Galen College NU 110 Exam 2 (pdf) | 2026/2027 | Integrated Human
Sciences Q&A | Human Sciences
1. Which of the following lists the four phases of respiration in correct
sequential order?
A) External gas exchange, gas transport in blood, pulmonary ventilation,
internal gas exchange
B) Pulmonary ventilation, external gas exchange, gas transport in blood,
internal gas exchange
C) Gas transport in blood, internal gas exchange, pulmonary ventilation,
external gas exchange
D) Internal gas exchange, gas transport in blood, external gas exchange,
pulmonary ventilation
Correct Answer: Pulmonary ventilation, external gas exchange, gas transport
in blood, internal gas exchange
Rationale: The four phases of respiration occur sequentially: pulmonary
ventilation (air movement in/out of lungs), external gas exchange (gas
exchange at alveoli), gas transport in the blood (circulation of gases), and
internal gas exchange (exchange at the tissues). Any other order would
disrupt the physiological pathway of oxygen from the environment to the
cells.
2. What is the primary function of the nasal cavity within the respiratory
system?
A) To produce sound for speech
B) To filter, warm, and moisten incoming air
C) To exchange gases with the blood
D) To transport air to the larynx
Correct Answer: To filter, warm, and moisten incoming air
,Rationale: The nasal cavity is lined with mucous membranes and rich blood
supply that filter, warm, and moisten inhaled air before it reaches the lower
airways. Gas exchange occurs in the alveoli, sound production in the larynx,
and air transport is a function of the entire airway.
3. Which structure connects the pharynx to the trachea and houses the vocal
cords?
A) Bronchi
B) Larynx
C) Alveoli
D) Epiglottis
Correct Answer: Larynx
Rationale: The larynx connects the pharynx with the trachea and contains
the vocal cords for sound production. The bronchi branch from the trachea,
alveoli are the sites of gas exchange, and the epiglottis covers the larynx
during swallowing.
4. During the process of external gas exchange, which movement of gases
occurs across the alveolar-capillary membrane?
A) Oxygen diffuses from the blood into the alveoli; carbon dioxide diffuses
from the alveoli into the blood
B) Oxygen and carbon dioxide both diffuse from the alveoli into the blood
C) Oxygen diffuses from the alveoli into the blood; carbon dioxide diffuses
from the blood into the alveoli
D) Oxygen and carbon dioxide both diffuse from the blood into the alveoli
,Correct Answer: Oxygen diffuses from the alveoli into the blood; carbon
dioxide diffuses from the blood into the alveoli
Rationale: External gas exchange occurs in the lungs as oxygen diffuses from
the alveoli (high concentration) into the pulmonary capillary blood, while
carbon dioxide diffuses from the blood (high concentration) into the alveoli to
be exhaled. This follows the principles of diffusion down concentration
gradients.
5. What is the role of surfactant in the alveoli?
A) To trap and remove pathogens from the airway
B) To maintain surface tension and prevent alveolar collapse
C) To transport oxygen to the blood
D) To produce mucus for the respiratory tract
Correct Answer: To maintain surface tension and prevent alveolar collapse
Rationale: Surfactant is a chemical produced in the lungs that reduces
surface tension within the alveoli, keeping them open and preventing
collapse during exhalation. Without surfactant, the alveoli would stick
together, making breathing extremely difficult.
6. Which gas is the primary regulator of respiration?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Correct Answer: Carbon dioxide
, Rationale: Carbon dioxide (CO₂) is the primary regulator of respiration. The
respiratory center in the brainstem senses increased CO₂ (and resulting H⁺)
and increases the rate and depth of breathing to eliminate excess CO₂.
Oxygen plays a lesser role in respiratory drive.
7. Hydrogen ions (H⁺) stimulate which receptors to regulate the rate and
depth of breathing?
A) Peripheral chemoreceptors in the carotid bodies
B) Central chemoreceptors in the brainstem
C) Stretch receptors in the lungs
D) Irritant receptors in the airway
Correct Answer: Central chemoreceptors in the brainstem
Rationale: Hydrogen ions (H⁺) stimulate central chemoreceptors located in
the brainstem to either increase or decrease the rate and depth of breathing.
These chemoreceptors are sensitive to changes in cerebrospinal fluid pH,
which reflects CO₂ levels.
