The laws and mechanics of circulation, with the principle involved in animal movement . elated with the spinal nerves tothe external parts, concert of action is readily produced, sothat the whole performs as but a single organ only for pump-ing aii* and blood through the alveoli for respiratory in the later stages in development, when a diaphragmcomes into the scheme for separating the viscera in the abdo-men from the viscera in the chest, likewise the phrenic nerves(Fig. 91, F) for coordinating this portion with the externalparts, so that the utmost harmony is produced throughout
The laws and mechanics of circulation, with the principle involved in animal movement . elated with the spinal nerves tothe external parts, concert of action is readily produced, sothat the whole performs as but a single organ only for pump-ing aii* and blood through the alveoli for respiratory in the later stages in development, when a diaphragmcomes into the scheme for separating the viscera in the abdo-men from the viscera in the chest, likewise the phrenic nerves(Fig. 91, F) for coordinating this portion with the externalparts, so that the utmost harmony is produced throughout, * For the purpose of illustration simply being fundamentally the same as inthe frog. MODE OF COORDINATING THE LUNGS AND BODY-WALLS 67 the correlation of all these nerves in the medulla oblongataenabling this to be very readily done. There is increasingcomplexity, but the principle in the mechanics furnishes akey for easily unraveling the structures, which are meansto ends simply. The existence of the pneumogastric nerves,then, is readily accounted for. The role they perform in the. Fig. 31.—Left Pneumogastric Nerve, in diagram (Dalian). 1, pharyngeal branch ;2, superior laryngeal; 3, inferior or recurrent laryngeal nerve ; 4, pulmonarybranches ; 5, 6, stomach, liver, etc. viscera in the abdomen will come up later, but its importancewould be difficult to overestimate. In the fishes we havethe analogue of this in the opercula and branchia, togetherwith the branches of the 8th pair (Fig. 166) for setting up thepumping actions for producing afflux and efflux of the water 08 PORTAL CIRCULATION INCREASED BY RESPIRATION. and blood in these organs ior r ? spiratory purposes, while theother portions are continued on into the abdomen and theexternal muscular walls (Fig. 15S, o, 4) for coordinating themwith the branchia and opercula, or the same as in the air-breather, the principle being the same. And so likewisedown the whole chain in development to where a visceralcavity ceases to
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Keywords: ., bookcentury1800, bookde, booksubjectblood, booksubjectrespiration
