Q: According to Dalton’s Law, what is the partial pressure of oxygen ($$P_{O_2$}) in $$atmospheric air at sea level (760 mmHg) if oxygen makes up 20.9% of the atmosphere?

$$P_{O_2$} = 0.209 \times 760 = 159$$ mmHg

Question 1

Which of the following structures is the primary site for gas exchange in the lungs?

Accepted Answer

Alveoli

Question 2

A patient with a mutation that prevents the production of surfactant would most likely experience which of the following problems?

Accepted Answer

Collapse of alveoli during exhalation

Question 3

According to Boyle’s Law, what happens to the pressure inside the lungs if the volume of the thoracic cavity increases?

Accepted Answer

Pressure decreases

Question 4

Which of the following equations correctly represents Boyle’s Law as it applies to pulmonary ventilation?

Accepted Answer

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

Question 5

Which of the following best describes the function of the epiglottis during swallowing?

Accepted Answer

It prevents food and liquids from entering the respiratory tract

Question 6

A person inhales deeply and then forcibly exhales as much air as possible. Which muscles are primarily responsible for this forced exhalation?

Accepted Answer

Internal intercostals and abdominal muscles

Question 7

Which of the following statements about the conducting zone of the respiratory system is correct?

Accepted Answer

It includes the nasal cavity, pharynx, larynx, trachea, bronchi, and terminal bronchioles

Question 8

A patient with asthma experiences bronchoconstriction and mucus accumulation. How does this affect airway resistance and airflow?

Accepted Answer

Resistance increases, airflow decreases

Question 9

Which of the following best explains why oxygen is transported primarily by hemoglobin in the blood?

Accepted Answer

Oxygen is not soluble enough in plasma to meet tissue needs

Question 10

According to Dalton’s Law, what is the partial pressure of oxygen ($$P_{O_2$}) in $$atmospheric air at sea level (760 mmHg) if oxygen makes up 20.9% of the atmosphere?

Accepted Answer

$$P_{O_2$} = 0.209 	imes 760 = 159$$ mmHg

Question 11

Which of the following changes would most likely shift the hemoglobin-oxygen saturation curve to the right, resulting in more oxygen being released to tissues?

Accepted Answer

Increased pCO2 and decreased pH

Question 12

A patient is experiencing hypoventilation. What effect would this have on blood pCO2 and the activity of chemoreceptors?

Accepted Answer

Blood pCO2 increases, chemoreceptor activity increases

Question 13

Which of the following best describes the chloride shift that occurs in red blood cells during carbon dioxide transport?

Accepted Answer

Chloride ions move into RBCs as bicarbonate ions move out

Question 14

Which of the following is a function of the nasal conchae in the upper respiratory tract?

Accepted Answer

They cause turbulent airflow to increase warming, humidification, and particle trapping

Question 15

A patient with a pneumothorax has air in the pleural cavity. What is the most likely consequence for the affected lung?

Accepted Answer

The lung will collapse due to loss of negative intrapleural pressure

Question 16

Which of the following best describes the role of the dorsal respiratory group (DRG) in the medulla oblongata?

Accepted Answer

It stimulates inspiratory muscles during quiet and forced breathing

Question 17

Which of the following would most likely decrease lung compliance?

Accepted Answer

Fibrosis (stiffening of lung connective tissue)

Question 18

During exercise, active tissues generate more CO2 and become more acidic. How does this affect oxygen delivery?

Accepted Answer

Hemoglobin releases more oxygen to the tissues

Question 19

Which of the following is a characteristic of the respiratory membrane that allows for efficient gas exchange?

Accepted Answer

It is approximately 0.5 µm thick, allowing rapid diffusion

Question 20

Which of the following best explains why a person cannot voluntarily hold their breath until death?

Accepted Answer

Rising pCO2 levels trigger involuntary reflexes that force breathing

The Respiratory System: Structure, Function, and Physiology

Study Guide - Practice Questions

Study Guide - Flashcards