Contributions to the physiology of the alimentary canal / by William Brinton.

  • Brinton, William, 1823-1867.
Date:
[1849]
Catalogue details

Licence: Public Domain Mark

Credit: Contributions to the physiology of the alimentary canal / by William Brinton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Prior to any experiment, a consideration of the mechanism of such an organ leads to the same conclusions. The simplest form to which we could reduce it would be that of an inflexible hollow cylinder, in which the transverse indenta- tion might be represented by a circular septum, perforated at its centre, and capable of free movement on the interior surface of the tube which it accurately fits. Let such a septum be moved in either direction, and it at once exerts a pressure on the body of liquid contained in the end towards which its motion sets. The pressure being equal in all directions, a portion of the fluid escapes backwards through its aperture, and this retrograde course is, pro tanto, a current, and one which will be continually lengthened by the advance of the septum along the remainder of the tube. The successive movement of a series of such septa would result in the establishment of two currents in the liquid —a peripheric of advance, and a centric of return. The membranous and distensible nature of the tube actually made use of complicates the result only thus far: that at the commencement of the contractions, some distension of the distal extremity occurs. The inconsistencies before alluded to, might therefore pro- bably receive the following explanation : Transverse contractions, of uniform direction, occurring in a closed tube filled with a liquid, and falling short of obliterating its calibre, necessarily imply two currents—a superficial or peripheric, in the direction of those contractions, and an axial or centric, having precisely the reverse course. The conditions here specified evidently exist in the case of simple tubular stomachs; nor does the modification of shape which is at present in the human and similar stomachs, affect their existence, since, so far as I have seen, the movements both in the cardiac pouch, and the more vigorously-contracted pyloric extremity, are transverse to the axis of the organ, as defined by its cavity and apertures. And applying the same theory as before, it seems highly pro- bable that we have at once a complete elucidation of the revolu- tions of the food, which Dr. Beaumont witnessed, and a corro- boration of the general accuracy of his observations. The return of the alimentary bolus, was, to all appearance, along the essei curvature ; and when we recollect the situation of the opening into the viscus, from which his observations were made, it is evident that a movement along the real axis of the organ would be so near to the curved border, and comparatively so far rom the point of view, that he could scarcely have avoided imputing to it the course which he has done.