1. Introduction to Pathology And its rule in the diagnostic process Dr: Wael H.Mansy, MD Assistant Professor College of Pharmacy King Saud University

2. Definition of pathology It is the “ Scientific study of disease". "scientific study of the molecular, cellular, tissue, or organ system response to injurious agents." Pathology serves as a "bridge" or "link" between the preclinical sciences (anatomy, physiology, ……etc.) and the courses in clinical medicine.

3. What is the Disease? It is the “State in which an individual exhibits an anatomical, physiological, or biochemical deviation from the normal” Disease may be defined as :Disease may be defined as : an abnormal alteration of structure or function in any part of the body.

4. Classification of Diseases:  Developmental – genetic, congenital.  Acquired: *Inflammatory – Trauma, infections, immune, etc. *Neoplastic – tumors cancers *Degenerative – ageing. *Metabolic. *Iatrogenic: Drug induced.

5. In order for a subject or course to be meaningful, one should become familiar with the basic terminology applicable to that subject. Basic Language of Pathology

6. Branches of Pathology General Pathology General Pathology Systemic Pathology Systemic Pathology Gross Pathology Gross Pathology Cellular Pathology Cellular Pathology Surgical Pathology Surgical Pathology Clinical Pathology Clinical Pathology Immunopathology Immunopathology

7. Learning Pathology: General Pathology – Common changes in all tissues. e.g.. Inflammation, cancer, ageing, edema, hemorrhage ….etc. Systemic Pathology – Discussing the pathologic mechanisms in relation to various organ systems e.g. CVS, CNS, GIT…..etc.

8. What should we Know About A Disease Definition. Epidemiology – Where & When. Etiology – What is the cause? Pathogenesis - Evolution of dis. Morphology - Structural Changes Functional consequences Management Prognosis Prevention Pathology

9. Pathology focuses on 4 aspects of disease: ETIOLOGY: Cause of disease. ETIOLOGY: Cause of disease. PATHOGENESIS: PATHOGENESIS: Mechanisms of development of disease. Mechanisms of development of disease. MORPHOLOGY: MORPHOLOGY: The structural alterations induced in cell and tissues. FUNCTIONAL CONSEQUENCES: FUNCTIONAL CONSEQUENCES: Functional results of the morphologic changes, as observed clinically. Functional results of the morphologic changes, as observed clinically.

10. Knowledge of etiology remains the backbone of: Disease diagnosis Understanding the nature of diseases Treatment of diseases. Etiology “Study of the cause of a disease"

11. An etiologic agent : is the factor (bacterium, virus, etc.) responsible for lesions or a disease state. Predisposing Causes of Disease: Factors which make an individual more susceptible to a disease (damp weather, poor ventilation, etc.) Exciting Causes of Disease: Factors which are directly responsible for a disease (hypoxia, chemical agents…. etc.).

12. One etiologic agent several diseases, as smoking.One etiologic agent several diseases, as smoking. Disease Several etiologic agents one disease, as diabetes. Several etiologic agents one disease, as diabetes. Disease One etiologic agent - one disease, as Malaria. One etiologic agent - one disease, as Malaria. Etiology

13. Etiology: What is the cause?  Environmental agents: Physical Chemical Nutritional Infections Immunological Psychological  Genetic Factors: Age Genes : Multifactorial: As Diabetes, Hypertension As Diabetes, Hypertension Cancer Cancer

14. pathogenesis The sequence events in the response of the cells or tissues to the etiologic agent, from the initial stimulus to the ultimate expression of the disease,”from the time it is initiated to its final conclusion in recovery or death” The core of the science of pathology — the study the pathogenesis of the disease.

15. Morphology: Structural Changes Structural changes in disease. Tumor in a cancer. Ulcer in an infection. Atrophy in dementia. Gross & Microscopic.

16. Clinical Symptoms & Signs Clinical signs are seen only in the living individual. “Functional evidence of disease which can be determined objectively or by the observer" (fever, tenderness, increased respiratory rate, etc.)” Clinical symptoms are the patient’s complain usually by its own words. Clinical symptoms are the patient’s complain usually by its own words.

17. Necropsy: Gross examination of the animal cadaver by systematic dissection in order to evaluate any abnormal changes (lesions) that may be present. Autopsy: Synonymous to necropsy in human medicine Biopsy: Removal and examination of tissue obtained from the living body Euthanasia: Intentional putting to death of an individual with an incurable or painful disease by employing humane means

18. prognosis Expected outcome of the disease, It is the clinician's estimate of the severity and possible result of a disease.

19. I hear, I forget I see, I remember I do, I understand Chinese Proverb..