328 Physiologie der Zellen, Gewebe und Organe. 



for the maintenance of a certain semi-permeability essential for the heart to 

 function. Min es. 



831) Krogh, A. and Lindhard, J.," The regulation of respiration and 

 circulation during the initial stages of muscular work. In: Journ. of 

 PhysioL, Bd. XLVH, S. 112, 1913. 



At the beginning of heavy work — especially in persons trained to sudden 

 and violent exertions — there is an abrupt rise in pulmonary Ventilation and 

 heart rate. The blood flow (as indicated by the absorption of Og in the lungs) 

 is increased evenly but very rapidly. The Ventilation then falls somewhat during 

 8 — 12" and then rises again. There is a primary fall in the tension of alveolar 

 COg. The respiratory quotient rises to or above unity. — The incrfeased Venti- 

 lation is due to Irradiation of impulses from the motor cortex, which increase the 

 excitability of the respiratory centre towards hydrogen ions. Min es. 



832) Patterson, S. W. and Starling, E. H., The carbohydrate metabo- 

 lism of the isolated heart lung preparation. In: Journ. of PhysioL, 

 Bd. XL VII, S. 137, 1913. 



Repetition of the experiments of Kno wlton and Starling on consumption 

 of sugar by the heart, with a number of improvements in technique fail to show 

 that the heart of the depancreatised dog is less capable of consuming sugar than 

 the normal heart. The authors abandon the view that the essential factor in dia- 

 betes is the absence of power on the part of the tissues to consume sugar. 



Mines. 



833) Fühuer, H. and Starling, E. H., Experiments on the pulmonary 

 circulation. In: Journ. of PhysioL, Bd. XL VII, S. 286, 1913. 



On an average the pulmonary arterial pressure is about Yg that of the sy- 

 stemic arterial pressure. A rise of systemic blood pressure causes dilatation and 

 increased volume of the heart, a proportional rise of pulmonary arterial pressure 

 and a rise in pressure of left auricle and inferior vena cava. In asphyxia, if the 

 arterial resistance is kept constant, the aortic pressure falls as the heart falls, 

 while there is a rise of pressure in the pulmonary artery, vena cava and left auricle. 

 Similar effects are produced by Inhalation of COj. Adrenalin causes diminished 

 volume of the heart, a rise of pressure in the pulmonary artery and fall in the 

 left auricle. Adrenalin therefore causes contraction of the blood vessels in the 

 lungs. Mines. 



834) Krogh, A. and Lindhard, J., The volume of the "dead space" in 

 breathing. In: Journ. of PhysioL, Bd. XL VII, S. 30—43, 1913. 



The conclusion of Douglas and Haidane that the "dead space" is greatly 

 increased during muscular work rested on a faulty experimental method. Sie- 

 beck 's method, of inspiring a known volume of hydrogen and determining its 

 distribution in successive expirations avoids the most serious errors which arise 

 from the use of the direct method of analysing samples taken at the end of ex- 

 piration and of inspiration. The effective dead space in breathing is not appre- 

 ciably altered during heavy muscular work. Mines. 



835) Vernon, H. M., The auto-catalysis of trypsinogen. In: Journ. of PhysioL 

 XLVII, S. 325, 1913. 



Freshly formed trypsin is very active in transforming trypsinogen into trypain. In 

 the Bmall intestine the activation of pancreatic juice is initiated by enterokinase but 

 is for the most part an autocatalytic process. Mines. 



