NURS 242 Exam 3 NEWEST EXAM 2025-2026 ALREADY
GRADED A+ BY EXPERTS PASS!
What is perfusion?
ANSWERS; the circulation of blood through the lungs
What are central chemoreceptors responsive to?
ANSWERS; increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to?
ANSWERS; decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces?
ANSWERS; lungs recoil due to elastin, collagen, fibrin
,What are surface forces?
ANSWERS; surface tension due to water-air interface
What is airway resistance?
ANSWERS; opposition to flow caused by the forces of friction; primarily
determined by airway radius
What is the distensibility of the lungs?
ANSWERS; ease with which the lungs can be inflated
What is lung distensibility increased in?
ANSWERS; neonates and children;
emphysema
What is lung distensibility decreased in?
ANSWERS; elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
,What is surfactant?
ANSWERS; 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?
ANSWERS; produced by the Type II alveolar cells
What is Ohm's law?
ANSWERS; velocity = driving force/resistance
What is Poiseuille law?
ANSWERS; resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down?
, ANSWERS; the resistance goes up
How is the ventilation distributed in the lungs?
ANSWERS; 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?
ANSWERS; lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to?
ANSWERS; vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to?
ANSWERS; pulmonary hypertension
GRADED A+ BY EXPERTS PASS!
What is perfusion?
ANSWERS; the circulation of blood through the lungs
What are central chemoreceptors responsive to?
ANSWERS; increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to?
ANSWERS; decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces?
ANSWERS; lungs recoil due to elastin, collagen, fibrin
,What are surface forces?
ANSWERS; surface tension due to water-air interface
What is airway resistance?
ANSWERS; opposition to flow caused by the forces of friction; primarily
determined by airway radius
What is the distensibility of the lungs?
ANSWERS; ease with which the lungs can be inflated
What is lung distensibility increased in?
ANSWERS; neonates and children;
emphysema
What is lung distensibility decreased in?
ANSWERS; elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
,What is surfactant?
ANSWERS; 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?
ANSWERS; produced by the Type II alveolar cells
What is Ohm's law?
ANSWERS; velocity = driving force/resistance
What is Poiseuille law?
ANSWERS; resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down?
, ANSWERS; the resistance goes up
How is the ventilation distributed in the lungs?
ANSWERS; 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?
ANSWERS; lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to?
ANSWERS; vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to?
ANSWERS; pulmonary hypertension
