Respiratory system

Question 1

Which structure serves as the primary site for gas exchange in the respiratory system?
A. Trachea
B. Bronchi
C. Alveoli
D. Larynx

Answer 1

C. Alveoli

The alveoli are tiny air sacs in the lungs where oxygen and carbon dioxide exchange occurs between the lungs and capillaries. The trachea and bronchi serve as conducting passages, while the larynx is involved in phonation and airway protection

Question 2

Which of the following structures prevents food from entering the trachea during swallowing?
A. Uvula
B. Epiglottis
C. Larynx
D. Vocal cords

Answer 2

B. Epiglottis

The epiglottis is a flap of cartilage that covers the glottis (opening of the trachea) when swallowing, preventing food and liquids from entering the airway. Dysfunction can result in aspiration and an increased risk of pneumonia.

Question 3

What is the function of the cilia-mucus escalator in the respiratory tract?
A. To increase oxygen absorption
B. To move mucus and trapped particles out of the airways
C. To humidify inhaled air
D. To produce surfactant

Answer 3

B. To move mucus and trapped particles out of the airways

The cilia-mucus escalator consists of cilia-lined epithelial cells that continuously move mucus and trapped debris up the trachea toward the pharynx, where it can be swallowed or expelled. This mechanism is impaired in smokers, increasing the risk of respiratory infections.

Question 4

What is the role of alveolar macrophages in lung defense?
A. They produce surfactant
B. They destroy pathogens and debris
C. They increase oxygen diffusion
D. They maintain pleural pressure

Answer 4

B. They destroy pathogens and debris

Alveolar macrophages, also called dust cells, are immune cells in the alveoli that phagocytise (engulf and digest) bacteria, dust, and dead cells to keep the alveoli clear. A weakened immune system or chronic smoking can impair their function, leading to lung infections.

Question 5

What is the function of the pleural fluid?
A. To facilitate gas exchange
B. To lubricate the pleural membranes and reduce friction
C. To transport oxygen into the bloodstream
D. To regulate intrapulmonary pressure

Answer 5

B. To lubricate the pleural membranes and reduce friction

Pleural fluid is a serous fluid located between the parietal and visceral pleura that reduces friction during lung expansion and contraction. A buildup of excess pleural fluid (pleural effusion) can impair breathing and oxygen exchange.

Question 6

What makes the respiratory membrane highly efficient for gas exchange?
A. It has thick walls for protection
B. It is made of multiple layers of connective tissue
C. It is extremely thin and has a large surface area
D. It actively pumps oxygen into the blood

Answer 6

C. It is extremely thin and has a large surface area

The respiratory membrane consists of the alveolar and capillary walls, which are thin to allow rapid diffusion of gases. The large surface area of alveoli maximizes oxygen and carbon dioxide exchange. Conditions like pulmonary edema increase membrane thickness and impair gas exchange.

Question 7

Which term describes the movement of air into and out of the lungs?
A. Cellular respiration
B. Pulmonary ventilation
C. External respiration
D. Internal respiration

Answer 7

B. Pulmonary ventilation

Pulmonary ventilation refers to the mechanical process of moving air in and out of the lungs. External respiration is gas exchange between the lungs and blood, internal respiration is gas exchange between blood and tissues, and cellular respiration is ATP production in cells.

Question 8

Which muscle is the primary driver of inspiration?
A. Internal intercostals
B. External obliques
C. Diaphragm
D. Rectus abdominis

Answer 8

C. Diaphragm

The diaphragm is the main muscle responsible for inspiration. When it contracts, the thoracic cavity expands, reducing pressure and allowing air to flow into the lungs. Paralysis of the diaphragm can lead to respiratory failure.

Question 9

What is tidal volume (TV)?
A. The maximum amount of air exhaled after normal expiration
B. The volume of air exchanged during normal breathing
C. The amount of air remaining in the lungs after forced expiration
D. The total volume of exchangeable air

Answer 9

B. The volume of air exchanged during normal breathing

Tidal volume (TV) is the amount of air moved in and out of the lungs during normal, quiet breathing (~500 mL). It is lower in restrictive lung diseases and can increase with exercise.

