Basic Pathology Introduction PDF

Basic pathology a- Suffering - Study of disease Dr. Mishaal  Introduction  Objectives: The student should: A. Have an idea about Historical background and development of pathology. B. Discuss the impo...

Basic pathology a- Suffering - Study of disease Dr. Mishaal  Introduction  Objectives: The student should: A. Have an idea about Historical background and development of pathology. B. Discuss the important concepts of disease in pathology C. Understand the meaning of the terminology used during the study of a disease like etiology, pathogenesis, morphology, prognosis, etc. D. Understand the role of pathology and its various sub-specialities in the diagnostic process with special emphasis on histopathology and cytology. E. Understand the role of diagnostic pathology in disease management. F. Be aware of some of the principle techniques used in pathology like light microscopy, cytology, immunohistochemistry and molecular pathology, and autopsy.. How paths helps in diagnose ← treat the patient  History Religious beliefs and magic to rational approach (prehistoric time to AD1500) oath Hippocrates Greeks: - Asclepios, Apollo - Socrates, Plato, - Aristotle - Hippocrates Romans: Celsus, Galen Indians: Dhanvantri, Charaka, Sushruta Europe ( Middle ages): Theory of vitalism  History Religious beliefs and magic to rational approach (prehistoric time to AD1500) Islamic civilization era: rational and holistic and experimental approach: - Avicenna Clbnu Sina) - Al-razi - Alzahrawy (The medicine was non-existent and it was found by Hippocrates, dead and made a live by Galen, dispersed and collected by AL-Razi, incomplete and completed by Avicenna.)  History Religious beliefs and magic to rational approach (prehistoric time to AD1500) Islamic civilization era:  History Human Anatomy to Era of Gross Pathology (AD1500-1800) Nb ' Renaissance:i.÷ :* - Leonardo da Vinci (1452-1519) - Vesalius (1514- 1564) - Fallopius (1523- 1562)  History Human Anatomy to Era of Gross Pathology (AD1500-1800) Leeuwenhoek (1632-1723) the microscope Malpighi (1624-1694) Morgagni(1682-1771)clinico-pathological correlate Pott (1714-1788) Hunter (1728- 1793) pathology museums Hodgkin Xavier Bichat, RTH Laennaec Rokitansky cytology  History Human Anatomy to Era of Gross Pathology (AD1500-1800)  History Technology Development & Cellular Pathology (1800-1950) Louis Pasteur microbes Hansen Ehrlich immunology and clinical pathology based cell wall of on Gram bacteria staining bacteria - - Romanowsky Koch May-Grunwald and Giemsa Leishman Feulgen Rudolf Virchow: father of modern pathology  History Technology Development & Cellular Pathology (1800-1950) Pathology- History  Virchow’s Hypothesis Ruldolf Virchow (1821-1902), German pathologist, father of modern pathology has stated the cellular pathology concept; “All diseases are…reducible to disturbances, either active or passive, of large groups of living units whose functional capacity is altered in accordance with the state of their molecular composition and is thus dependent on physical and chemical changes of their contents.” -Virchow, Cellular Pathology, 1855 Implication: diseases can be defined by observing morphologic changes in cells  History Before the year 1800 AC, it was postulated that diseases are spontaneously generated, independent of any external causes or other influences. This attitude seems unreasonable to us today, but at that time nothing was known of infectious agents (such as bacteria and viruses, etc.) or cancer causative agents (such as ionizing radiation and carcinogenic chemicals, etc.). Pathology, and consequently medicine, has been revolutionized by the application of microscopy to the study of diseased tissues from about the year 1800 AC. The primitive light microscope of Rudolf Virchow (1821- 1902), enabled him to see changes in diseased tissues at a cellular level. His observations have had a profound influence on the understanding of many diseases.  Introduction Cells in normal conditions can alter their functional state in response to modest stress ( changes) and undergo adaptations (physiological) in response to modest stress (changes) to maintain the steady state (homeostasis) In the normal state the body maintains continuous monitoring, adjustments and adaptations (homeostatic mechanisms) to the internal environment (internal milieu) and external environment from the first to the last hours of life to maintain normal physiological state (homeostasis).  Normal homeostasis Normal homeostasis is the steady (stable) state in which cells and tissues found normally. It is achieved by adequate response to internal environment (internal milieu) and external environment changes. This is done mainly by : 1- Genetic programs for: –metabolism –proliferation –differentiation & specialization 2- Constraints of neighbouring cells and matrix play main role  Introduction The failure of these homeostasis maintaining mechanisms and physiological adaptations, it leads to disease (pathology). In more excessive stresses, or adverse stimuli or injurious agents, the cells response to stimuli result in : - Adaptation (pathological adaptation) - Cell injury and degeneration ( reversible or irreversible)  Pathology Pathology definition: is the study of diseases by scientific methods. Pathology is literally the study (logos) of suffering (pathos). The ultimate goal of pathology is the identification of the causes of disease, a fundamental objective that leads the way to disease treatment and prevention. Disease : abnormal variation in structure and/or function of any part of the body.  Pathology In the pathology of any given disease there are structural changes of the relevant tissues that are reflected as functional disturbances, which in turn are perceived as clinical features. The range of the structural changes varies from those affecting sub-cellular organelles (molecular pathology) up to alterations seen by the naked eye (gross pathology). Pathology is a dynamic science in that its contents are continuously subject to changes, revisions and expansions. This is because there are always new findings that shed more light on, add or modify an already established knowledge of various diseases.  