Question 1

Which structure in the lower respiratory tract is primarily responsible for gas exchange with the blood?

Accepted Answer

Alveoli

Question 2

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

Accepted Answer

The intercostal muscles contract, elevating the chest wall

Question 3

Which equation best represents the relationship between pressure, volume, and breathing according to Boyle’s Law?

Accepted Answer

$$P_1$$ $$V_1$$ = $$P_2$$ $$V_2$$

Question 4

A patient with emphysema is likely to have which of the following changes in lung volumes?

Accepted Answer

Decreased vital capacity

Question 5

Which of the following is the main mechanism by which carbon dioxide is transported in the blood?

Accepted Answer

As plasma bicarbonate

Question 6

What is the function of the pleural membranes in the respiratory system?

Accepted Answer

To reduce friction between the lungs and thoracic cavity during breathing

Question 7

Which of the following best describes the role of the medulla oblongata in breathing?

Accepted Answer

It establishes the basic breathing pattern

Question 8

If a person forcibly exhales as much air as possible after a normal exhalation, which lung volume is being measured?

Accepted Answer

Expiratory reserve volume

Question 9

Which of the following is NOT a function of the upper respiratory tract?

Accepted Answer

Gas exchange with blood

Question 10

A person with cystic fibrosis has thick mucus in the lungs. Which process is most directly impaired?

Accepted Answer

External respiration

Question 11

Which chemical equation represents the conversion of carbon dioxide to bicarbonate in the blood?

Accepted Answer

$$\mathrm{CO_2$} + \mathrm{H_2O} \rightarrow \mathrm{H_2CO_3} \rightarrow \mathrm{$$HCO_3$$^-} + \mathrm{H^+}$$

Question 12

Which of the following scenarios would most likely trigger the cough reflex?

Accepted Answer

Contraction of smooth muscle decreasing tracheal diameter

Question 13

Which of the following best explains why oxygen diffuses from alveoli into capillaries?

Accepted Answer

Partial pressure of oxygen is higher in alveoli than in capillaries

Question 14

Which of the following is the correct sequence for the passage of air from the nose to the alveoli?

Accepted Answer

Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

Question 15

Which of the following is most likely to occur if the pH of cerebrospinal fluid decreases?

Accepted Answer

Breathing rate increases

Question 16

A spirometer is used to measure which of the following?

Accepted Answer

Lung volumes and vital capacity

Question 17

Which of the following is a real-life consequence of impaired external respiration?

Accepted Answer

Decreased oxygen delivery to tissues

Question 18

Which of the following best describes the role of hemoglobin in oxygen transport?

Accepted Answer

Hemoglobin binds to oxygen, increasing its solubility in blood

Question 19

Which of the following is a plausible outcome of damage to the vocal cords?

Accepted Answer

Difficulty in sound production

Question 20

Which of the following disorders is characterized by reduced air flow due to constriction of bronchioles?

Accepted Answer

Asthma

The Human Respiratory System: Structure, Function, and Gas Exchange

Study Guide - Practice Questions