Tryptophan, the end-product of the enzymes encoded by the trp operon, therefore acts as a co-repressor and inhibits its own synthesis through:

#Question id: 11073

#Unit 7. System Physiology – Animal

The respiratory passageways have smooth muscle in their walls. Which of the following best describes the effect of acetylcholine and epinephrine on the respiratory passageways?

#Question id: 11069

#Unit 7. System Physiology – Animal

A 22-year-old woman inhales as much air as possible and exhales as much air as she can producing the spirogram shown in the figure. A residual volume of 1.0 L was determined using the helium dilution technique. What is her functional residual capacity (in liters)?

#Question id: 11067

#Unit 7. System Physiology – Animal

A preterm infant has a surfactant deficiency. Without surfactant, many of the alveoli collapse at the end of each expiration, which in turn leads to pulmonary failure. Which of the following sets of changes are present in the preterm infant, compared to a normal infant?

#Question id: 11064

#Unit 7. System Physiology – Animal

The diagram above shows three different compliance curves (S, T, and U) for isolated lungs subjected to various transpulmonary pressures. Which of the following best describe the relative compliances for the three curves?

#Question id: 10879

#Unit 7. System Physiology – Animal

If the inspiratory reserve volume is 3000 mL, the tidal volume is 500 mL, the expiratory reserve volume is 1000 mL, and the residual volume is 1000 mL, what is the vital capacity?

#Question id: 10877

#Unit 7. System Physiology – Animal

A 27-year-old man is breathing quietly. He then inhales as much air as possible and exhales as much air as he can, producing the spirogram shown in the previous figure. What is his expiratory reserve volume (in liters)?