BIOL 252 Human Anatomy & Physiology II w/Lab | Module 5 Exam
Review WITH CORRECT ANSWERS WELL ELABORATED AN IN-DEPTHN
RATIONALE LATEST EDITION 2026!
Respiratory System & Acid-Base Balance
Question 1
What happens when carbon dioxide accumulates in the body?
A) Oxygen levels increase.
B) Cellular respiration stops.
C) pH rises, causing alkalosis.
D) pH drops, causing acidosis.
Correct ANSWER: D) pH drops, causing acidosis.
Rationale: When CO₂ accumulates in the body, it reacts with water to form carbonic acid (H₂CO₃), which
dissociates into H⁺ and HCO₃⁻ ions. The increased H⁺ concentration lowers blood pH, leading to
respiratory acidosis. This is a classic acid-base disturbance seen in hypoventilation conditions.
Question 2
What is the function of the mucosal lining in the nasal cavity?
A) Absorbs nutrients
,B) Secretes enzymes for digestion
C) Stimulates olfactory receptors directly
D) Traps particles and contains antimicrobial proteins
Correct ANSWER: D) Traps particles and contains antimicrobial proteins.
Rationale: The nasal mucosa contains goblet cells that produce mucus to trap dust, pathogens, and
particulate matter. It also contains lysozyme and other antimicrobial proteins that help destroy inhaled
bacteria. The mucus is moved toward the pharynx by ciliary action for elimination.
Question 3
Identify the structures labelled by the following letters:
J → Nasal meatuses
H → Trachea
E → Palatine tonsil
N → Soft palate
Correct ANSWER: All identifications are correct.
Rationale:
Nasal meatuses (J): Grooves beneath the nasal conchae that channel airflow and increase surface area
for warming/humidifying air.
,Trachea (H): The windpipe that extends from the larynx to the primary bronchi, reinforced by C-shaped
cartilage rings.
Palatine tonsil (E): Paired lymphoid tissue located at the posterior oral cavity; part of the tonsillar ring
(Waldeyer's ring).
Soft palate (N): Posterior muscular portion of the palate that elevates during swallowing to close off the
nasopharynx.
Question 4
Which of the following correctly describes the pathway of air during inspiration?
A) Nose → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
B) Nose → larynx → pharynx → trachea → bronchioles → bronchi → alveoli
C) Nose → trachea → pharynx → larynx → bronchi → bronchioles → alveoli
D) Nose → pharynx → trachea → larynx → bronchioles → bronchi → alveoli
Correct ANSWER: A) Nose → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
Rationale: The correct anatomical pathway for inspired air is: nasal cavity → pharynx (nasopharynx,
oropharynx, laryngopharynx) → larynx → trachea → primary bronchi → secondary bronchi → tertiary
bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar
sacs → alveoli. Option A provides the correct sequence.
Question 5
Which type of alveolar cell is responsible for producing surfactant?
A) Type I alveolar cells
, B) Type II alveolar cells
C) Alveolar macrophages
D) Goblet cells
Correct ANSWER: B) Type II alveolar cells
Rationale: Type II pneumocytes (alveolar cells) are cuboidal epithelial cells that secrete pulmonary
surfactant, a phospholipoprotein that reduces surface tension within the alveoli. This prevents alveolar
collapse (atelectasis) during expiration. Type I cells are squamous and primarily involved in gas
exchange, while alveolar macrophages are phagocytic cells for defense.
Question 6
What is the primary muscle of inspiration?
A) External intercostals
B) Internal intercostals
C) Diaphragm
D) Abdominal muscles
Correct ANSWER: C) Diaphragm
Rationale: The diaphragm is the primary inspiratory muscle. When it contracts, it flattens and moves
downward, increasing the thoracic cavity's vertical dimension. This creates negative intrapleural
pressure, drawing air into the lungs. External intercostals assist during forced inspiration, while internal
intercostals and abdominal muscles are primarily expiratory muscles.
