Q: Given atmospheric pressure is 760 mmHg and the fractional concentration of oxygen in air is 0.2093, what is the partial pressure of oxygen ($$P_{O_2$}) in $$dry atmospheric air?

$$P_{O_2$} = 760 \times 0.2093 = 159.07$$ mmHg

Question 1

A scuba diver ascends rapidly from deep water, risking 'the bends.' Which gas law explains why nitrogen bubbles form in the blood during this process?

Accepted Answer

Dalton's Law of Partial Pressures

Question 2

Given atmospheric pressure is 760 mmHg and the fractional concentration of oxygen in air is 0.2093, what is the partial pressure of oxygen ($$P_{O_2$}) in $$dry atmospheric air?

Accepted Answer

$$P_{O_2$} = 760 	imes 0.2093 = 159.07$$ mmHg

Question 3

Which of the following best describes the relationship between partial pressure and concentration of a gas in a liquid?

Accepted Answer

The concentration of a gas in a liquid is dependent on both its partial pressure and its solubility in that liquid.

Question 4

At equilibrium, the partial pressure of oxygen in air and water is equal, but the concentration is not. Why?

Accepted Answer

The solubility of oxygen in water is much lower than in air, so its concentration in water is less.

Question 5

Which equation represents Dalton’s Law of Partial Pressures?

Accepted Answer

$$P_{total} = P_1$ + P_2$ + P_3$ + ... + P_n$$

Question 6

Why is the concentration of CO2 in water higher than O2 at the same partial pressure?

Accepted Answer

CO2 is 20 times more soluble in water than O2.

Question 7

A patient in a hyperbaric chamber is exposed to increased atmospheric pressure. What effect does this have on gas solubility in their blood?

Accepted Answer

Gas solubility increases as pressure increases.

Question 8

Which term describes a temporary cessation of breathing?

Accepted Answer

Apnea

Question 9

If alveolar ventilation increases without a change in oxygen consumption, what happens to alveolar $$P_{O_2$}$$ and $$P_{CO_2$}$$?

Accepted Answer

Alveolar $$P_{O_2$}$$ increases and $$P_{CO_2$}$$ decreases.

Question 10

Which of the following is the main buffer system for maintaining acid-base homeostasis in the blood?

Accepted Answer

Hemoglobin and bicarbonate ions

Question 11

What is the effect of increased temperature on hemoglobin’s affinity for oxygen, as shown by the oxyhemoglobin dissociation curve?

Accepted Answer

Curve shifts right, affinity decreases

Question 12

A patient is hyperventilating. What is the expected effect on blood pH?

Accepted Answer

Blood pH increases, causing alkalosis

Question 13

Which formula is used to calculate blood pH using the Henderson-Hasselbalch equation?

Accepted Answer

$$pH = 6.1 + \log \left( \frac{[$$HCO_3$$^-]}{[CO_2$]} \right)$$

Question 14

Which term describes an excess of carbon dioxide in the blood?

Accepted Answer

Hypercapnia

Question 15

What is the effect of a leftward shift in the oxyhemoglobin dissociation curve?

Accepted Answer

Hemoglobin has increased affinity for oxygen

Question 16

Which physiological response occurs when arterial $$P_{CO_2$}$$ rises above normal?

Accepted Answer

Ventilation increases

Question 17

If a patient has a deficiency of oxygen in the tissues, which term best describes this condition?

Accepted Answer

Hypoxia

Question 18

Which of the following best explains why hemoglobin releases more oxygen in tissues with high $$P_{CO_2$}$$ and low pH?

Accepted Answer

The Bohr effect

Question 19

What is the primary mechanism for CO2 transport in the blood?

Accepted Answer

Converted to bicarbonate ions ($$HCO_3$$^-$$) in plasma

Question 20

A patient with hypoventilation is likely to develop which acid-base disturbance?

Accepted Answer

Respiratory acidosis

Gas Exchange and Breathing: Pulmonary Ventilation, Gas Transport, and Regulation

Study Guide - Practice Questions

Study Guide - Flashcards