Question 10

How does oxygen move from the alveoli into the blood?
A. Active transport
B. Osmosis
C. Diffusion
D. Endocytosis

Answer 10

C. Diffusion

Oxygen diffuses from the alveoli (high concentration) into the capillary blood (low concentration). This passive movement is driven by the partial pressure gradient. Impaired diffusion occurs in pulmonary edema or fibrosis.

Question 11

Most oxygen in the blood is transported:
A. Dissolved in plasma
B. Bound to hemoglobin in red blood cells
C. In white blood cells
D. Attached to bicarbonate ions

Answer 11

B. Bound to hemoglobin in red blood cells

98% of oxygen is carried by hemoglobin in red blood cells, while only a small amount dissolves in plasma. Low hemoglobin levels (anemia) reduce oxygen transport capacity.

Question 12

Which brain structure is the primary controller of respiration?
A. Medulla oblongata
B. Cerebellum
C. Hypothalamus
D. Thalamus

Answer 12

A. Medulla oblongata

Rationale: The medulla oblongata contains the respiratory control centers, regulating rate and depth of breathing based on CO₂, O₂, and pH levels.

Question 13

Which term describes abnormally slow and shallow breathing?
A. Apnea
B. Hyperventilation
C. Hypoventilation
D. Dyspnea

Answer 13

C. Hypoventilation

Hypoventilation results in CO₂ buildup (hypercapnia) and acidosis, leading to respiratory failure. Hyperventilation, in contrast, leads to CO₂ loss (hypocapnia) and alkalosis.

Question 14

Which structure helps trap large particles and prevent them from entering the lower respiratory tract?
A. Alveoli
B. Cilia
C. Nasal hairs
D. Bronchi

Answer 14

C. Cillia

Nasal hairs (vibrissae) in the nasal cavity filter out large particles from inhaled air, acting as the first line of defense. Cilia help move mucus and trapped particles upward, but they are found in the trachea and bronchi, not the nasal cavity. The alveoli are responsible for gas exchange and do not filter air.

Question 15

The mucociliary escalator plays an essential role in respiratory defence by:
A. Producing antibodies to fight infections
B. Engulfing and digesting pathogens in the alveoli
C. Trapping debris in mucus and moving it toward the throat
D. Preventing air from reaching the lungs

Answer 15

C. Trapping debris in mucus and moving it toward the throat

The mucociliary escalator consists of cilia and mucus that trap inhaled particles and move them toward the throat for removal. This prevents debris and pathogens from reaching the lungs. Alveolar macrophages, not cilia, engulf pathogens. The system does not produce antibodies or block airflow.

Question 16

What is the function of alveolar macrophages?
A. Producing mucus to trap dust and bacteria
B. Engulfing and destroying pathogens in the lungs
C. Moving trapped particles out of the airway
D. Warming and humidifying inhaled air

Answer 16

B. Engulfing and destroying pathogens in the lungs

Alveolar macrophages are immune cells that phagocytize (engulf and destroy) bacteria, dust, and debris in the alveoli. They are crucial for defense since the alveoli lack mucus and cilia. Mucus production occurs in the upper airways, and cilia, not macrophages, help move particles out of the airway.

Question 17

Which of the following best describes the function of the pleura in the respiratory system?
A. To facilitate the diffusion of gases in the lungs
B. To secrete enzymes that assist with the breakdown of carbon dioxide
C. To create a frictionless environment for the lungs to expand and contract
D. To aid in the oxygenation of blood

Answer 17

C. To create a frictionless environment for the lungs to expand and contract

The pleura is a double-layered membrane surrounding the lungs. The inner layer (visceral pleura) covers the lungs, while the outer layer (parietal pleura) lines the chest cavity. The space between the two layers is filled with pleural fluid, which reduces friction as the lungs expand and contract during respiration, ensuring smooth movement and preventing damage to lung tissue.

