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.

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    often impossible, and sometimes untrue, and in study, 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, first, to describe the state of an inflamed part, giving to the description such 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 things 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 5 3d (at least in most cases), a certain influence of the nervous force; and 4th, a normal state of the part in which nutrition is to be effected.* All these are usually altered in iiffLammation. * 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 through them. The enlargement of the blood-vessels is, I suppose, a constant phenomenon in the inflammation of a part; for, although in certain parts, as the cornea, the vitreous humour,f 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 from wrhich the diseased structure derives its natural supply 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 ulceration of articular cartilages, those of the surrounding syno¬ vial membrane or subjacent bone. The enlargement usually affects 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, as well as much of the swelling. Its amount is various; it may be hardly perceptible, or it may in¬ crease the vessels to twice or three times * See Lectures on Nutrition, &c., in the Medical Gazette, 1847. f See, especially, a case by Mr. Bowman, in his “ Lectures on the 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 dried.” A comparison of the ears, or of the drawings from them, showTs 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, brought clearly into view by being filled with blood. I have repeatedly seen similar enlarge¬ ments of both arteries, and veins, 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 ; chiefly, 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 ahnost as if no fluid inter¬ vened between them: then* quantity appears increased in far greater proportion than that of the liquid part of the blood. This peculiarity 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 application of the sti¬ mulus.;!: Another, but a minor, cause of the in¬ creased redness of the inflamed part is sometimes to be observed in the oozing of the colouring matter of the blood-cor¬ puscles, both into all the interspaces be¬ tween them, and through the walls of the small vessels into the adjacent tissue. During life this may be noticed, especially * Pathological Museum of the College, No. 71. Catalogue, vol. i. p. 33. See also Hunter’s Works, Vol. iii. p. 322, and PI. xx. t Emmert, who is among the few that have 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 lympli-spaces, or the layer of fluid that lies in apparent rest adhering to the 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 lie at rest in ; and when white corpuscles remain by the walls of the 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