(GALEN)NUR 242 Med Surg Exam 3questions and
answers
What is ventilation? - ✔✔ANS the movement of air into and out of
the lungs What is perfusion? - ✔✔ANS the circulation of blood
through the lungs
What are central chemoreceptors responsive to? - ✔✔ANS increased H+ in the
brain ECF; increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? - ✔✔ANS
decreased pH; increased PaCO2;
decreased
PaO2; "hypoxic
drive"
What are elastic forces? - ✔✔ANS lungs recoil due to elastin,
collagen, fibrin What are surface forces? - ✔✔ANS surface tension
due to water-air interface
What is airway resistance? - ✔✔ANS opposition to flow caused by the forces of
friction; primarily determined by airway radius
What is the distensibility of the lungs? - ✔✔ANS ease with which the lungs
can be inflated What is lung distensibility increased in? - ✔✔ANS neonates
,and children;
emphysema
,What is lung distensibility decreased in? - ✔✔ANS
elderly; pneumonia, pulmonary edema, ARDS,
atelectasis, fibrosis
What is surfactant? - ✔✔ANS 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? - ✔✔ANS produced by the Type II
alveolar cells What is Ohm's law? - ✔✔ANS velocity = driving
force/resistance
What is Poiseuille law? - ✔✔ANS resistance = (8 x viscosity x length) / (pi x
radius^4) What happens if the radius in the lungs goes down? - ✔✔ANS
the resistance goes up
How is the ventilation distributed in the lungs? - ✔✔ANS 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? - ✔✔ANS lung
capacitance; low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? - ✔✔ANS vasoconstriction of
pulmonary vessels What does prolonged hypoxia lead to? -
✔✔ANS pulmonary hypertension
What factors affect alveolar-capillary diffusion? - ✔✔ANS capillary
permeability; surface area available for diffusion;
, concentration gradient for
the gas; distance for
diffusion
answers
What is ventilation? - ✔✔ANS the movement of air into and out of
the lungs What is perfusion? - ✔✔ANS the circulation of blood
through the lungs
What are central chemoreceptors responsive to? - ✔✔ANS increased H+ in the
brain ECF; increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? - ✔✔ANS
decreased pH; increased PaCO2;
decreased
PaO2; "hypoxic
drive"
What are elastic forces? - ✔✔ANS lungs recoil due to elastin,
collagen, fibrin What are surface forces? - ✔✔ANS surface tension
due to water-air interface
What is airway resistance? - ✔✔ANS opposition to flow caused by the forces of
friction; primarily determined by airway radius
What is the distensibility of the lungs? - ✔✔ANS ease with which the lungs
can be inflated What is lung distensibility increased in? - ✔✔ANS neonates
,and children;
emphysema
,What is lung distensibility decreased in? - ✔✔ANS
elderly; pneumonia, pulmonary edema, ARDS,
atelectasis, fibrosis
What is surfactant? - ✔✔ANS 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? - ✔✔ANS produced by the Type II
alveolar cells What is Ohm's law? - ✔✔ANS velocity = driving
force/resistance
What is Poiseuille law? - ✔✔ANS resistance = (8 x viscosity x length) / (pi x
radius^4) What happens if the radius in the lungs goes down? - ✔✔ANS
the resistance goes up
How is the ventilation distributed in the lungs? - ✔✔ANS 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? - ✔✔ANS lung
capacitance; low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? - ✔✔ANS vasoconstriction of
pulmonary vessels What does prolonged hypoxia lead to? -
✔✔ANS pulmonary hypertension
What factors affect alveolar-capillary diffusion? - ✔✔ANS capillary
permeability; surface area available for diffusion;
, concentration gradient for
the gas; distance for
diffusion