Question 18

Which of the following structures is part of the pleural covering of the lungs?
A. Alveolar sacs
B. Visceral pleura
C. Bronchioles
D. Pulmonary arteries

Answer 18

B. Visceral pleura

The visceral pleura is the inner layer of the pleural membrane that directly covers the surface of the lungs. The parietal pleura lines the chest wall. Together, these two layers form the pleural cavity, which is filled with pleural fluid that reduces friction during breathing.

Question 19

A patient is diagnosed with pleuritis. Which of the following is most likely to occur due to inflammation of the pleura?
A. Increased pleural fluid production leading to pleural effusion
B. Decreased lung expansion due to fluid accumulation in the pleural space
C. Pain with deep breathing due to the irritation of the pleura
D. Excessive mucus production in the bronchioles

Answer 19

C. Pain with deep breathing due to the irritation of the pleura

Pleuritis (or pleurisy) occurs when the pleura becomes inflamed, often due to infection or other causes. The inflammation leads to irritation between the visceral and parietal pleura, which can cause sharp, localized pain, particularly during deep breathing or coughing. In severe cases, inflammation may also cause pleural effusion (fluid buildup), but pain is the hallmark symptom.

Question 20

The nurse is assessing a patient with a history of lung surgery. The patient reports chest pain that worsens with deep breaths. Which of the following is the most likely cause of this symptom?
A. Fluid accumulation in the lungs
B. Injury to the diaphragm
C. Irritation of the pleural lining
D. Congestion in the upper respiratory tract

Answer 20

C. Irritation of the pleural lining

Chest pain that worsens with deep breaths is a common symptom of pleuritis or pleural irritation. The pleura are sensitive to pain, and any inflammation or irritation, such as from surgery, can lead to discomfort during respiratory movements. This is typically due to the friction between the parietal and visceral pleura.

Question 21

A patient presents with a pleural effusion. Which of the following would be expected as a result of the fluid accumulation in the pleural space?
A. Decreased lung compliance and difficulty breathing
B. Increased ability of the lungs to expand
C. Decreased ventilation and perfusion matching
D. Reduced blood oxygen levels due to the interference with the diaphragm

Answer 21

A. Decreased lung compliance and difficulty breathing

Pleural effusion occurs when fluid accumulates in the pleural space between the visceral and parietal pleura. This fluid buildup limits lung expansion, decreases lung compliance (the ability of the lungs to stretch), and impairs normal breathing. As a result, patients may experience shortness of breath and difficulty breathing, particularly with deep breaths

Question 22

Which of the following is the primary role of pleural fluid in the pleural cavity?
A. It facilitates the exchange of oxygen and carbon dioxide.
B. It helps maintain the shape of the lungs.
C. It lubricates the pleural surfaces to reduce friction during breathing.
D. It aids in the absorption of carbon dioxide during exhalation.

Answer 22

C. It lubricates the pleural surfaces to reduce friction during breathing.

The pleural fluid, found between the visceral and parietal layers of the pleura, serves primarily as a lubricant. It reduces friction between the lung surfaces and the chest wall during the expansion and contraction of the lungs. This ensures that the lungs can move smoothly during respiration without damaging the pleural membranes.

Question 23

Which of the following best describes the anatomical location of the parietal pleura?
A. It covers the surface of the lungs.
B. It lines the thoracic cavity and the diaphragm.
C. It forms a layer between the bronchi and alveoli.
D. It is located inside the pleural cavity.

Answer 23

B. It lines the thoracic cavity and the diaphragm.

The parietal pleura is the outer layer of the pleura that lines the chest cavity, the diaphragm, and the mediastinum. It does not cover the lungs directly; that function is performed by the visceral pleura. The parietal pleura is also in direct contact with the chest wall and plays a role in the mechanical aspect of breathing.

Question 24

Which of the following is a complication that may arise from a damaged pleura due to trauma or infection?
A. Increased lung elasticity
B. Pneumothorax
C. Excessive oxygenation of the blood
D. Hyper secretion of mucus in the bronchi

Answer 24

B. Pneumothorax

A pneumothorax occurs when air enters the pleural space due to damage to the pleura, causing a collapsed lung. This can be caused by trauma, infection, or medical procedures. The other options (increased lung elasticity, excessive oxygenation, and mucus secretion) are not typically related to damage to the pleura.

