Copy 1, Volume 1

The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good].

  • Good, John Mason, 1764-1827
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good]. Source: Wellcome Collection.

    63/784 (page 9)
    thousand experiments, and which completely decides the question, that vomiting may be produced by the action of the stomach itself, unassisted by any external compressing force.” On the whole, however, from the various facts which have been made out on the present topic, and to some of which we shall advert in the chapter on Limosis Emesis, it may be inferred, that, in ordinary vomiting, the contraction of the stomach itself is not essential, any more than the compression of the diaphragm and abdominal muscles under extraordinary circumstances. Nothing can be more aptly contrived for the purpose of agitating, mixing, and presenting every portion of the alimentary mass to the surface, by which certain parts are to be absorbed, than is the whole structure of the-small intestines. While its muscular fibres are calculated to produce a constant undulatory vermicular motion, these are loosely lined by the absorbing membrane, whose numerous plicee and valves form a most extensive surface, with their villi erected, and even mixed, as it were, with the semifluid alimentary matter. Then the outside of these bowels consists of a smooth and constantly lubricated surface, greatly facilitating the motion of the different convolutions upon each other.* ] In the more perfect classes of animals, the division between the Small in- testines. Valve of valve, formed jointly of the coats of the colon and the ileum by a short natural introsusception of the terminating portion of the latter into the commencing portion of the former; the important use of which is to moderate the flow of the contents of the smaller intes- tines into the latter, and to prohibit a regurgitation of feces into the former. And hence we never meet with fecal matter in the stomach, except in cases in which this valve or sphincter has lost the whole or a considerable portion of its muscular power. In the hedgehog, and several other quadrupeds, the valve of the colon does not exist ; and in a few others, as the sloth and armadillo, the ccecum is want- ing. In birds, the rectum, at the termination of its canal, forms an oval or elongated pouch, called bursa Fabriei, from the name of its discoverer; and then expands into a cavity, which has been named cloaca, from its receiving the extremities of the ureters and genital organs and their secretions; so that the fluids from all these are discharged from one commonemunctory. The same mechanism is extended to a few quadrupeds, as the ornithorhynchus paradoxus, and the hystrix: the penis of the male, and the horns of the uterus in the female being equally lodged in its interior. + Contributory to the function of digestion, performed in the stom- ach and the parts of the alimentary canal immediately adjoining to it, are several organs which lie near it, and are connected with it in a peculiar manner. Of these the chief are the pancreas, the liver, the spleen, and the omentum. ‘The two last are less constantly found in the animal kingdom than the liver, to which they are by many physiologists supposed to be subservient. They generally become more obscure or diminish in size from quadrupeds to-fishes: a remark that will equally apply to the pancreas, which upon the whole disappears sooner than the spleen. It is found in the shark * See Bright’s Gulstonian Lectures, in Medical Gazette, for June 1833, p. 282. + Sir E. Home; in Phil. Trans., 1802, pts 1. and 2. Cloaca, Collatitious organs of digestion.