1|Page
Exam 4: NUR242/ NUR 242 (Latest 2025)
Medical-Surgical Nursing Exam | Questions and
Verified Answers| 100% Correct| Grade A-
Galen
What is ventilation? - .....ANSWER ...✔✔ the
movement of air into and out of the lungs
What is perfusion? - .....ANSWER ...✔✔ the circulation
of blood through the lungs
What are central chemoreceptors responsive to? -
.....ANSWER ...✔✔ increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? -
.....ANSWER ...✔✔ decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
,2|Page
What are elastic forces? - .....ANSWER ...✔✔ lungs
recoil due to elastin, collagen, fibrin
What are surface forces? - .....ANSWER ...✔✔
surface tension due to water-air interface
What is airway resistance? - .....ANSWER ...✔✔
opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? - .....ANSWER
...✔✔ ease with which the lungs can be inflated
What is lung distensibility increased in? - .....ANSWER
...✔✔ neonates and children;
emphysema
What is lung distensibility decreased in? - .....ANSWER
...✔✔ elderly;
pneumonia, pulmonary edema, ARDS, atelectasis,
fibrosis
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What is surfactant? - .....ANSWER ...✔✔ complex
substance lining the alveoli and smallest bronchioles
containing phospholipids and a number of apoproteins
which reduces surface tension throughout the lungs,
thereby contributing to its general compliance;
stabilizes the alveoli and keeps them dry
What produces surfactant? - .....ANSWER ...✔✔
produced by the Type II alveolar cells
What is Ohm's law? - .....ANSWER ...✔✔ velocity =
driving force/resistance
What is Poiseuille law? - .....ANSWER ...✔✔
resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? -
.....ANSWER ...✔✔ the resistance goes up
How is the ventilation distributed in the lungs? -
.....ANSWER ...✔✔ the top of the lungs are more
distended and less compliant whereas the lower lung is
small and highly compliant
, 4|Page
What factors affect lung perfusion? - .....ANSWER
...✔✔ lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? - .....ANSWER ...✔✔
vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? - .....ANSWER
...✔✔ pulmonary hypertension
What factors affect alveolar-capillary diffusion? -
.....ANSWER ...✔✔ capillary permeability;
surface area available for diffusion;
concentration gradient for the gas;
distance for diffusion
What causes right shifts (decreased affinity) in
Hemoglobin-O2 affinity? - .....ANSWER ...✔✔
acidemia;
hyperthermia;
hypercarbia
Exam 4: NUR242/ NUR 242 (Latest 2025)
Medical-Surgical Nursing Exam | Questions and
Verified Answers| 100% Correct| Grade A-
Galen
What is ventilation? - .....ANSWER ...✔✔ the
movement of air into and out of the lungs
What is perfusion? - .....ANSWER ...✔✔ the circulation
of blood through the lungs
What are central chemoreceptors responsive to? -
.....ANSWER ...✔✔ increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? -
.....ANSWER ...✔✔ decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
,2|Page
What are elastic forces? - .....ANSWER ...✔✔ lungs
recoil due to elastin, collagen, fibrin
What are surface forces? - .....ANSWER ...✔✔
surface tension due to water-air interface
What is airway resistance? - .....ANSWER ...✔✔
opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? - .....ANSWER
...✔✔ ease with which the lungs can be inflated
What is lung distensibility increased in? - .....ANSWER
...✔✔ neonates and children;
emphysema
What is lung distensibility decreased in? - .....ANSWER
...✔✔ elderly;
pneumonia, pulmonary edema, ARDS, atelectasis,
fibrosis
,3|Page
What is surfactant? - .....ANSWER ...✔✔ complex
substance lining the alveoli and smallest bronchioles
containing phospholipids and a number of apoproteins
which reduces surface tension throughout the lungs,
thereby contributing to its general compliance;
stabilizes the alveoli and keeps them dry
What produces surfactant? - .....ANSWER ...✔✔
produced by the Type II alveolar cells
What is Ohm's law? - .....ANSWER ...✔✔ velocity =
driving force/resistance
What is Poiseuille law? - .....ANSWER ...✔✔
resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? -
.....ANSWER ...✔✔ the resistance goes up
How is the ventilation distributed in the lungs? -
.....ANSWER ...✔✔ the top of the lungs are more
distended and less compliant whereas the lower lung is
small and highly compliant
, 4|Page
What factors affect lung perfusion? - .....ANSWER
...✔✔ lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? - .....ANSWER ...✔✔
vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? - .....ANSWER
...✔✔ pulmonary hypertension
What factors affect alveolar-capillary diffusion? -
.....ANSWER ...✔✔ capillary permeability;
surface area available for diffusion;
concentration gradient for the gas;
distance for diffusion
What causes right shifts (decreased affinity) in
Hemoglobin-O2 affinity? - .....ANSWER ...✔✔
acidemia;
hyperthermia;
hypercarbia