8. What is the term for the movement of air into and out of the lungs?
A) Diffusion
B) Perfusion
C) Ventilation
D) Compliance
Correct Answer: Ventilation
Sciences Q&A | Human Sciences
1. Which of the following lists the four phases of respiration in correct
sequential order?
A) External gas exchange, gas transport in blood, pulmonary ventilation,
internal gas exchange
B) Pulmonary ventilation, external gas exchange, gas transport in blood,
internal gas exchange
C) Gas transport in blood, internal gas exchange, pulmonary ventilation,
external gas exchange
D) Internal gas exchange, gas transport in blood, external gas exchange,
pulmonary ventilation
Correct Answer: Pulmonary ventilation, external gas exchange, gas transport
in blood, internal gas exchange
Rationale: The four phases of respiration occur sequentially: pulmonary
ventilation (air movement in/out of lungs), external gas exchange (gas
exchange at alveoli), gas transport in the blood (circulation of gases), and
internal gas exchange (exchange at the tissues). Any other order would
disrupt the physiological pathway of oxygen from the environment to the
cells.
2. What is the primary function of the nasal cavity within the respiratory
system?
A) To produce sound for speech
B) To filter, warm, and moisten incoming air
C) To exchange gases with the blood
D) To transport air to the larynx
Correct Answer: To filter, warm, and moisten incoming air
,Rationale: The nasal cavity is lined with mucous membranes and rich blood
supply that filter, warm, and moisten inhaled air before it reaches the lower
airways. Gas exchange occurs in the alveoli, sound production in the larynx,
and air transport is a function of the entire airway.
3. Which structure connects the pharynx to the trachea and houses the vocal
cords?
A) Bronchi
B) Larynx
C) Alveoli
D) Epiglottis
Correct Answer: Larynx
Rationale: The larynx connects the pharynx with the trachea and contains
the vocal cords for sound production. The bronchi branch from the trachea,
alveoli are the sites of gas exchange, and the epiglottis covers the larynx
during swallowing.
4. During the process of external gas exchange, which movement of gases
occurs across the alveolar-capillary membrane?
A) Oxygen diffuses from the blood into the alveoli; carbon dioxide diffuses
from the alveoli into the blood
B) Oxygen and carbon dioxide both diffuse from the alveoli into the blood
C) Oxygen diffuses from the alveoli into the blood; carbon dioxide diffuses
from the blood into the alveoli
D) Oxygen and carbon dioxide both diffuse from the blood into the alveoli
,Correct Answer: Oxygen diffuses from the alveoli into the blood; carbon
dioxide diffuses from the blood into the alveoli
Rationale: External gas exchange occurs in the lungs as oxygen diffuses from
the alveoli (high concentration) into the pulmonary capillary blood, while
carbon dioxide diffuses from the blood (high concentration) into the alveoli to
be exhaled. This follows the principles of diffusion down concentration
gradients.
5. What is the role of surfactant in the alveoli?
A) To trap and remove pathogens from the airway
B) To maintain surface tension and prevent alveolar collapse
C) To transport oxygen to the blood
D) To produce mucus for the respiratory tract
Correct Answer: To maintain surface tension and prevent alveolar collapse
Rationale: Surfactant is a chemical produced in the lungs that reduces
surface tension within the alveoli, keeping them open and preventing
collapse during exhalation. Without surfactant, the alveoli would stick
together, making breathing extremely difficult.
6. Which gas is the primary regulator of respiration?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Correct Answer: Carbon dioxide
, Rationale: Carbon dioxide (CO₂) is the primary regulator of respiration. The
respiratory center in the brainstem senses increased CO₂ (and resulting H⁺)
and increases the rate and depth of breathing to eliminate excess CO₂.
Oxygen plays a lesser role in respiratory drive.
7. Hydrogen ions (H⁺) stimulate which receptors to regulate the rate and
depth of breathing?
A) Peripheral chemoreceptors in the carotid bodies
B) Central chemoreceptors in the brainstem
C) Stretch receptors in the lungs
D) Irritant receptors in the airway
Correct Answer: Central chemoreceptors in the brainstem
Rationale: Hydrogen ions (H⁺) stimulate central chemoreceptors located in
the brainstem to either increase or decrease the rate and depth of breathing.
These chemoreceptors are sensitive to changes in cerebrospinal fluid pH,
which reflects CO₂ levels.
8. What is the term for the movement of air into and out of the lungs?
A) Diffusion
B) Perfusion
C) Ventilation
D) Compliance
Correct Answer: Ventilation
