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NUR 242 MED SURG EXAM 3| CERTIFIED
QUESTIONS WITH ANSWERS 2026
What is ventilation? - correct-answer -the movement of air into and out of the lungs
What is perfusion? - correct-answer -the circulation of blood through the lungs
What are central chemoreceptors responsive to? - correct-answer -increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? - correct-answer -decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces? - correct-answer -lungs recoil due to elastin, collagen, fibrin
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What are surface forces? - correct-answer -surface tension due to water-air interface
What is airway resistance? - correct-answer -opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? - correct-answer -ease with which the lungs can be inflated
What is lung distensibility increased in? - correct-answer -neonates and children;
emphysema
What is lung distensibility decreased in? - correct-answer -elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
What is surfactant? - correct-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
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What produces surfactant? - correct-answer -produced by the Type II alveolar cells
What is Ohm's law? - correct-answer -velocity = driving force/resistance
What is Poiseuille law? - correct-answer -resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? - correct-answer -the resistance goes up
How is the ventilation distributed in the lungs? - correct-answer -the top of the lungs are more
distended and less compliant whereas the lower lung is small and highly compliant
What factors affect lung perfusion? - correct-answer -lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
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What does hypoxia lead to? - correct-answer -vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? - correct-answer -pulmonary hypertension
What factors affect alveolar-capillary diffusion? - correct-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? - correct-answer -acidemia;
hyperthermia;
hypercarbia
What causes left shifts (increased affinity) in Hemoglobin-O2 affinity? - correct-answer -alkalemia;
hypothermia;
hypocarbia
What is hypoxemia? - correct-answer -deficient blood oxygen;
low PaO2;
NUR 242 MED SURG EXAM 3| CERTIFIED
QUESTIONS WITH ANSWERS 2026
What is ventilation? - correct-answer -the movement of air into and out of the lungs
What is perfusion? - correct-answer -the circulation of blood through the lungs
What are central chemoreceptors responsive to? - correct-answer -increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? - correct-answer -decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces? - correct-answer -lungs recoil due to elastin, collagen, fibrin
,2|Page
What are surface forces? - correct-answer -surface tension due to water-air interface
What is airway resistance? - correct-answer -opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? - correct-answer -ease with which the lungs can be inflated
What is lung distensibility increased in? - correct-answer -neonates and children;
emphysema
What is lung distensibility decreased in? - correct-answer -elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
What is surfactant? - correct-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
,3|Page
What produces surfactant? - correct-answer -produced by the Type II alveolar cells
What is Ohm's law? - correct-answer -velocity = driving force/resistance
What is Poiseuille law? - correct-answer -resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? - correct-answer -the resistance goes up
How is the ventilation distributed in the lungs? - correct-answer -the top of the lungs are more
distended and less compliant whereas the lower lung is small and highly compliant
What factors affect lung perfusion? - correct-answer -lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
, 4|Page
What does hypoxia lead to? - correct-answer -vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? - correct-answer -pulmonary hypertension
What factors affect alveolar-capillary diffusion? - correct-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? - correct-answer -acidemia;
hyperthermia;
hypercarbia
What causes left shifts (increased affinity) in Hemoglobin-O2 affinity? - correct-answer -alkalemia;
hypothermia;
hypocarbia
What is hypoxemia? - correct-answer -deficient blood oxygen;
low PaO2;
