Respiratory Unit 5

Question 1

conducting zone

Answer 1

includes the organs and structures not directly involved in gas exchange

Question 2

respiratory zone

Answer 2

gas exchange occurs

Question 3

pharynx

Answer 3

a tube formed by skeletal muscle and lined by mucous membrane that is continuous with that of the nasal cavities
1.nasopharynx
2.oropharynx
3. laryngopharynx

Question 4

Atmospheric pressure

Answer 4

pressure of the air in the atmosphere. This pressure changes with altitude. At sea level it is 760 mmHg, but we call it zero so we can speak in terms of relative pressures regardless of altitude.

Question 5

Trans-pulmonary pressure

Answer 5

collapsing pressure or the recoil pressure of the lungs due to surfactant and elastic properties. Constant at +4

Question 6

Intra-pleural pressure

Answer 6

pressure within the pleural cavity due to the fluid bond between the visceral and parietal pleura and the parietal pleura’s adhesion to the body wall and diaphragm. The fluid bond is the surface tension created by the pleural fluid. Intra-pleural pressure can also be thought of as the expanding pressure of the lung. This pressure is variable from -2 (controlled recoil during exhalation) to -6 (expansion of the lung during inhalation).

Question 7

Intra-pulmonary pressure / Alveolar pressure

Answer 7

pressure of the air within the alveoli. Varies about -2 to +2 and is the net pressure between trans-pulmonary pressure and intra-pleura pressure. On average it’s the same as atmospheric pressure. This is the pressure that drives air in (-) and out (+) of the lungs. The graph in your worksheet shows -1 to +1.