Page:The New International Encyclopædia 1st ed. v. 10.djvu/700

* INFLAMMATION. 614 INFLAMMATION. and nervous systems, to whic-h various names, such lis (.'oustitutioual disturbance, symptcjuiiitiv or inlliinuiiatury fever, pyrexia, etc., Iiiivc beeu applied. It' the foreign hody is extnuted. the prohiibility is thnt all these syiiiptnins will f.'riulu- ully abate, until the part at len;L:th regains its natural appearance and sensations. It, linwever, the cause of irritation is not removed, or if the intensity of the morbid process exceed a certain point, the followiii;,' phenomena cKcur: The swell- ing assumes a more pnijcctinji; or pointed fonn, the part becomes softer, and the skin at ils centre, which is usually the most ]irojectinj,' part, becomes whiter. There is a sensation of throb- bing pain, and if the skin be not divided with a knife it linally breaks, and a yellow, oream-Iike lluid, known as pus (q.v. ), escapes, after which the symptoms rapidly abate. This process is known as Kuppiirdlion. ■ If the oritdnal injury was very .severe and the inllanunation intense, there may be actual ileath of the part all'ccted. In that case, the red cohir of the skin becomes p ple or f;reenishblack, the pain ceases, and the part becomes dead and putrid. This is morli/iciilion. I'nder favorable circumstances this dead part, which is called a slouiih, spontaneously separates from the adj.a- cent livinj; parts by a process known as ulcera- tion, and the cavity which is thus formed grad- ually tills up and heals. ' The pain may vary from mere discomfort to intense agony. There is usually most |)ain in those parts in which the tensicm produced by the swelling is the greatest, as under the periosteum, or beneath serous or fibrous membranes, etc. The pain occurring in inllammation is always aggravated by pressure, and by this means the physician can often distinguish between inllam- matory and non-inllammatory disorders. The heat is seldom so much increased as the sensa- tions of the patient would lead him to believe; it does not rise above the ma.ximum heat of the blood in the interior of the body. This inere.ise of heat depemls upon the increased How of ar- terial (or highly oxidized I blood to the part. The redness depends upon there being more blood than usual in the vessels of the atTei'ted part. The xicrlliiiii depends in part upon the distention of the blood-vessf Is and upon the pres<'nce of various lluids. such as blood-serum and pns, in the tissue of the alfected part. For the study of the details of the inflamma- tory process and of the sequence of the changes which take place, it is most satisfactory to ob- serve their progress in living tissues. If the inesenterj' of a frog whose nuiseiilar system has Iwen paralyzed by curare be exposed to the air, this unaccustomed exposure starts inflammatory changes which can be observcil under the micro- scope. There is first seen to he an increase in the rate of Idond-flow through the capillaries; then the capillaries become somewhat dilated, and the blood-current becomes slower than nor- mal. White blooilcclls accumulate aloiisj the capillary walls, and at various points stop and attach themselves to the endothelial cells. If these white Idooil-cells he watched carefullv. some of them may he seen to pass throuch the cement substance hetween the endothelial cells, and in this way pass out into the surrounding tissues. Pome fluid is al«o seen to .Tccumnlate in the tissues, this fluid havintr evidentlv come from the fluid elements of the Mood. .lso red bloodeells in greater or less numbers may pass, out of the vessels and be found in the surround- ing tissues. These elcitients which leave the vessels and ai-cuniulate in the tissues during the inllammatory pro<ess are called "exudates.' I heir as 'exudation.' and this form of inflanunation is often designated "exudative inllanunation.' The passage of the blootl-corpusclcs out into the tis- sues is called "emigration' or "iliapeilesis." The scrum of exudation contains the librinforming elements of the blood, and so may lead to the formation of more or less tibrin in the tissues. The white blood-cells die and disintegrate (as they are especially prone to do in the presence of certain forms .jf bacteria), and form with the serum the thick, opaque, yellowish lluid that is known as 'pus,* the dead white blood-cells being the pus-cells. .According to the way in which the elements of the exudate are asso<'iated ami their relative proportion, the inllamirialion is known as serous, serofibrinous, seropunilcnt. or purulent. When red cells are jiresent in uiuisual numl)ers, the inllanunation is designated 'hem- orrhagic' inllammation. Such an inllanunation as that described in the frog's mesentery may subside on the removal of the exciting cau.sc. The serum is reabsorbed into the blood-vessel - or Ivmphaties. the living blood cidls find their way ba<lc into the circulation, while those that are di-ad disintegrate and are absorbed. This process is known as 'resolution.' The character of an inllanunation is largely modified by the nature of the tissue in which it occurs. Thus, when an inilanunatiim occurs in dense fibrous tis sue there is little chance for much distention, ami the amount of exudate is .limited bv pressure. In tissues of looser texture the amount of exu- date is apt (o l)e larger. Mucous surfaces such as those lining the gastro-intestinal canal, the respiratory tract, and the genito-urinarv tract react to the infiammatory process by at first a decrea.se in the anmunt of mucus, fullowini; which there is a marked increa.se of mucous se cretion. This being in many ea.ses the dominant feature, the inllammation is designated 'mucous' or 'catarrhal' indummation. t)n serous surface^ such as the pleura, peritoneum, and pericardium the seio-fihrinous exudate often leads to an ag glutiiiatiou of the opposing surfaces nn<l the formation of adhcsinns. These adhesions bind the surfaces together and materially interfere with the natural free motion of the parts. Such a condition obtains in the so-called 'fibrinous' form of pleurisv. It is very common after in- flammations of the pelvic organs in the female and after appendicitis. These adhesions ma.v become organized by the development of blood- vessels in them, and so become converted into actual living tissue. In abilominal operations, extensive adhesions resulting from pn^sent or previous inflammatory processes and i)inding to- gether the different viscera often offer the most diflicult problem with which the surgeon is con- fronted. In inllammation of the iris the pupil ma.v he rendered irregular or immovable, or mav he even closed up by the formation of adhesions. In endocarditis, or inflammation of the mem- hrane lining the heart, fibrin may tie deposited in wartlike masses upon the valves, thus inter- fering with their functions and causing some of the worst forms of cardiac disease. See TTkmit. Diseases ok.
 * )ussage from the vessels into the tissues is known