Destruction of alveolar walls leads to lung hyperinflation, flattening the diaphragm and expanding the chest.

Question 8

Which of the following is the primary factor that determines the direction of gas movement during pulmonary gas exchange?

Accepted Answer

The partial pressure gradient of the gas across the respiratory membrane

Question 9

A person is exposed to carbon monoxide (CO). Why does this result in hypoxemia without the classic signs of cyanosis?

Accepted Answer

CO binds to hemoglobin with a much higher affinity than oxygen, preventing oxygen transport but not changing blood color.

Question 10

Which of the following best describes the Haldane effect?

Accepted Answer

The lower the $$P_{O_2$}$$ and hemoglobin saturation, the more $$CO_2$$ can be carried in the blood.

Question 11

A patient is experiencing an asthma attack. Which of the following best explains the immediate benefit of administering epinephrine?

Accepted Answer

Epinephrine dilates bronchioles, reducing airway resistance and improving airflow.

Question 12

Which of the following is a correct formula for calculating vital capacity (VC)?

Accepted Answer

$$VC = TV + IRV + ERV$$

Question 13

Which of the following best describes the Bohr effect?

Accepted Answer

Increased $$CO_2$$ and decreased pH reduce hemoglobin’s affinity for oxygen, enhancing oxygen unloading in tissues.

Question 14

A patient with left-sided heart failure develops pulmonary edema. How does this affect gas exchange in the lungs?

Accepted Answer

It increases the thickness of the respiratory membrane, slowing diffusion of gases and leading to hypoxemia.

Question 15

Which of the following is the most powerful respiratory stimulant under normal conditions?

Accepted Answer

Increased arterial $$P_{CO_2$}$$

Question 16

Which of the following best explains why rapid, shallow breathing (panting) is less effective for alveolar ventilation than slow, deep breathing?

Accepted Answer

Rapid, shallow breaths increase dead space ventilation, so less fresh air reaches the alveoli.

Question 17

Which of the following is a direct result of the Valsalva maneuver?

Accepted Answer

Increased intra-abdominal pressure to help expel contents from the rectum or stabilize the trunk during heavy lifting.

Question 18

Which of the following best describes the effect of high altitude on the respiratory system?

Accepted Answer

Atmospheric pressure and $$P_{O_2$}$$ are lower, leading to increased ventilation and erythropoietin production.

Question 19

Which of the following is the correct formula for calculating total lung capacity (TLC)?

Accepted Answer

$$TLC = TV + IRV + ERV + RV$$

Chapter 22

Guida di studio - Domande di pratica