Respiratory Practice Exam

D is correct because RQ = CO2 produced / O2 consumed
A is incorrect because it refers to the amount of CO2 produced
B is incorrect because an RQ of .7 would indicated a diet of only fats. A diet of only carbohydrates would be ~ 1.0
C is incorrect because the RQ actually drops as you increase your fat intake
E is incorrect because the value changes depending on diet and metabolic demand

B is correct
A is wrong because the respiratory zone has no smooth muscle
C is wrong because bronchoconstriction deals with smooth muscle not with alveolar sacs.
D is wrong because reistance in the airways actually INCREASES with bronchoconstriction
E is wrong because the diffusion of respiratory gases occurs
in the respiratory zone at the alveoli. Bronchoconstriction does not occur at this location

B is correct because the upper airways of the conducting zone contain ciliated cells and mucus-secreting cells.
A is incorrect because the conducting airways contain smooth muscle
C is incorrect because the respiratory bronchioles are part of the respiratory zone
D is incorrect because it is type II cells that secrete surfactant and furthermore they are found within the alveoli which are not part of the conducting zone
E is incorrect because the conducting zone has no capacity to senst the atmoshperic oxygen concentration

E is correct because the presence of carbon monoxide would decrease the affinity of Oxygen to bind to Hb
A is incorrect because an increase in surface are of the lung would actually INCREASE the rate of diffusion
B is incorrect because an increase in the concentration gradient would also likewise INCREASE the rate of diffusion
C is incorrect because it should say an INCREASE in the thickness of the membrane to be true
D is a junk answer. Hb is always present in the red blood cell

D is correct
A is incorrect because Surfactant DECREASES surface tension
B is incorrect because it is Type II cells that secrete surfactant
C is incorrect because it prevents collapse
E is incorrect because it does not occur in the intrapleural space

A is correct because Surfactant decreases the surface tension and thereby increases the compliance of the Lung. Premature infants often lack adequate secretion of surfactant
B is incorrect because compliance varies with the size of the lung and therefore also with the volume of the lung
C is incorrect because at RV or TLC the compliances are actually low and we rarely fill our lungs to tlc because of the very high energy cost
D is wrong because Emphysema actually INCREASES the Compliance--unfortunately this increase makes the peripheral airway diameters more dependent on extra-alveolar pressures and may create a Starling resistor which causes resistance to airflow
E is incorrect because FRC changes with Compliance. For example as compliance decreases it tends to reduce the FRC as well

A is correct
B is incorrect because to be at rest alveolar pressure must be equal to atmospheric pressure
C is incorrect because if alveolar pressure were subatmospheric the pressure gradient would cause INSPIRATION
D is incorrect because the pleural pressure is usually around -4 mm Hg and alveolar is usually around 100 mm Hg

VA =RF (VT-VDS)
=20 (700-200)
=10,000 ml
=10 L

Blood flow is to the alveoli is usually greater at the base of the lung due to gravity. However, if you turn a person upside down the majority of the blood flow will be at the apex and therefore respiration will depend on the apex more for diffusion of gases. the diffusion of gases required high surface area (as well as a concentration gradient and thin wall)

D is correct
A and B are incorrect because the external intercostal muscles and the diaphragm activate during INSPIRATION
The muscles used for forced expiration are the abdominal muscles and the internal intercostals. D is the only option

see notes on group discussion

Remember the curve shifts to the right with an increase in the following values (CO2, [H+], Heat, 2,3-BPG)

you better know this one

accessory muscles are innervated by CN 11 and the diaphram by the phrenic nerve (C3,4,5) These would still be intact after a T1 transection. all other muscles such as the intercostals and abdominals would be wiped out

A is correct
B is incorrect because increased hemoglobin concentrations has no affect on the % Hb saturation
C is incorrect becaus it is 10% of CO2 that is transported in the dissolved form--O2 is much less than that I beleive
D is incorrect because the reverse is true
E is incorrect becase the arterial PCO2 is normally about 40, 46 is a tad high

C is correct
A is incorrect because the pleural pressure at the apex is more negative than that at the base
B is incorrect because FRC is defined when all muscles are relaxed
D is incorrect because the question asked about distendability not resistance to airflow

E is correct because during inspiration regardless of excercise the pressure must be greater in the mouth than it is in the alveoli in order to create a gradient for air flow. Also the pleural pressure is negative and there for less than atmospheric pressure and alveolar pressure. E is the only choice that accounts for these conditions