Two human disorders, Prader-Willi syndrome and Angelman syndrome, occur when a small deletion in a specific region of chromosome 15 is contributed by either the father or mother, respectively. Why does this small deletion not behave as a recessive allele for either syndrome, that is, why is its loss not made up for by the good copy of the region on chromosome 15 contributed by the other parent?

#Question id: 11059

#Unit 7. System Physiology – Animal

A healthy, 45-year-old man is reading the newspaper. Which of the following muscles are used for quiet breathing?

#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?