Question 1

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

Accepted Answer

To facilitate the exchange of oxygen and carbon dioxide between the atmosphere and the blood

Question 2

Which structure prevents food and liquids from entering the lower respiratory tract during swallowing?

Accepted Answer

Epiglottis

Question 3

According to Boyle’s Law, what happens to the pressure inside the lungs if the volume of the thoracic cavity increases, assuming temperature and number of gas molecules remain constant?

Accepted Answer

Pressure decreases

Question 4

A patient with a thickened respiratory membrane due to pulmonary fibrosis will most likely experience which of the following?

Accepted Answer

Decreased efficiency of gas exchange

Question 5

Which law explains why oxygen diffuses from the alveoli into the blood, and carbon dioxide diffuses from the blood into the alveoli?

Accepted Answer

Dalton’s Law of Partial Pressures

Question 6

A person is exposed to high levels of carbon monoxide (CO). Which of the following best explains why this is dangerous?

Accepted Answer

CO binds to hemoglobin with a much higher affinity than oxygen, reducing oxygen transport

Question 7

Which of the following changes would most likely increase the affinity of hemoglobin for oxygen?

Accepted Answer

Decreased PCO2

Question 8

A patient is experiencing hypoventilation. What is the expected effect on blood pH, and why?

Accepted Answer

Blood pH decreases due to increased CO2

Question 9

Which of the following is a direct result of surfactant secretion in the alveoli?

Accepted Answer

Decreased alveolar surface tension

Question 10

A person at high altitude produces more 2,3-bisphosphoglycerate (BPG). What is the physiological significance of this adaptation?

Accepted Answer

BPG decreases hemoglobin’s affinity for oxygen, enhancing unloading in tissues

Question 11

Which of the following best describes the effect of bronchoconstriction on airway resistance and airflow?

Accepted Answer

Increases airway resistance and decreases airflow

Question 12

A patient with chronic bronchitis is likely to have which of the following changes in their respiratory system?

Accepted Answer

Increased mucus production and paralysis of cilia

Question 13

Which of the following equations correctly represents the carbonic acid-bicarbonate buffer system in the blood?

Accepted Answer

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

Question 14

Which of the following is the main muscle responsible for quiet inspiration?

Accepted Answer

Diaphragm

Question 15

If intrapleural pressure becomes equal to or greater than atmospheric pressure, what is the most likely consequence?

Accepted Answer

Lungs will collapse

Question 16

Which of the following best explains why a person with emphysema has difficulty with gas exchange?

Accepted Answer

Destruction of alveolar walls reduces surface area for gas exchange

Question 17

Which of the following is the correct sequence of airflow from the external environment to the alveoli?

Accepted Answer

Nares → Nasal cavity → Pharynx → Larynx → Trachea → Primary bronchi → Secondary bronchi → Tertiary bronchi → Bronchioles → Terminal bronchioles → Respiratory bronchioles → Alveolar ducts → Alveolar sacs

Question 18

Which of the following best describes the Bohr effect?

Accepted Answer

Increased acidity and PCO2 decrease hemoglobin’s affinity for oxygen, promoting oxygen unloading in tissues

Question 19

Which of the following is a function of the respiratory system that assists with cardiovascular homeostasis?

Accepted Answer

Synthesis of angiotensin-converting enzyme (ACE) for production of angiotensin-II

Question 20

A patient with asthma experiences bronchoconstriction, airway inflammation, and increased mucus production after exposure to pollen. Which of the following best explains the resulting change in airway resistance?

Accepted Answer

Airway resistance increases, making expiration more difficult

Chapter 21: The Respiratory System – Structure, Function, and Physiology

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