Question 25

Which of the following best describes the primary function of the alveolar walls in the respiratory membrane? A. To secrete pulmonary surfactant that helps reduce surface tension B. To allow for efficient gas exchange between the lungs and blood C. To prevent the collapse of the alveoli during expiration D. To facilitate the movement of air into and out of the lungs

Answer 25

B. To allow for efficient gas exchange between the lungs and blood ## Footnote The primary function of the alveolar walls, composed of type I alveolar cells, is to facilitate efficient gas exchange. These cells form a thin barrier that allows oxygen to move from the alveoli into the blood and carbon dioxide to move from the blood into the alveoli. Although surfactant (produced by type II alveolar cells) helps prevent alveolar collapse, its function is secondary to the exchange of gases.

Question 26

Which type of alveolar cell is responsible for producing pulmonary surfactant? A. Type I alveolar cells B. Type II alveolar cells C. Endothelial cells D. Macrophages

Answer 26

B. Type II alveolar cells ## Footnote Type II alveolar cells are responsible for secreting pulmonary surfactant, a substance that reduces surface tension in the alveoli and prevents their collapse during exhalation. Type I alveolar cells, in contrast, are involved in the structural formation of the alveolar walls and gas exchange.

Question 27

The fusion of the basement membranes of the alveolar and capillary cells primarily serves to: A. Facilitate the movement of surfactant into the blood B. Prevent fluid from entering the alveoli C. Create a thin barrier for efficient gas exchange D. Enhance the mechanical support for the lungs

Answer 27

C. Create a thin barrier for efficient gas exchange ## Footnote The fusion of the basement membranes of the alveolar and capillary cells reduces the distance over which gases must diffuse, thereby enhancing the efficiency of gas exchange. This very thin barrier allows for rapid diffusion of oxygen into the blood and carbon dioxide out of the blood into the alveolar space.

Question 28

A nurse is teaching a patient with emphysema about the importance of alveolar structure in gas exchange. The nurse should explain that the alveolar walls are primarily composed of: A. Thick epithelial cells to prevent leakage of gases B. A thin single layer of epithelial cells for efficient gas exchange C. Smooth muscle cells that help regulate airflow D. Collagen fibers to provide structural support for the lungs

Answer 28

B. A thin single layer of epithelial cells for efficient gas exchange ## Footnote The alveolar walls are composed of a single layer of type I epithelial cells, which are thin to allow for efficient diffusion of gases between the alveoli and the capillaries. This structure is essential for the exchange of oxygen and carbon dioxide. Thickening of the alveolar walls, as seen in emphysema, impairs gas exchange.

Question 29

Which of the following structures is directly responsible for carrying oxygen from the alveoli to the body's tissues? A. Alveolar macrophages B. Capillary endothelial cells C. Red blood cells in the capillaries D. Type II alveolar cells

Answer 29

C. Red blood cells in the capillaries ## Footnote Red blood cells in the capillaries are responsible for transporting oxygen from the alveoli to the tissues through the circulatory system. Oxygen binds to hemoglobin in red blood cells, which then circulates through the body to deliver oxygen to tissues.

Question 30

What is the main function of the alveoli in the lungs? A. To produce mucus B. To allow gas exchange between the lungs and blood C. To circulate oxygen to the body D. To filter air entering the lungs

Answer 30

B. To allow gas exchange between the lungs and blood ## Footnote The alveoli are the tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged between the lungs and blood.

Question 31

How does the respiratory membrane help with the diffusion of gases? A. By thickening the barrier between the alveoli and capillaries B. By reducing the space between the alveoli and capillaries C. By increasing the amount of fluid in the alveoli D. By providing more surface area for breathing

Answer 31

B. By reducing the space between the alveoli and capillaries ## Footnote The respiratory membrane is very thin, which allows oxygen and carbon dioxide to diffuse easily between the alveoli and the blood in the capillaries.

