Physiology and biochemistry in modern medicine . ere this takes place. If the heart isexcised, hoAvever, it will continue to beat for a feAv moments, and as itdies it will be observed that the poAver of contraction remains in the au-ricular region, and particularly at the bases of the vena? cava?, for a con-siderable time after the ventricles have ceased to beat. This part—theultimum moriens—is situated in most hearts somewhat loAver than thesinoauricular node. That it is the last part of the heart to cease con-tracting does not necessarily mean that it is the part of the heart inAvhich the be
Physiology and biochemistry in modern medicine . ere this takes place. If the heart isexcised, hoAvever, it will continue to beat for a feAv moments, and as itdies it will be observed that the poAver of contraction remains in the au-ricular region, and particularly at the bases of the vena? cava?, for a con-siderable time after the ventricles have ceased to beat. This part—theultimum moriens—is situated in most hearts somewhat loAver than thesinoauricular node. That it is the last part of the heart to cease con-tracting does not necessarily mean that it is the part of the heart inAvhich the beat ordinarily originates; it means simply that this is thepart of the auricle in Avhich the poAver of contraction remains for the 186 THE CIRCULATION OF THE BLOOD longest time after death. Although the observation does not enable usto determine exactly where the heartbeat originates, yet it makes itvery probable that this is somewhere in the auricles; a conclusion whichis borne out by many other pieces of evidence, such as those obtained by. Fig. 52.—Diagram of an auricle showing the arrangement of the muscle bands; the concen-tration point (); and the outline of the node (). The diagram is to scale, andillustrates by the circles and connecting dotted lines the method of leading off by paired contactsand the subsequent orientation. (From Thomas Lewis.) i Auricular appendage--5/noaurfcu/ar node
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Keywords: ., bookcentury1900, bookdecade1910, bookpubli, booksubjectphysiology