Review WITH CORRECT ANSWERS WELL ELABORATED AN IN-DEPTHN
RATIONALE LATEST EDITION 2026!
Respiratory System & Acid-Base Balance
Question 1
What happens when carbon dioxide accumulates in the body?
A) Oxygen levels increase.
B) Cellular respiration stops.
C) pH rises, causing alkalosis.
D) pH drops, causing acidosis.
Correct ANSWER: D) pH drops, causing acidosis.
Rationale: When CO₂ accumulates in the body, it reacts with water to form carbonic acid (H₂CO₃), which
dissociates into H⁺ and HCO₃⁻ ions. The increased H⁺ concentration lowers blood pH, leading to
respiratory acidosis. This is a classic acid-base disturbance seen in hypoventilation conditions.
Question 2
What is the function of the mucosal lining in the nasal cavity?
A) Absorbs nutrients
,B) Secretes enzymes for digestion
C) Stimulates olfactory receptors directly
D) Traps particles and contains antimicrobial proteins
Correct ANSWER: D) Traps particles and contains antimicrobial proteins.
Rationale: The nasal mucosa contains goblet cells that produce mucus to trap dust, pathogens, and
particulate matter. It also contains lysozyme and other antimicrobial proteins that help destroy inhaled
bacteria. The mucus is moved toward the pharynx by ciliary action for elimination.
Question 3
Identify the structures labelled by the following letters:
J → Nasal meatuses
H → Trachea
E → Palatine tonsil
N → Soft palate
Correct ANSWER: All identifications are correct.
Rationale:
Nasal meatuses (J): Grooves beneath the nasal conchae that channel airflow and increase surface area
for warming/humidifying air.
,Trachea (H): The windpipe that extends from the larynx to the primary bronchi, reinforced by C-shaped
cartilage rings.
Palatine tonsil (E): Paired lymphoid tissue located at the posterior oral cavity; part of the tonsillar ring
(Waldeyer's ring).
Soft palate (N): Posterior muscular portion of the palate that elevates during swallowing to close off the
nasopharynx.
Question 4
Which of the following correctly describes the pathway of air during inspiration?
A) Nose → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
B) Nose → larynx → pharynx → trachea → bronchioles → bronchi → alveoli
C) Nose → trachea → pharynx → larynx → bronchi → bronchioles → alveoli
D) Nose → pharynx → trachea → larynx → bronchioles → bronchi → alveoli
Correct ANSWER: A) Nose → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
Rationale: The correct anatomical pathway for inspired air is: nasal cavity → pharynx (nasopharynx,
oropharynx, laryngopharynx) → larynx → trachea → primary bronchi → secondary bronchi → tertiary
bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar
sacs → alveoli. Option A provides the correct sequence.
Question 5
Which type of alveolar cell is responsible for producing surfactant?
A) Type I alveolar cells
, B) Type II alveolar cells
C) Alveolar macrophages
D) Goblet cells
Correct ANSWER: B) Type II alveolar cells
Rationale: Type II pneumocytes (alveolar cells) are cuboidal epithelial cells that secrete pulmonary
surfactant, a phospholipoprotein that reduces surface tension within the alveoli. This prevents alveolar
collapse (atelectasis) during expiration. Type I cells are squamous and primarily involved in gas
exchange, while alveolar macrophages are phagocytic cells for defense.
Question 6
What is the primary muscle of inspiration?
A) External intercostals
B) Internal intercostals
C) Diaphragm
D) Abdominal muscles
Correct ANSWER: C) Diaphragm
Rationale: The diaphragm is the primary inspiratory muscle. When it contracts, it flattens and moves
downward, increasing the thoracic cavity's vertical dimension. This creates negative intrapleural
pressure, drawing air into the lungs. External intercostals assist during forced inspiration, while internal
intercostals and abdominal muscles are primarily expiratory muscles.
