The tracheal (respiratory) system in Drosophila embryos develops from epithelial sacs. The approximately 80 cells in each of these sacs become reorganized into primary, secondary, and tertiary branches without any cell division or cell death. This reorganization is initiated when nearby cells secrete a protein called Branchless, which acts as a:

#Question id: 11060

#Unit 7. System Physiology – Animal

A healthy, 25-year-old medical student participates in a 10-km charity run for the American Heart Association. Which of the following muscles does the student use (contract) during expiration?

#Question id: 11061

#Unit 7. System Physiology – Animal

The pleural pressure of a normal 56-year-old woman is approximately −5 cm H2O during resting conditions immediately before inspiration (i.e., at functional residual capacity). What is the pleural pressure (in cm H2O) during inspiration?

#Question id: 11062

#Unit 7. System Physiology – Animal

The alveolar pressure of a normal 77-year-old woman is approximately 1 cm H2O during expiration. What is the alveolar pressure during inspiration (in cm H2O)?

#Question id: 11063

#Unit 7. System Physiology – Animal

A man inspires 1000 ml from a spirometer. The intrapleural pressure was −4 cm H2O before inspiration and −12 cm H2O the end of inspiration. What is the compliance of the lungs?

#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: 11065

#Unit 7. System Physiology – Animal

A liquid-ventilated lung compared to a gas-ventilated lung