General pathology is the foundation of pathology that studies the mechanisms of disease including etiology, pathogenesis, and common changes in tissues. It covers topics such as cell injury and adaptations, tissue injury, healing, hemodynamic diseases, neoplasia, and infectious and parasitic diseases. The objective of pathology is to identify and describe the different parts of the disease process by studying the etiology, pathogenesis, morphological changes, and functional derangements of diseases.

1. MID 2163 PATHOLOGY

2. DIVISIONS OF PATHOLOGY GENERAL PATHOLOGY SYSTEMIC PATHOLOGY CLINICAL PATHOLOGY ANATOMIC PATHOLOGY SURGICAL PATHOLOGY PATHOPHYSIOLOGY

3. General Pathology Also called investigative pathology experimental pathology theoretical pathology

4. General Pathology Foundation of pathology Study of the mechanisms of disease – etiology & pathogenesis The common changes in all tissues

5. 1. INTRODUCTION TO PATHOLOGY 2. CELL INJURY & ADAPTATIONS 3. TISSUE INJURY 4. HEALING 5. HAEMODYNAMIC DISEASES 6. NEOPLASIA 7. INFECTIOUS & PARASITIC DISEASES

6. INTRODUCTION TO PATHOLOGY

7. What is?? -PATHOLOGY- “ study of disease by scientific method” pathos : suffering or disease ~logos : study of

8. Objective of Pathology To identify and describe the different parts of a disease process

9. Disease??? Abnormal variation in structure or function of any part of body

10. Pathology... Explain the disease by studying the 4 aspects of the disease: Etiology Pathogenesis Morphological changes Functional derangement & clinical significance

11. Etiology aitia : cause ~logos : study “ study of causation or origin of disease”

12. Etiology Why things occur? Factors that produce/predispose toward a certain disease or disorder Cause of disease primary etiology: known idiopathic: unknown Help in diagnosis, understanding and treatment of disease

13. Etiology 2 major etiological factors Genetic: age, genes Acquired: infectious, environmental, nutritional etc Etiology is followed by pathogenesis

14. Pathogenesis pathos : disease genesis : creation “ mechanism / development of disease”

15. Pathogenesis Process of disease Starting from the initial stimulus to the ultimate expression of disease the origin & development of disease: acute, chronic, recurrent Gross & microscopic structure, function, chemistry and molecular mechanism

16. Pathogenesis Types of pathogenesis include Microbial infection, inflammation, malignancy & tissue breakdown Most disease caused by multiple pathogenetical process together Example: cancer – multiple pathogenesis Pathogensis leads to morphological changes

17. Morphological Changes “ structural alterations”

18. Morphological Changes Structural alterations in cells or tissue that occur following the pathologenetic mechanisms the characteristic of disease or condition changes maybe specific to a disease thus, it help the pathologist to identify & diagnose the disease

19. Morphological Changes The changes can be seen with Naked eye – gross morphologic changes Under microscope – microscopic changes Morphological changes will lead to functional alteration and the clinical signs & symptoms of disease

20. Functional Derangement & Clinical Significance

21. Functional Derangements Disturbance of normal function of the organ due to the morphological changes Determine the clinical features, course and prognosis of a disease

22. Clinical Significance Clinical manifestations Signs Symptoms Prognosis

23. Signs Objective indication of some medical fact or characteristic the characteristic of disease or condition changes maybe specific to a disease thus, it help the pathologist to identify & diagnose the disease

24. Symptoms Subjective – e.g: stomachache, lower back pain, fatigue = can be sensed by the patient 3 main types of symptoms Chronic : long lasting/recurrent Relapsing : affected by symptoms again Remitting : symptoms improve & sometimes fade away completely

25. Symptoms Asymptomatic – NO symptom Asymptomatic disease condition Disease present but there ar no symptom e.g: Ca Breast Asymptomatic infection Infected person may transmit the diasease to others Cause complication that unrelatede to the infection e.g: STD – AIDS, genital warts

26. Prognosis Medical term to describe the likely outcome of an illness Complete prognosis include expected time, function and description of disease course Help to determine to attempt certain treatments or withold Certain test for prognostic indicator Estimators to describe prognoses = progression-free survival , survival rate & survival time

27. Causes of Disease Can be caused by environmental factors, genetic factors or combination of the two

28. Environmental Factors Physical agents Chemicals Nutritional dificiencies & excesses Infections and infestations Immunological factors Psycogenic factors

29. Environmental Factors Physical agents Apply excess energy in any form to the body e.g: trauma, radiation, extreme temperature, electric power Chemicals Chemical agents = chemically induced injury Effects = toxic to all cell (cyanide), act locally at site of application (strong acids), toxic to certain organ esp liver & kidney

30. Environmental Factors Nutritional dificiencies & excesses Dificiencies poor supply, interference of absorption, inefficient transport within the body or defective utilization – major class of food or essential elements Excess - obese

31. Environmental Factors Infections and infestations Infected by viruses, bacteria, fungi, protozoa, metazoa Cell destruction directly when infection happen – virus & protozoa Destruction from toxins by the infecting agent – diphteria, tetanus General or localize effects

32. Environmental Factors Immunological factors Abnormal immune system Hypersensitivity reaction : exaggerated immune response to an antigen – bronchial asthma Immunodificiency : increase susceptibility to different diseases – AIDS Autoimmunity : abnormal (exaggerated) immune reaction against self antigens - SLE

33. Environmental Factors Psycogenic factors Mental stress imposed by condition of life Maybe contributory factors in some group of diseases

34. Genetic Factors Hereditary factors that are inherited genetically from parents Mutation in chromosomes

35. Course of Disease “ the series of events in a disease incident in a patient” The natural history of the disease (if no intervention from other factors)

36. EXPOSURE BIOLOGICAL ONSET CLINICAL ONSET PERMANENT DAMAGE DEATH

37. Exposure Exposure to various risk The causative agents Latency period Period between exposure and biological onset of disease Biological onset Marks the initiation of disease process NO sign or symptom May remain asymptomatic or subclinical (no clinical manifestations) or may lead to overt clinical diasease

38. Incubation period Variable period of time without any obvious signs or symptoms from the time of exposure Clinical onset of disease Signs and symptoms become apparent Expression of disease may be variable in severity or in range of manifestations Onset of permanent damage Death Clinical death Biological death

39. Clinical Death Occurs when heart stop beating – cardiac arrest Reversible transmission between life and biological death Definition: period of respiratory, circulatory and brain arrest during which initiation of resuscitation can lead to recovery

40. Clinical Death Signs No pulse or blood pressure = completely unresponsive to the most painful stimulus Pupils widely dilated Recovery can occur with resuscitation

41. Biological Death Sure sign of death Sets in after clinical death Irreversible state of cellular destruction Manifest with irreversible cessation of circulatory and respiratory functions all functions of the entire brain including brainstem