546 PHYSICAL EXAMINATION OF THE CmCULATORY ORGANS. 



traceable to structural changes, and believed to be intimately 

 connected with constitutional causes, with peculiar states of 

 the blood, or with functional impairment of the heart itself, 

 and named inorganic or functional oimrmurs. 



These murmurs or bellows-sounds being essentially con- 

 nected with the great valvular orifices of the heart, we can 

 easily understand how each orifice may be the seat of two 

 distinct murmurs — (1) Constrictive ; (2) Regurgitative. One 

 with the current, one against it ; the blood in the one instance 

 not being allowed a free passage, in the other not being effec- 

 tually prevented from returning. In this way eight miu-murs 

 only are possible. As I do not, however, believe that with the 

 horse it is possible to separate and differentiate these eight 

 distinct possible morbid sounds, it is scarcely worth wasting 

 time in going through them in detail; but I will merely 

 mention shortly those we most commonly encounter, and 

 of the existence of which I believe it is in many cases possible 

 to satisf}'- ourselves. 



a. Probably the most frequently encountered and most pro- 

 nounced of these bellows-murmurs is that which may be heard 

 accompanying, or immediately following, or sliding away from 

 the first sound — the ventricle systole, and hence called 'a 

 ventricular systolic murmur.' 



This, as will be understood, may have its origin either in 

 the auriculo-ventricular or in the arterial orifices. If in the 

 auriculo-ventricular, it is a murmur of regurgitation ; if m the 

 arterial opening, it is a murmur of obstruction. This sound 

 may thus be indicative of insufficiency, or disease of the mitral 

 valve; disease of the aortic valvular opening, either constrictive 

 or the result of endocardial roughness ; also from collections of 

 fibrinous coagula amongst the chordae tendinere. 



This is ordinarily a murmur of considerable intensity ; it is 

 high-pitched and prolonged, particularly so when associated, 

 as it sometimes is, with hypertrophy of the ventricle. Its 

 existence has been most frequently noticed by me in cases of 

 insufficiency of the mitral valve consequent upon hypertrophy 

 with dilatation. It will also be heard in those instances where, 

 although insufficiency does not exist, there is yet disease of 

 the ventricular surface of the valve, generally in the form of 

 puckering and thickening of the endocardial membrane of the 



