,BIOD151/BIOD 151 Module 2 Exam | Essential Human
Anatomy & Physiology I with Lab | Portage Learning | Q & A |
2026/2027 Edition (PDF)
1. Which of the following best describes the primary function of the cilia found in the respiratory
epithelium?
A) To produce mucus for trapping pathogens
B) To sweep debris-laden mucus toward the pharynx for removal
C) To warm incoming air before it reaches the lungs
D) To facilitate gas exchange between the alveoli and capillaries
Correct Answer: To sweep debris-laden mucus toward the pharynx for removal
Rationale: The cilia of the respiratory epithelium are small, hair-like structures that beat in a coordinated
manner to move mucus, along with trapped debris and pathogens, upward toward the pharynx. This
"mucociliary escalator" is a crucial defense mechanism. Mucus production is performed by goblet cells,
while warming air is a function of the nasal passages.
2. What type of epithelium lines the majority of the respiratory tract from the nasal cavity to the
bronchi?
A) Simple squamous epithelium
B) Stratified squamous epithelium
C) Pseudostratified ciliated columnar epithelium
D) Transitional epithelium
Correct Answer: Pseudostratified ciliated columnar epithelium
Rationale: The respiratory tract is primarily lined with pseudostratified ciliated columnar epithelium. It
appears stratified because the nuclei are at different heights, but all cells contact the basement
membrane. This epithelium is specialized for protection and mucus clearance, unlike simple squamous
epithelium which is found in alveoli for gas exchange.
,3. In which of the following areas of the respiratory tract would cartilage NOT be found?
A) Trachea
B) Bronchi
C) Larynx
D) Alveoli
Correct Answer: Alveoli
Rationale: Cartilage rings provide structural support to the trachea, bronchi, and larynx, keeping these
airways open. The alveoli are the tiny air sacs where gas exchange occurs and are composed of a thin
layer of epithelial cells; they lack cartilage, allowing for efficient diffusion.
4. A premature infant is having difficulty breathing due to a lack of pulmonary surfactant. Which type of
alveolar cell is primarily responsible for producing this substance?
A) Type I alveolar cells
B) Type II alveolar cells
C) Alveolar macrophages
D) Goblet cells
Correct Answer: Type II alveolar cells
Rationale: Type II alveolar cells are responsible for producing and secreting pulmonary surfactant.
Surfactant reduces surface tension within the alveoli, preventing them from collapsing during
exhalation. A deficiency of surfactant, as seen in premature infants, leads to respiratory distress
syndrome.
5. Which of the following correctly describes the relationship between gas volume and pressure, as
stated by Boyle's law?
A) Gas volume is directly proportional to pressure
B) Gas volume is inversely proportional to pressure
C) Gas volume is independent of pressure
, D) Gas volume is directly proportional to the square of the pressure
Correct Answer: Gas volume is inversely proportional to pressure
Rationale: Boyle's law states that the pressure of a gas is inversely proportional to its volume. This
principle is fundamental to the mechanics of breathing, as an increase in thoracic volume during
inhalation leads to a decrease in intra-alveolar pressure, causing air to flow into the lungs.
6. Which of the following statements regarding the mechanics of breathing is TRUE?
A) Positive pressure is used to move air into the lungs
B) During exhalation, the diaphragm contracts to actively push air out
C) Negative pressure draws air into the lungs during inhalation
D) The rib cage is lowered during inhalation to pull the lungs open
Correct Answer: Negative pressure draws air into the lungs during inhalation
Rationale: Inhalation is an active process driven by negative pressure. The diaphragm contracts and
moves downward, and the rib cage lifts, expanding the thoracic cavity. This increases lung volume,
decreasing intrapulmonary pressure below atmospheric pressure, which draws air in.
7. What is the primary function of the goblet cells found in the respiratory epithelium?
A) To sweep mucus toward the pharynx
B) To produce mucus
C) To facilitate gas exchange
D) To trap and destroy pathogens
Correct Answer: To produce mucus
Rationale: Goblet cells are specialized epithelial cells that produce and secrete mucus. This mucus traps
inhaled particles, pathogens, and debris, preventing them from reaching the delicate alveoli. The cilia
then sweep the mucus upward for expulsion or swallowing.
