NUR 242 MED SURG EXAM 3 LATEST ACTUAL
COMPREHENSIVE QUESTIONS AND SOLUTIONS
2026 STUDY GUIDE
⩥ 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
⩥ What is anemic hypoxia?. Answer: decreased tissue oxygen caused by
decreased hemoglobin
COMPREHENSIVE QUESTIONS AND SOLUTIONS
2026 STUDY GUIDE
⩥ 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
⩥ What is anemic hypoxia?. Answer: decreased tissue oxygen caused by
decreased hemoglobin
