GASES OF VENOUS BLOOD, 



763 



to corresponding variations in its gaseous constituents. It is therefore 

 only possible to give a mean value for the gases of the venous blood 

 when the analyses are performed upon samples removed from the right 

 ventricle ; this procedure can be carried out by passing a catheter from 

 the right external jugular vein through the right auricle and into the 

 right ventricle. The following table gives the results of the few experi- 

 ments of this kind, together with the data of simultaneous analyses of 

 the arterial blood : 



The effect of different conditions on the gases of venous Hood, It has 

 already been mentioned that the venous blood is liable to marked 

 differences in its gaseous contents, according to the condition of the 

 organs from which the blood is received. 



The venous blood leaving a muscle varies according to the condition 

 of the tissues 6 ; when the muscle is actively contracting, the percentage 

 of oxygen in the blood is much diminished, and the amount of carbon 

 dioxide is increased, notwithstanding the increase in the volume and 

 velocity of the circulating blood. The experiments of Bernard 7 and 

 Zuntz 8 show that, after section of the motor nerve, the absorption of 

 oxygen and the production of carbon dioxide in the muscle are much 



1 Sitzungsb. d. k. Akad. d. Wissemck. Math.-naturw. CL, Wien, 1860, Bd. xli. 

 S. 589. 



2 " La pression barometrique, " Paris, 1878, p. 1038. 



3 Arch.f. d, ges. Physiol., Bonn, 1873, Bd. vii. S. 575. 



4 Ibid., 1875, Bd. x.'S. 368. 



5 Compt. rend. Acad. d. sc., Paris, 1872, tome Ixxiv. p. 190. 



G Sczelkow, Sitzungsb. d. k. Akad. d. Wissensch., Wien, 1862, Bd. xlv. S. 171; 

 Mathieu and Urbain, Compt. rend. Acad. d. sc., Paris, 1872, tome Ixxiv. p. 190 ; Bernard, 

 "Lecons sur la chaleur animale," Paris, 1876, p. 147; Zuntz, Berl. klin. Wchnschr., 

 1878J No. 10, S. 141 ; von Frey, Arch.f. Physiol., Leipzig, 1885, S. 533; Chauveau and 

 Kaufmaim, Compt. rend. Acad. d. sc., Paris, 1886, tome ciii. pp. 974, 1057, 1153 ; Hill and 

 Nabarro, Journ. Physiol., Cambridge and London, 1895, vol. xviii. p. 218. 



7 Loc. cit. 8 Loc. cit. 



