NUR242 EXAM 3 2026 CERTIFICATION TEST
QUESTIONS AND ANSWERS UPDATED
◉ 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"
◉ 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
◉ 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
◉ 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
◉ What causes left shifts (increased affinity) in Hemoglobin-O2
affinity? Answer: alkalemia;
hypothermia;
hypocarbia
◉ What is hypoxemia? Answer: deficient blood oxygen;
low PaO2;
low O2 saturation
◉ What is hypoxia? Answer: decreased tissue oxygen
◉ What is hypoxic hypoxia? Answer: decreased tissue oxygen
caused by decreased respirations
QUESTIONS AND ANSWERS UPDATED
◉ 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"
◉ 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
◉ 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
◉ 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
◉ What causes left shifts (increased affinity) in Hemoglobin-O2
affinity? Answer: alkalemia;
hypothermia;
hypocarbia
◉ What is hypoxemia? Answer: deficient blood oxygen;
low PaO2;
low O2 saturation
◉ What is hypoxia? Answer: decreased tissue oxygen
◉ What is hypoxic hypoxia? Answer: decreased tissue oxygen
caused by decreased respirations
