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NUR 242 MED SURG EXAM 3 UPDATED
ACTUAL EXAM WITH CORRECT VERIFIED
SOLUTIONS
What are central chemoreceptors responsive to? - correct
answer- increased H+ in the brain ECF; increased
PaCO2;
"hypercarbic drive"
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 peripheral chemoreceptors responsive to? - correct
answer- decreased pH; increased PaCO2; decreased PaO2;
"hypoxic drive"
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What are elastic forces? - correct answer- lungs recoil due to
elastin, collagen, fibrin
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
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throughout the lungs, thereby contributing to its general
compliance;
stabilizes the alveoli and keeps them dry
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
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What factors affect lung perfusion? - correct answer- lung
capacitance; low resistance system; flow influenced by
gravity;
resistance primarily determined by vessel radius
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
NUR 242 MED SURG EXAM 3 UPDATED
ACTUAL EXAM WITH CORRECT VERIFIED
SOLUTIONS
What are central chemoreceptors responsive to? - correct
answer- increased H+ in the brain ECF; increased
PaCO2;
"hypercarbic drive"
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 peripheral chemoreceptors responsive to? - correct
answer- decreased pH; increased PaCO2; decreased PaO2;
"hypoxic drive"
,2 | Page
What are elastic forces? - correct answer- lungs recoil due to
elastin, collagen, fibrin
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
,3 | Page
throughout the lungs, thereby contributing to its general
compliance;
stabilizes the alveoli and keeps them dry
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
, 4 | Page
What factors affect lung perfusion? - correct answer- lung
capacitance; low resistance system; flow influenced by
gravity;
resistance primarily determined by vessel radius
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
