Respiratory System
If the pressure between the visceral pleura of the lungs and the parietal pleura of the thoracic cage is −6 mm Hg, then:
The lung will collapse.
Exhalation is occurring.
The pressure is above atmospheric pressure.
The lungs will fill with air.
The lungs will fill with air.
The intra-pleural pressure must be negative (=below atmospheric pressure) if the lungs are to expand as the chest wall expands. It oscillates between about −2 mmHg (−270 Pa) when inhalation is about to begin and about −6 mmHg (−800 Pa) when inhalation has ended and exhalation is about to occur. Hence, a value of ~6 mmHg indicates that inhalation is occurring.
The lungs will fill with air. The intra-pleural pressure must be negative (=below atmospheric pressure) if the lungs are to expand as the chest wall expands. It oscillates between about −2 mmHg (−270 Pa) when inhalation is about to begin and about −6 mmHg (−800 Pa) when inhalation has ended and exhalation is about to occur. Hence, a value of ~6 mmHg indicates that inhalation is occurring.
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B. 43 mm Hg
C. 46 mm Hg
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B. 104 mmHg
C. 79 mmHg
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Which of the following buffer systems of the body is affected by the action of the lungs?
A. Protein
B. Monohydrogen phosphate/dihydrogen phosphate
C. Ammonia/ammonium
D. Carbonic acid/bicarbonate
Which molecule or ion dissolved in blood is able to stimulate the central chemoreceptors of the brain’s respiratory centre?
A. CO2
B. H3O+
C. O2
D. Ca2+
Which of the following lists the components of the respiratory membrane?
A. Alveolar epithelial cells, capillary endothelial cells and their basement membranes
B. Fluid and surfactant alveolar epithelial cells, capillary endothelial cells and their basement membranes
C. Visceral pleura, parietal pleura and serous fluid
D. Ciliated epithelial cells, mucus cells and secreted mucus
If the partial pressure of oxygen in the air contained in the alveoli of the lungs is 14 kPa, then the partial pressure of oxygen dissolved in the alveolar fluid will be:
A. Very close to 14 kPa
B. Significantly greater than 14 kPa
C. Significantly less than 14 kPa
D. Unable to be determined without the solubility coefficient of oxygen and the temperature of the alveolar fluid
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