The contents of pathology Aetiology ( the causes ) Pathogenesis ( mechanisms ) pathologic changes : structural &

1. The contents of pathology • Aetiology(the causes ) • Pathogenesis (mechanisms) • pathologic changes: structural & functional abnormalities • the descriptions of the manifestations • its progress and sequelae.

2. Causes of disease Identification of the causative factors that initiate the disease process. 1). Genetic factors 2). Environmental factors Although the causes of disease are divided into above two main groups, but both groups are interlaced in most diseases.

3. 2. Pathogenesis • Defining the disease mechanisms. How do the causative factors change normal physiological processes? How do these functional changes cause changes in tissue structure? Most are still investigating. Some of them should be known, for instance: • Thrombosis • Myocardial infarction

4. 3. Pathologic changes What are the specific changes in function and structure that characterize each disease? Level A.Naked eye level: gross changes in diseased organs. Level B.Light microscopic level: in histological and cytological level. Level C.Electron-microscopic(EM) level: in the ultrastructure (cellular organelles). Level D.Molecular level: inspect aberrant in DNA, RNA, and protein.

5. 4. Manifestations The functional consequences of the morphologic changes. Can these changes from normal be detected by clinical tests such as examination of the blood or urine? Can the structural changes be identified by techniques such as x-ray, ultrasound, nuclear medicine, or examination of tissue samples (biopsies)? What clinical signs and symptoms are produced by the disease process? How does the disease process produce these signs and symptoms?

6. 5. Progress and sequels • Progress simple intricate short-term long-term • Sequels healing un-healing: delay & complications spread even death

7. TASKS OF A PATHOLOGIST In medical practice, the objective of the study of disease has several purposes: • Diagnosis: to determine the nature of the disease process and its causation, i.e. to establish a diagnosis if possible. • Treatment: To monitor the extent and progress of the disease and provide an indication of prognosis. Treatment of the patient's disease is very often based on this information. • Prevention: To use knowledge of the mechanisms of disease to prevent disease in individuals or populations of people or animals.

8. The classification of pathology • General pathology: A discussion of disease fundamentals oriented horizontally (nature of process). injury, repair, inflammation, neoplasia. • Systemic pathology: A more detailed discussion of diseases oriented vertically. i. e. cardiovascular diseases, respiratory diseases, alimentary diseases, endocrine diseases, renal diseases, infectious diseases. e.g. What is the commonest disease in the clinic: trachoma, common cold, gastritis, hepatitis,athlete's foot

9. The location and importance of pathology in medical education Pathology is a bridge between basic science and clinical medicine. All of the medical students have to stride over the bridge!