SOFTENING and INDURATION (Ra mollissement et Induration,— Endurcisseinent, Fr., die Erweichung und Ildrtung, Germ.) are terms used to express a pathological or phy siological diminution and increase, of the con sistence of the body or its parts.
Softening and induration in a physiological sense, refer to those changes which occur in the density of tissues and organs during their development, growth, and decay ; whilst, in a pathological sense, they refer to alterations in the normal consistence, with or without actual molecular change.
In order to be able to distinguish morbid alterations of cohesion, from those which oc cur in the natural course of things, it is neces sary to be well acquainted with the power exercised by age, sex, and idiosyncrasy, in modifying the density of the tissues.
Softening and induration are but relative terins, the standard of consistence is con stantly varying, both as regards the whole body, or as regards organs and tissues. In the fcetal state all the tissues are soft, and contain large quantities of fluid ; as develop ment proceeds, so do the parts gradually be come hard, not all equally so, for certain tissues remain permanently soft in comparison to others, which rapidly increase in density. After birth, the hardening processes still con tinue, and it is not until the age of puberty is passed, that all the tissues have attained their highest stage of development. But the pro cess of natural hardening is interfered with, or retarded, by peculiar idiosyncrasy and by the influence of sex and occupation • the general firmness of' the tissue of an athlete is greater than that of those, who, although in perfect health, happen to lead inactive and sedentary lives ; it is greater as a general rule in the male than in the female sex, and in the sanguineous than in the lymphatic temper ament.
As old age comes on, changes in the con sistence of the tissues occur, which are pro duced by the natural decay to which all organized matter is subject ; thus the cellular tissue, the serous and mucous membranes, the niuscles and tendons, bone, the brain and nervous system, and particularly the uterus and ovaries, sometimes acquire a de gree of hardness, equal to that which is known to be produced by certain diseases.
Finally, after death the whole organistn is affected by forces, which had little or no in fluence upon it during life ; the tissues are subjected to the macerating influence of their fluids, which may also act chemically upon them. In the natural course of things, soften
in.- and putreffiction, and disorganization of the ultimate atoms of our body occur, before they are fitted to be assimilated into other organized structures ; this decay increases as time progresses, and is enhanced by a high state of tetnperature and exposure to the air. After death, hypostatic congestion of the cel lular tissue simulates the appearance that this structure frequently presents, when af fected with inflammatory softening ; and the macerating effects of the fluids, which had no such influence during life, are seen in the brain and spinal cord ; whilst the alimentary mucous membrane suffers softening and dis integration from the peculiarities of the fluid usually secreted by it. By recognising then the normal alterations of cohesion, and those arising from post mortem causes, the attributes of morbid softenings will become perfectly apparent.
Softening and induration are said to exist without any structural change ; such is not generally the case, indeed it is exceptional, and were such a state only to be properly termed softening and induration, many of' the most important and interesting pathological facts would be unaccounted for. Softening and induration are produced by a variety of causes, and frequently co-exist in the same organ, or one may supervene on, or cause, the other.
Both softening and induration may be pro duced by inflammation leading, on the one hand, to effusion of serum and pus, and on the other to the deposition and subsequent contraction and hardening of coagulable lymph ; the one appears to be the result of acute, and the other of subacute, inflam matory action. Active sanguineous conges tion produces in some organs the sensation of diminished consistence, whilst in others, especially in those surrounded by a dense fibrous tissue as the testicle, hardening results. In softening, the effused product of inflamma tion, appears not only to break down the structure by infiltration, but also by its pres sure to impede the usual nutrition of the part.