7. COMPOSITION AND PARTIAL PRESSURE OF RESPIRATORY GASES: MAN 

 Values in parentheses conform to estimate "d" of the 95% range (cf Introduction). 



Ventilated Gas 



HI Dry air. Partial pressure in mm Hg = vol %/ 100 x 760 mm Hg (Dalton's law), /2/ Ambient air; slight varia- 

 tions exist. Vol % = 100 X (partial pressure in mm Hg)/760 mm Hg (Dalton's law). /3/ "Alveolar" air, actually 

 last part of expired samples. /4/ Physiological air, normal temperature (37°C), and standard pressure (760 mm 

 Hg). /5/ Variable, depending on blood flow, tissue activity and relation of sample to capillary length or field. 

 /6/ Internal jugular. 

 Contributor : (a) McCutcheon, F. H. 



References : [ 1] Krogh, A., "The Comparative Physiology of Respiratory Mechanisms, " Philadelphia: Univ. of 

 Pennsylvania Press, 1941. [2] Nims, L. F., in Fulton's "Textbook of Physiology, " Philadelphia: W. B. Saunders 

 Co., 1949. [3] Albritton. E. C "Standard Values in Blood, " Philadelphia: W. B. Saunders Co., 1952 (average 

 from Table 67). [4] Albritton, E. C, "Standard Values in Blood, " Philadelphia: W. B. Saunders Co., 1952 

 (average from Table 94). [5] Albritton, E. C, "Standard Values in Blood, " Philadelphia: W. B. Saunders Co., 

 1952 (average from data for plasma, Table 94). 



8. PRESSURE- DEPTH GRADIENT IN THE SEA 



Hydrostatic pressure increases with depth at approximately 0.1 atmosphere per meter, the exact value being affected 

 by salinity, temperature and latitude of the water. Salinity is expressed in parts per thousand (°/oo). 



/I/ 1 atmosphere • 1.01325 bars. 1.03327 kg/sq cm, 14.696 Ib/sq in. 760 mm Hg. 

 Contributor : ZoBell, C. E. 



9. PRESSURE EQUIVALENTS 



Contributor: Behnke, A. R. 



