Lectures on inflammation, (delivered in the theatre of the Royal College of Surgeons of England) / by James Paget.

  • James Paget
Date:
1850
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Licence: Public Domain Mark

Credit: Lectures on inflammation, (delivered in the theatre of the Royal College of Surgeons of England) / by James Paget. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    often impossible, and sometimes untrue, and in Btudy, the terms are convenient for the sake of brevity rather than of clearness, Evading, then, the question of the pre- cise definition of inflammation, I shall en- deavour, fii'st, to describe the state of an inflamed part, giving to the description Buch a plan and direction as may best help the chief design of contrasting the inflam- matory, -with the normal, method of nutri- tion, and of showing that the immediate causes, and the chief constituents, of the inflammatory state are to be found in al- terations of those thmgs which are ne- cessary conditions of the healthy nutrition of a part. The conditions of the healthy mainte- nance of any part by nutrition, are—1st, a regular and not far distant supply of blood; 2d, a right state and composition of that blood; 3d (at least in most cases), a certain influence of tlie nervous force; and 4th, a normal state of the part in which nutrition is to be eSected.* All these are usually altered in inflammation. I. The supply of blood to an inflamed part is altered both by the changes of the blood-vessels, especially by their enlarge- ment, and by the mode in which the blood moves throiigh them. The enlargement of the blood-vessels is, I suppose, a constant phenomenon in the inflammation of a part; for, althougli in certain parts, as the comea, the vitreous humour,t and the articular cartilages, some of the signs or effects of inflammation may be found where there are naturally no blood-vessels, yet I doubt whether these ever occur without enlargement of the vessels of the adjacent parts, and especially of those vessels fi-om which the diseased structure derives its natiu-al suj)ply of nu- tritive material, and which may therefore be regarded as being its blood-vessels, not less than those of the part in which they lie. Thus, in inflammation of the cornea, the vessels of the sclerotica and conjunctiva are enlarged, and in idceration of articular cartilages, those of the svu-rounding syno- vial membrane or subjacent bone. The enlargement usually aflects alike the arteries, the capillaries, and the veins of the inflamed part; and usually extends to some distance beyond the chief seat or focus of the inflammation. To it we may ascribe the most constant visible sign of in- flammation,—the redness, asweU as much of the swelling. Its amount is various; it may be hardly percej)tible, or it may in- crease the vessels to twice or three times * See Lectures on Nutrition, &c., in the Medical Gazktte, 1847. t See, especially, a case by Mr. Bowman, in his Lectures on tlie Eye, p. 124. their natural diameter. Extreme enlarge- ment is admirably shown in Hunter's spe- cimen* of the two ears of a rabbit, of which one was inflamed by thawing it after it had been frozen. The rabbit was killed when the ear was in the height of inflam- mation, and, the head being injected, the two ears were removed and di'ied. A comparison of the ears, or of tlie drawings from them, shows all the arteries of the in- flamed ear three or four times larger than those of the healthy one, and many arteries that in the healthy state are not visible, are, in the inflamed state, brouglit clearly into view by being filled with blood. I have repeatedly seen sunilar enlarge- ments of botli arteries, and vems, and ca- pillaries in the stimulated wings and ears of bats. The like phenomena occur in the webs of frogs, and other cold-blooded ani- mals ; but in these, I think, the amount of enlargement is generally less.f The redness of an inflamed part always appears more than is proportionate to the enlargement of its blood-vessels ; cliiefly, because the red corpuscles are much more closely crowded than they naturally are in the blood-vessels. The vessels of an in- flamed part are not only dilated, but appear crammed with the red corpuscles, which often lie or move almost as if no flmd inter- vened between them: then- quantity ap])ear3 increased in far greater proportion than that of the liqixid part of the blood. Tliis pecuharity is even more manifest in the frog than in the bat; for in the for- mer, the crowding of corpuscles may occur in vessels that appear to have undergone no change of size on the apphcation of the sti- mulus. J Another, but a minor, cause of the m- creased redness of the inflamed part is sometimes to be observed in the oozing of the colom-iug matter of the blood-cor- puscles, both mto all tlie intei-spaces be- tween them, and tlu-ough the walls of the small vessels mto the adjacent tissue.. Dm-mg life this may be noticed, especially * Pathological Museum of the College, No. 71. Catalogue, vol. i. p. 33. See also Hunters Works, Vol. ill. p. 322, and PI. xx. t Ennnert, wlio is among the few that nave measured it, says it is equal to one-half or one- third of the normal diameter of the vessels. Bidder denies it altogether. See Henle s and Pfeufer's Zeitschrift, B. ii. and iv. . ± I do not more particularly refer to what is described as the encroachment of the red blood- corpuscles on the lymph-spaces, or the layer ot fluid that lies in .ipparcnt rest adhering to tne walls of the vessels. The too-pointed description of this layer has led to very exaggerated notions concerning it: its existence is certain, but it is too thin for any blood-corpuscle to be at rest in ; and when white corpuscles remain by the walls ofthe vessels, it is evident that they do so more because of their own adhesiveness than because a small portion of the fluid about them is at rest.