$$\Delta P = P_{O_2$,\text{alveoli}} - P_{O_2$,\text{capillaries}}$$

Question 1

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

Accepted Answer

Production of hormones for metabolism

Question 2

Which adaptation is shared by all respiratory organs to maximize gas exchange?

Accepted Answer

Moist surfaces for gas dissolution and diffusion

Question 3

In bony fish, what is the main advantage of countercurrent exchange in the gills?

Accepted Answer

It maximizes oxygen diffusion by maintaining a gradient across the entire gill surface.

Question 4

Which equation best represents the relationship between partial pressure and gas diffusion in the lungs?

Accepted Answer

$$\Delta P = P_{O_2$,	ext{alveoli}} - P_{O_2$,	ext{capillaries}}$$

Question 5

Which of the following statements about hemoglobin is correct?

Accepted Answer

Hemoglobin binds oxygen in the lungs and releases it at the body's cells.

Question 6

During inhalation in mammals, which muscles contract to increase thoracic volume?

Accepted Answer

External intercostal muscles and diaphragm

Question 7

A frog uses positive pressure breathing. What does this mean?

Accepted Answer

The frog forces air into its lungs by creating positive pressure in the buccal cavity.

Question 8

What is the main control center for breathing in humans?

Accepted Answer

Medulla oblongata

Question 9

If blood pH drops below 7.4 due to increased CO2, what is the physiological response?

Accepted Answer

Increase in breathing rate and depth

Question 10

Which equation describes the conversion of CO2 to bicarbonate in blood?

Accepted Answer

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

Question 11

Which feature distinguishes lungs from gills in terrestrial animals?

Accepted Answer

Lungs are saclike outpouchings of the gut, while gills are extensions projecting into water.

Question 12

What is the effect of the Bohr shift on hemoglobin's oxygen affinity?

Accepted Answer

Hemoglobin releases more oxygen at lower pH.

Question 13

Which of the following best describes the flow of blood and water in fish gills?

Accepted Answer

Blood and water flow in opposite directions, maximizing oxygen uptake.

Question 14

Which equation represents the oxyhemoglobin dissociation curve at pH 7.4?

Accepted Answer

$$Y = \frac{P_{O_2$}^{n}}{P_{50}^{n} + P_{O_2$}^{n}}$$

Question 15

Which structure is responsible for cleaning the respiratory system by moving particles up to the pharynx?

Accepted Answer

Cilia and mucus lining the air ducts

Question 16

Why must external gills be constantly moved in aquatic animals?

Accepted Answer

To ensure contact with oxygen-rich fresh water

Question 17

Which of the following is a consequence of the pleural cavity being filled with fluid?

Accepted Answer

The two pleural membranes adhere, allowing the lungs to move with the thoracic cavity.

Question 18

During exercise, what happens to the oxyhemoglobin dissociation curve?

Accepted Answer

It shifts to the right, increasing oxygen release to tissues.

Question 19

Which of the following is a real-world consequence of impaired cilia function in the respiratory tract?

Accepted Answer

Accumulation of particles and pathogens, leading to respiratory infections

Question 20

A patient with chronic obstructive pulmonary disease (COPD) has difficulty exhaling. Which muscles are most likely to be affected?

Accepted Answer

Internal intercostal muscles

Ch 34: The Respiratory System: Structure, Function, and Gas Exchange

Study Guide - Practice Questions