The theory and practice of medicine / by Frederick T. Roberts.

  • Frederick Thomas Roberts
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: The theory and practice of medicine / by Frederick T. Roberts. Source: Wellcome Collection.

    27/1226 (page 5)
    intelligent comprehension of the mode or modes in which they produce their injurious effects. This may be ohvious enough, but not uncom- monly it is a matter of doubt, or a question involving much controversy. General .Etiological Summary.—The remainder of this chapter is devoted to a general outline of the principal recognized causes of disease but for much necessary detail the reader is referred to special works on the subject. The serological facts relating to individual diseases and symptoms will be subsequently dealt with in their appropriate con- nections. Numerous terms have been employed for the purposes of classifying causes, but they are often very ambiguous, and are of little, if any^ practical value. 1 will, therefore, only allude here to the division into predisposing and exciting causes, the latter under certain circumstances being also named determining. Predisposing causes include those influences which bring about a con- dition of the system as a whole, or of some organ or part, rendering it more liable to become the seat of disease generally, or of some particular lesion. Exciting causes comprehend the immediate and direct agencies by which the different morbid changes are produced. The terra predis- position is used to express the state favourable to the action of an exciting cause, and the individual in whom it exists is said to be predisposed It is not to be supposed, however, that there is any distinct line of demar- cat.on between the two classes of causes thus named; what may only predispose at one time may excite at another, and especially is this true when several influences act together and for a long period Further a so-ca led predisposing cause may only render one organ more liable to be attacked with a certain disease than another; for example, age exercises a marked influence as regards the seat of tubercle or cancer. Jjop the purpose of summarizing the more common causes of disease it WM be convenient to divide them primarily into Intrinsic, or those hE£d*FT* individual, in whom they are either inherent or nfl 2L \ 7R1NSIC;v°* tb°Se ^ t0 accidental> ^d chiefly external ill I 1f8 tHlS \*. Pract,cab]e, an endeavour will be made in pwtrj SS5 WhiCh ™* be ™™ as predisposing, °Pe« Ttjjzz*; IKS comht.ons tend to affect different organs at different age or even o be United to special tissues in a particular organ. This mav often be It f I frtam organs, being much greater at one time of life than at nnf,; mar:fd Ch«iges of structure also, in the direction of decav not 7ZVm \h° *»• to as, for eSpTe II,; , , ' .7f's In advanced life rendering them brittle, and - ^ childreD and ^ p-ns •fa wTwhSj^SS P,°ne t0 Cerfcfti,a,Tection8 than males, and «ex. This (h-r e ids or T T'' liml4ed to one or other in the r C '1'^rence ,n the conditions of special organs