VAPILLART SYSTEMS. 145 



Q. Why is it, that while the capillary tubes are free 

 and every where open, the blood does not pass into all? 



A. A general physiological reply may serve, viz. that 

 the organic sensibility of different organs admits certain 

 matters, and rejects all others. Such is the case with the 

 trachea and lacteals, and many others. 



Q. How then is there an occasional increased flow of 

 blood to a part? 



#. Irritation applied to that part, increases the organic 

 sensibility, and thus more blood appears in, or is invited 

 to it. 



Q. What is the great difference between organized and 

 inert tubes or vessels? 



*#. The vitality of the organized, and the inert being 

 under the influence solely of mechanical laws. 



Q. Where is it that organic sensibility varies most, and 

 thus affects the course of the blood? 



/?. This takes place in the capillary system ; not in the 

 large vessels. 



Of Inflammation. 



Q. What is the first step in the pathology of inflam- 

 mation ? 



#. An alteration and increase of the organic sensibility, 

 in consequence of an irritant to the part. 



Q. How is this local irritation produced? 



<fl. By direct irritation, or by organic continuity, or by 

 sympathy. 



Q. What is the second step in the process of inflam- 

 mation? 



t#. An irritation of blood by the increased organic sen- 

 sibility, and a remora of blood while irritation continues. 



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