pathology Therefore in medicine diseases are studied under the following headings: prognosis → follow of the Definition up patient Epidemiology of disease Etiology (Why?): The cause of a disease Pathogenesis (How?) : The mechanism producing a disease Morphology ( Pathomorphology)(Morbid anatomy) (What?) : Structural changes due to disease, it is divided into Gross/ macroscopic- visible to the naked eye Histopathologic/ microscopic- visible under a microscope Clinical features/presentation: signs and symptoms Investigations: correlated with clinical features to arrive a diagnosis Treatment and management Prognosis: fate of the disease and patient  pathology Epidemiology Etiology (the cause leads to the beginning of pathogenesis) Pathogenesis Morphological or chemical alteration Clinical features (signs and symptoms) Investigations and Diagnosis  Pathology Pathology can be classified according to range of study (and this mainly applies to anatomic pathology due to historical effects) into : - General (Basic) Pathology - Systemic (Specific)Pathology This classification is usually used in academic fields and academic textbooks.  Pathology Can also be classified according to uses and practice field into : Experimental Pathology Clinical (Diagnostic) Pathology  Main human materials used in Pathology Excretion and secretions: - urine and faeces - sputum Blood: - blood cells - plasma - serum Effusions and exudate: - Pleural and ascitic fluid Cytology samples Biopsies and organ resections : - needle biopsy, endoscopic biopsy, incisional biopsy and surgically resected organs  Methods used in Pathology Morphologic – Gross observation and description – Microscopic examination (histo & cyto pathology) : light, fluorescence and electron microscopy (scanning & transmission) Molecular/Biochemical/Cytogenetic – Applied clinical and research methods Immunologic/ Serologic – Serum, plasma, cell suspensions, tissues Microbiologic – Cultures, biochemical assays, immunologic Some instruments & techniques used in diagnostic Pathology LIGHT MICROSCOPY IMMUNOFLUORESCENCE MICROSCOPY ELECTRON MICROSCOPY Egor Length meter(m), millimeter(mm) =10-3m, micrometer(µm) =10-6 m nanometer(nm) = 10-9 m, picometer(pm) = 10-12 m. Angstrom = 10-10 m Sizes of living cells and components atom - 0.1 nm molecules - 0.5-10 nm viruses - 30-80 nm bacteria - 2 µm animal and plant cells- 10-30 µm  The branches/subdivisions of pathology: 1. Histopathology: study of tissue biopsied/excised from body to diagnose diseases. 2. Cytopathology: study of cell morphology, exfoliated or aspirated from body to diagnose diseases. 3. Immunohistochemistry: a special staining procedure is used to detect special antigens in the tissue to arrive diagnosis. 4. Hematology: study of blood, blood cells and bone marrow, used in the diagnosis of hematolymphoid disorders (e.g. anemias & leukemias). 5. Chemical pathology/ clinical biochemistry: study and diagnosis of disease from the chemical changes in tissues and fluids (e.g. blood, urine, etc).  The branches/subdivisions of pathology: 6. Microbiology: study of infectious diseases and the diagnosis of causative organisms. 7. Immunology: study and analysis of the immune system of the body. 8. Toxicology: study of various poisonous and toxic substances. 9. Cytogenetics (clinical genetics): is a study of chromosomes and genes abnormalities. 10. Molecular pathology: e.g. fluorescent in situ hybridization, Southern blot tests etc. 11. Autopsy (Forensic pathology): sub-specialty of pathology which involves examining a dead body (e.g. investigation of death in suspicious circumstances). a) Histology b) Cytology a) Histology under b) Cytology under  Pathology an extremely exciting medical specialty helping to Understand & treat the diseases via diagnostic service for all other specialties  The Tree of Medicine Pathology is the scientific basis for clinical medicine Pathology gives clinical purpose to basic sciences and scientific research the approach to the patient’s illness clinically is based on the following sequence of steps: Diagnosis (Patient's history, Examination, Investigations), Treatment & prognosis  PATHOLOGY (As is our pathology so is our practice.) (What the pathologist thinks today, the physician does tomorrow.) Sir William Osler  Pathology (Withoutpathology, there is no medicine!) Birger Fredrik Motzfeldt Laane. M.D. Physician and Consultant Pathologist Introduction to Basic Pathology course LEARNING PATHOLOGY: There are two apparent difficulties that face the new student of pathology: language (terminology) and process. Pathology, like most branches of science and medicine, has its own vocabulary of special terms: these need to be learnt and understood not just because they are the language of pathology but because they are also a major part of the language of clinical medicine. The student must not confuse the learning of the language with the learning of the mechanisms of disease and their effects on individual organs and patients. For example, the term “hyperplasia” means an increase in the size of an organ due to the proliferation of its constituent cells; this definition must be learnt before the student attempts to learn about the process of hyperplasia. Introduction to Basic Pathology course Learning Resources: a) Textbooks: – Robbins. Basic Pathology. Wheater's (Required Text Book) – Robbins. Pathologic basis of disease. (Reference) b) laboratory – Glass slides, images, virtual microscopy – Museum for gross examination of organs, virtual gross specimens Introduction to Basic Pathology course The objectives of this course are to : 1. provide the basic concepts and principles of cell injury, inflammatory and repair processes, circulatory disorders, infections, cell growth and differentiation, and neoplasia. 2. Provide the basic blocks of knowledge for students to understand the pathological processes that leads to various presentations of diseases as well as the procedures or methodology of confirming diagnosis. Introduction to Basic Pathology course General (basic) Pathology Outline 1: Cellular Adaptations and Injury: Pathological adaptations, degeneration, death and Aging 2: Acute and Chronic Inflammation 3: Tissue Regeneration and Repair 4: Hemodynamic Disorders 5: Growth disorders & Neoplasia THANKS