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DISEASES OF THE HEART IN DOMESTIC ANIMALS. 217 
The action of the heart is no doubt dependent upon the central 
part of the nervous system. However, other nerve motors exist for 
it also for, after total destruction of the spinal cord and the 
brain the action continues for some time if the respiration be 
artificially maintained. Furthermore, it is remarkable that the 
destruction of the superior ganglion, the sympathetics and the 
thoracic walls do not cause the heart to stop immediately. 
It is generally admitted that the precise rhythm in the move¬ 
ments of the seperate apartments of the heart is dependent upon 
the intra-carotid ganglion in the small nervous parts, which are 
contained in the muscles of the heart. The latter in particular 
are to be found in the partition wall of the auricle and on the at¬ 
tached parts of the auriculo-ventricular valves. 
The regulation of the rhythm seems to be arranged in such a 
manner by checking and accelerating mechanism, that it attains 
its activity periodically in definite rhythms. The regulated in¬ 
fluence upon the rhythm and the force of the heart’s action is at¬ 
tained by means of the plexus of the heart over the branches of 
the nerves of the lungs and the sympathetics. The outpouring 
and inpouring of the blood in the vessels in the human being 
gives positive proof of the correctness of my assertion. Division of 
the pneumo-gastric nerve causes acceleration of the heart’s action, 
an irritation of the same nerve causes a retardation of it at its peri¬ 
pheric end. A violent excitement of the peripheric end of the 
pneuino-gastric nerve after its division causes the heart during 
diastole to come to a complete standstill (conf. Muller 1. c.). The 
pneumo-gastric nerves are therefore in reference to the heart’s 
action, inhibitory nerves, have a retarding and regulating effect 
upon the heart, inasmuch as they to some extent regulate and 
keep in motion the action which was released from the intra-caro¬ 
tid ganglion. Excitement of the sympathetic nerve results in the 
quickening the action of the heart and can be brought to action 
again even where it is already extinct. 
(To be continued .) 