Anatomy & Physiology I with Lab | Portage Learning | Q & A |
2026/2027 Edition (PDF)
1. Which of the following best describes the primary function of the cilia found in the respiratory
epithelium?
A) To produce mucus for trapping pathogens
B) To sweep debris-laden mucus toward the pharynx for removal
C) To warm incoming air before it reaches the lungs
D) To facilitate gas exchange between the alveoli and capillaries
Correct Answer: To sweep debris-laden mucus toward the pharynx for removal
Rationale: The cilia of the respiratory epithelium are small, hair-like structures that beat in a coordinated
manner to move mucus, along with trapped debris and pathogens, upward toward the pharynx. This
"mucociliary escalator" is a crucial defense mechanism. Mucus production is performed by goblet cells,
while warming air is a function of the nasal passages.
2. What type of epithelium lines the majority of the respiratory tract from the nasal cavity to the
bronchi?
A) Simple squamous epithelium
B) Stratified squamous epithelium
C) Pseudostratified ciliated columnar epithelium
D) Transitional epithelium
Correct Answer: Pseudostratified ciliated columnar epithelium
Rationale: The respiratory tract is primarily lined with pseudostratified ciliated columnar epithelium. It
appears stratified because the nuclei are at different heights, but all cells contact the basement
membrane. This epithelium is specialized for protection and mucus clearance, unlike simple squamous
epithelium which is found in alveoli for gas exchange.
,3. In which of the following areas of the respiratory tract would cartilage NOT be found?
A) Trachea
B) Bronchi
C) Larynx
D) Alveoli
Correct Answer: Alveoli
Rationale: Cartilage rings provide structural support to the trachea, bronchi, and larynx, keeping these
airways open. The alveoli are the tiny air sacs where gas exchange occurs and are composed of a thin
layer of epithelial cells; they lack cartilage, allowing for efficient diffusion.
4. A premature infant is having difficulty breathing due to a lack of pulmonary surfactant. Which type of
alveolar cell is primarily responsible for producing this substance?
A) Type I alveolar cells
B) Type II alveolar cells
C) Alveolar macrophages
D) Goblet cells
Correct Answer: Type II alveolar cells
Rationale: Type II alveolar cells are responsible for producing and secreting pulmonary surfactant.
Surfactant reduces surface tension within the alveoli, preventing them from collapsing during
exhalation. A deficiency of surfactant, as seen in premature infants, leads to respiratory distress
syndrome.
5. Which of the following correctly describes the relationship between gas volume and pressure, as
stated by Boyle's law?
A) Gas volume is directly proportional to pressure
B) Gas volume is inversely proportional to pressure
C) Gas volume is independent of pressure
, D) Gas volume is directly proportional to the square of the pressure
Correct Answer: Gas volume is inversely proportional to pressure
Rationale: Boyle's law states that the pressure of a gas is inversely proportional to its volume. This
principle is fundamental to the mechanics of breathing, as an increase in thoracic volume during
inhalation leads to a decrease in intra-alveolar pressure, causing air to flow into the lungs.
6. Which of the following statements regarding the mechanics of breathing is TRUE?
A) Positive pressure is used to move air into the lungs
B) During exhalation, the diaphragm contracts to actively push air out
C) Negative pressure draws air into the lungs during inhalation
D) The rib cage is lowered during inhalation to pull the lungs open
Correct Answer: Negative pressure draws air into the lungs during inhalation
Rationale: Inhalation is an active process driven by negative pressure. The diaphragm contracts and
moves downward, and the rib cage lifts, expanding the thoracic cavity. This increases lung volume,
decreasing intrapulmonary pressure below atmospheric pressure, which draws air in.
7. What is the primary function of the goblet cells found in the respiratory epithelium?
A) To sweep mucus toward the pharynx
B) To produce mucus
C) To facilitate gas exchange
D) To trap and destroy pathogens
Correct Answer: To produce mucus
Rationale: Goblet cells are specialized epithelial cells that produce and secrete mucus. This mucus traps
inhaled particles, pathogens, and debris, preventing them from reaching the delicate alveoli. The cilia
then sweep the mucus upward for expulsion or swallowing.
