THE CIRCULATION OF THE BLOOD 705 



to excitation, or excitation to inhibition, respectively, on the vasomotor reflexes. 

 Owing to the complex nature of these reflexes effects are sometimes produced of 

 a nature difficult at first to analyse. 



The effect of products of metabolism of active organs is to cause dilatation of 

 the blood vessels, thus ensuring an automatic regulation of blood supply. But 

 the facts do not account for the whole of the vaso dilator phenomena met with, 

 which require the existence of vaso-dilator or inhibitory nerves. 



The reflex secretion of adrenaline is not necessary as an accompaniment of 

 pressor reflexes, so that we require also the existence of a vaso-constrictor centre. 



There is some evidence that the muscular wall of the arterioles responds to 

 stretching by a contraction, but the question is not yet definitely decided. 



The coagulation of the blood is an interaction between certain colloidal 

 systems under the influence of electrolytes, chiefly calcium salts. The intervention 

 of surface action is shown by the accelerating effect of rough surfaces and by the 

 action of lipoids. 



LITERATURE 

 HEART. 



General. 



Starling (1912, pp. 1004-1033, 10V7-1098). 



Energetics. 



Rohde and Nagasaki (1913). 

 Lovatt Evans (1914, 1). 

 Patterson and Starling (1914). 

 Patterson, Piper, and Starling (1914). 



Nature of Beat. 



Gaskell (1900). 



Pace-Maker. 



Thos. Lewis (1913, 3). 



Anatomy of His' Bundle. 

 Tawara (1906). 



Nervous Mechanism. 

 Gaskell (1882). 



Bayliss and Starling (1892, 2). 

 Mines (1914, 1). 



BLOOD VESSELS. 



Flow through Tubes. 



Tigerstedt (1893, pp. 304-321). 



Vascular Reflexes. 



Bayliss (1908, 2 and 3). 



Regulation of Blood Flow. 

 Bayliss (1906, 3). 



Coagulation of the Blood, 

 Nolf (1906-7, 1908). 



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