GENERAL PATHOLOGY

GENERAL PATHOLOGY

General pathology is the study of the functional and structural changes that occur in cells and tissues as a result of direct damage by, or reactions to, a wide range of unfavourable circumstances. At any given time our knowledge of these circumscribed by the techniques available to study these processes. Despite this reservation, it is probably true to say that the number of responses of the mammalian cell is finite. These responses represent, on the whole, either an increase or a reduction or loss in some of the components of a large, but not infinite, number of normal cell processes.

            This general principle holds good only so long as so change has taken place in the genome of the target cell or in the transcription of its genetic information. If such changes have occurred, them a new range of phenotypic characteristics and new responses, not characteristics of this cell (at least in its adult or fully differentiated form), may be acquired. The words “adult or fully differentiated” should be stressed because the acquisition of apparently new functions (such as the secretion of fetal antigens by the cells of the tumours) may be the expression of functions that were normal and appropriate at an earlier stage of the organism’s embryological development.