Question 32

Which of the following is true about the alveolar walls? A. They are made up of thick layers to protect the lungs B. They are thin to allow for gas exchange C. They contain smooth muscle to regulate airflow D. They produce mucus to trap particles

Answer 32

B. They are thin to allow for gas exchange ## Footnote The alveolar walls are thin to allow oxygen and carbon dioxide to diffuse quickly between the alveoli and the blood.

Question 33

Which of the following best defines cellular respiration? A. The process of exchanging gases between the lungs and blood B. The breakdown of glucose in cells to produce energy C. The movement of air into and out of the lungs D. The release of carbon dioxide into the atmosphere

Answer 33

B. The breakdown of glucose in cells to produce energy ## Footnote Cellular respiration is the process by which cells use oxygen to break down glucose to produce energy (ATP) and release carbon dioxide as a byproduct.

Question 34

What is external respiration? A. The movement of air into and out of the lungs B. The exchange of gases between the lungs and the blood C. The use of oxygen in cells to produce energy D. The exchange of gases between the blood and body tissues

Answer 34

B. The exchange of gases between the lungs and the blood ## Footnote External respiration refers to the exchange of gases (oxygen and carbon dioxide) between the lungs and the blood in the capillaries.

Question 35

Which of the following best defines internal respiration? A. The exchange of gases between the lungs and blood B. The movement of air into and out of the lungs C. The exchange of gases between the blood and tissues of the body D. The breakdown of glucose to produce energy in the body

Answer 35

C. The exchange of gases between the blood and tissues of the body ## Footnote Internal respiration refers to the exchange of oxygen from the blood to the tissues and carbon dioxide from the tissues to the blood.

Question 36

What does pulmonary ventilation refer to? A. The breakdown of glucose in cells to produce energy B. The process of gas exchange between the lungs and blood C. The movement of air into and out of the lungs D. The exchange of gases between the blood and tissues

Answer 36

Answer: C. The movement of air into and out of the lungs ## Footnote Pulmonary ventilation refers to the process of moving air into and out of the lungs, also known as breathing (inhalation and exhalation).

Question 37

Which of the following defines expiration? A. The process of taking air into the lungs B. The process of releasing carbon dioxide from the blood C. The process of breathing out air from the lungs D. The process of oxygen entering the blood

Answer 37

C. The process of breathing out air from the lungs ## Footnote Expiration is the process of breathing out air from the lungs, expelling carbon dioxide from the body.

Question 38

What is inspiration? A. The movement of air out of the lungs B. The exchange of gases between the lungs and blood C. The process of breathing in air into the lungs D. The breakdown of glucose in cells for energy

Answer 38

C. The process of breathing in air into the lungs ## Footnote Inspiration refers to the process of taking air into the lungs, bringing in oxygen to be exchanged for carbon dioxide.

Question 39

What is tidal volume? A. The amount of air inhaled or exhaled during normal breathing B. The maximum amount of air that can be exhaled after a normal expiration C. The amount of air remaining in the lungs after maximal exhalation D. The maximum amount of air that can be inhaled after a normal inhalation

Answer 39

A. The amount of air inhaled or exhaled during normal breathing ## Footnote Tidal volume refers to the volume of air that is inhaled or exhaled with each normal breath, typically around 500 mL in an adult at rest.

Question 40

What does vital capacity refer to? A. The total amount of air in the lungs after inhalation B. The total amount of air that can be exhaled after maximal inhalation C. The amount of air remaining in the lungs after a normal exhalation D. The volume of air moved in and out during normal breathing

Answer 40

B. The total amount of air that can be exhaled after maximal inhalation ## Footnote Vital capacity is the total amount of air that can be exhaled after taking a deep breath in. It includes the tidal volume, inspiratory reserve volume, and expiratory reserve volume.

Question 41

Which of the following defines expiratory reserve volume? A. The amount of air that remains in the lungs after maximal exhalation B. The amount of air that can be inhaled after a normal breath C. The volume of air exhaled after a normal breath D. The maximum amount of air that can be exhaled after a normal exhalation

Answer 41

D. The maximum amount of air that can be exhaled after a normal exhalation ## Footnote Expiratory reserve volume refers to the maximum amount of air that can be forcefully exhaled after a normal tidal exhalation.

