Introduction To Pathology PDF

INTRODUCTION TO PATHOLOGY  The core aspects of diseases in pathology Pathology is the study of disease by scientific methods. The word pathology came from the Latin words “patho” & “logy”. ‘Patho’ means disease and ‘logy’ means study, therefore pathology is a scientific study of d...

INTRODUCTION TO PATHOLOGY  The core aspects of diseases in pathology Pathology is the study of disease by scientific methods. The word pathology came from the Latin words “patho” & “logy”. ‘Patho’ means disease and ‘logy’ means study, therefore pathology is a scientific study of disease. Diseases may, in turn, be defined as an abnormal variation in structure or function of any part of the body. Pathology gives explanations of a disease by studying the following four aspects of the disease. 1. Etiology, 2. Pathogenesis, 3. Morphologic changes and 4. Functional derangements and clinical significance.  Etiology Etiology of a disease means the cause of the disease. If the cause of a disease is known it is called primary etiology. If the cause of the disease is unknown it is called idiopathic.  Pathogenesis Pathogenesis means the mechanism through which the cause operates to produce the pathological and clinical manifestations. The pathogenetic mechanisms could take place in the latent or incubation period. Pathogenesis leads to morphologic changes  Morphologic changes The morphologic changes refer to the structural alterations in cells or tissues that occur following the pathogenetic mechanisms. The structural changes in the organ can be seen with the naked eye or they may only be seen under the microscope. Those changes that can be seen with the naked eye are called gross morphologic changes & those that are seen under the microscope are called microscopic changes. Both the gross & the microscopic morphologic changes may only be seen in that disease, i.e. they may be specific to that disease. Therefore, such morphologic changes can be used by the pathologist to identify (i.e. to diagnose) the disease. In addition, the morphologic changes will lead to functional alteration & to the clinical signs & symptoms of the disease. Functional derangements and clinical significance The morphologic changes in the organ influence the normal function of the organ. By doing so, they determine the clinical features (symptoms and signs), course, and prognosis of the disease.  Diagnostic techniques used in pathology The pathologist uses the following techniques to the diagnose diseases: a. Histopathology b. Cytopathology c. Hematopathology d. Immunohistochemistry e. Microbiological examination f. Biochemical examination g. Cytogenetics h. Molecular techniques i. Autopsy