8 PEINCIPLES OF VETEBIKAEY SUBGEKY 



forms, also retraction and contraction of tke cut end of 

 the vessel. When a large blood-vessel is cut, spontaneous 

 arrest of hemorrhage is due to retraction and contraction 

 and thrombus formation at the cut end plus enfeebled heart 

 action and changed composition of the blood. 



Why does spontaneous arrest of hemorrhage in small vessels 

 readily occv/r ? 

 Because blood pressure is very limited in capillaries 

 and small veins, thus favoring the formation of a clot 

 (thrombus). 



IIow does the changed composition of the Hood following 

 serious bleeding encourage clot formation ? 

 The changed composition of the blood mainly consists in 

 a decided increase of tLo "white blood cells, by -which its 

 coagulability is greatly increased. 



How m.uch blood may an animal lose before succumbing to 

 fatal cardiac or cerebral syncope 9 

 Not over one-third of the total amount of blood. 



H.OW quickly does the blood regenerate after a hemorrhage? 

 The quantity of the blood is quite speedily replaced by 

 resorption of the lymph of the tissues and the liquids of the 

 stomach and intestines ; the quality of the' blood is at first 

 very watery, regeneration of the red blood cells being a slow 

 process. 



How is a thrombus formed ? 



There are two kinds, the white and the red thrombus. 

 The former is met with in the healthy animal, the latter is 

 seen in septic states. At the same time both may exist 

 together, and the thrombus is then termed a mixed thrombus. 