Question 42

What is inspiratory reserve volume? A. The amount of air that remains in the lungs after normal exhalation B. The volume of air inhaled during normal breathing C. The maximum amount of air that can be inhaled after a normal inhalation D. The amount of air that can be exhaled after a deep inhalation

Answer 42

C. The maximum amount of air that can be inhaled after a normal inhalation ## Footnote Inspiratory reserve volume is the amount of air that can be forcefully inhaled after a normal tidal inhalation.

Question 43

Which of the following describes residual air? A. The volume of air remaining in the lungs after maximal exhalation B. The amount of air that is exhaled during normal breathing C. The maximum volume of air that can be inhaled after normal inspiration D. The volume of air inhaled during a deep breath

Answer 43

A. The volume of air remaining in the lungs after maximal exhalation ## Footnote Residual air (or residual volume) is the amount of air that remains in the lungs after a maximal exhalation, preventing the lungs from collapsing.

Question 44

Which of the following best describes the process of gas exchange in the lungs? A. Oxygen moves from the blood into the alveoli, and carbon dioxide moves from the alveoli into the blood. B. Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli. C. Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the cells into the alveoli. D. Oxygen moves from the blood into the alveoli, and carbon dioxide moves from the cells into the blood.

Answer 44

B. Oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli. ## Footnote In the lungs (external respiration), oxygen from the alveoli moves into the blood, and carbon dioxide from the blood moves into the alveoli to be exhaled.

Question 45

Which of the following best describes the process of gas exchange in the tissues? A. Oxygen moves from the blood into the alveoli, and carbon dioxide moves from the alveoli into the blood. B. Oxygen moves from the blood into the cells, and carbon dioxide moves from the cells into the blood. C. Oxygen moves from the cells into the blood, and carbon dioxide moves from the blood into the cells. D. Oxygen moves from the blood into the alveoli, and carbon dioxide moves from the blood into the cells.

Answer 45

B. Oxygen moves from the blood into the cells, and carbon dioxide moves from the cells into the blood. ## Footnote In the tissues (internal respiration), oxygen moves from the blood into the cells, and carbon dioxide, produced by metabolism in the cells, moves from the cells into the blood.

Question 46

Which of the following best defines apnea? A. Rapid or shallow breathing that leads to excessive loss of carbon dioxide B. A temporary cessation of breathing, typically lasting a few seconds to a minute C. Slow and shallow breathing that results in inadequate oxygen intake D. Difficulty in breathing during physical activity

Answer 46

B. A temporary cessation of breathing, typically lasting a few seconds to a minute ## Footnote Apnea refers to the temporary cessation of breathing, which can occur during sleep (sleep apnea) or as a result of various medical conditions.

Question 47

What is the definition of hyperventilation? A. Breathing that is slow and shallow, leading to a buildup of carbon dioxide B. Rapid or deep breathing that exceeds the body's demand for oxygen C. A temporary pause in breathing lasting for several seconds D. Breathing that occurs at a normal rate and depth

Answer 47

B. Rapid or deep breathing that exceeds the body's demand for oxygen ## Footnote Hyperventilation is characterised by rapid or deep breathing, which causes excessive loss of carbon dioxide from the blood and leads to respiratory alkalosis.

Question 48

Which of the following best describes hypoventilation? A. Breathing that is slow or shallow, leading to inadequate oxygen intake and a buildup of carbon dioxide B. Rapid and deep breathing that leads to excessive loss of carbon dioxide C. A condition where breathing completely ceases for a few moments D. Normal breathing during periods of rest and relaxation

Answer 48

A. Breathing that is slow or shallow, leading to inadequate oxygen intake and a buildup of carbon dioxide ## Footnote Hypoventilation is characterised by slow or shallow breathing, which results in insufficient oxygen intake and an accumulation of carbon dioxide in the blood.