Introduction to Pathology D2 Lecture Notes PDF

Introduction to Pathology Year/Level: D2 / Semester 1 Dr Mohammad Shahid Iqbal M.D Assistant Professor of Pathology 1 Learning Outcomes By the end of this lecture, the students will know about 1. Course overview 2. Topics of study 3. Assessments and Ass...

Introduction to Pathology Year/Level: D2 / Semester 1 Dr Mohammad Shahid Iqbal M.D Assistant Professor of Pathology 1 Learning Outcomes By the end of this lecture, the students will know about 1. Course overview 2. Topics of study 3. Assessments and Assignments 4. Basic terminology used in health and disease 5. Definition of Pathology 6. Subdivisions of Pathology 2 Pathology: Overview 3 Pathology: Overview 4 Pathology: Overview The course will cover the basic concepts and general mechanisms of cell and tissue reactions and disease processes. This includes the most common etiological factors, pathogenesis, different morphological features and clinical manifestations. The topics include cell injury, cellular adaptations, intracellular accumulations, inflammation, regeneration, tissue repair and healing. We will also address the most common pathology terminologies that are essential for the course. 5 Pathology: Overview Semester 1: Includes Cell injury Types of cellular adaptations Inflammation: Acute, chronic and granulomatous type Tissue repair and wound healing 6 Objectives To understand the major cellular and molecular changes which underlies a general disease process Apply these concepts into understanding of the specific diseases Identifying disease morphologies and outcome and correlating their clinical presentations with the disease process. To recognize the etiology, pathogenesis and morphology of disease phenomenon associated with cell injury, inflammation and tissue repair, To understand the knowledge of microscopic features of the range of normality within tissues as well as the major common pathological processes and patterns of disease 8 Pathology: Overview 9 Pathology: Overview 10 Pathology: Overview Assessment Percentage of Total No Assessment Activities * timing Assessment Score (week )* 1. QUIZ 1 5 OR 6 10% 2. QUIZ 2 9 OR 10 10% 3. LAB REQUIREMENTS Every lab session 15% 4. ASSIGNMENTS Week 13 to 15 10% 5. OSPE Week 16 10% 6. FINAL EXAM Week 17-18 45% *Tentative and as per academic office calendar. 11 Pathology: Overview 12 Introduction to Pathology 13 Introduction to Pathology The word ‘Pathology’ is derived from two Greek words— Pathos (meaning suffering) and logos (meaning study). “scientific study of changes in the structure and function of the body in disease” Pathology consists of the abnormalities in normal anatomy (including histology) and normal physiology owing to disease. ‘Pathophysiology’ (patho=suffering, physiology=study of normal function). Pathophysiology: study of disordered function(i.e. physiological changes) and breakdown of homeostasis in diseases (i.e. biochemical changes). 14 Introduction to Pathology Pathology is the study of the structural, biochemical, and functional changes in cells, tissues, and organs that underlie disease By the use of morphologic, microbiologic, immunologic, and molecular techniques, pathology attempts to explain the whys and wherefores of the signs and symptoms manifested by patients while providing a rational basis for clinical care and therapy. Bridge between the basic sciences and clinical medicine 15 Pathology: Overview What is disease? What is not healthy is disease Health may be defined as a condition when the individual is in complete accord with the surroundings, while disease is loss of ease (or comfort) to the body (i.e. dis+ease) A disease or an illness means a condition marked by pronounced deviation from the normal healthy state. Syndrome (meaning running together) is used for a combination of several clinical features caused by altered physiologic processes. 16  COMMON TERMS IN PATHOLOGY Patient is the person affected by disease. Lesions are the characteristic changes in tissues and cells produced by disease Symptoms: Functional implications of the lesion felt by the patient Physical Signs: Functional implications discovered by the clinician Diagnosis: Clinical significance of the morphologic and functional changes together with results of other investigations help to arrive at an answer to what is wrong 17 COMMON TERMS IN PATHOLOGY Prognosis: what is going to happen Treatment: what can be done about it (How to treat or manage) Prevention: what should be done to avoid complications and spread 18  Aspects of disease process Etiology: cause for a disease (‘WHY’ of a disease). Pathogenesis : mechanisms by which the lesions are produced (‘HOW’ of a disease). Morphology: the appearance of tissue or organ in a disease ; changes recognized by naked eye is ‘GROSS’ morphology and changes studied by microscopy is ‘MICROSCOPIC’ morphology. Clinical manifestation: Signs and symptoms of the disease Disease aspects 20 Pathogenesis:  Morphology: The structural alterations in cells or tissues that are characteristic of a disease and hence diagnostic of an etiologic process Includes Gross and Microscopic examination. Macroscopical (gross) lesions: Abnormality in the tissue can be described grossly or by the naked eye including Location Color Size, Shape, Consistency & Appearance of the cut surface. Microscopy: Abnormal morphological changes described under the microscope. Nonneoplastic lesions: Neoplastic lesions: Inflammatory: acute or chronic Capsule, circumscription Congenital disorders Tumor cells : benign Vs malignant Endocrine deficiencies; Hyper/Hypo If malignant: Infarction Histological type, Infections Grade, Intracellular accumulations Margins, Autoimmune diseases Lymphovascular invasion Status of lymph nodes Subdivisions of pathology 1. General pathology 2. Systemic pathology 24 Subdivisions of pathology General pathology is concerned with the common reactions of cells and tissues to injurious stimuli. Such reactions are often not tissue specific: thus, acute inflammation in response to bacterial infections produces a very similar reaction in most tissues. Systemic pathology examines the alterations and underlying mechanisms in diseases of particular organ systems. 25  Sub-divisions of Pathology General Pathology Systemic pathology Branches of Pathology HISTOPATHOLOGY (Anatomic Pathology) Histopathology, used synonymously with anatomic pathology The study includes structural changes (gross or macroscopic changes), and the changes detected by microscopy, to arrive at the most accurate diagnosis. Modern time anatomic pathology includes sub-specialities such as cardiac pathology, pulmonary pathology, neuropathology, renal pathology, gynaecologic pathology, breast pathology, dermatopathology 27 Branches of Pathology HISTOPATHOLOGY Macroscopic pathology (Gross) Microscopic features 28  Branches of Pathology Histopathology or Anatomic pathology includes the following subdivisions 1. Surgical pathology; It deals with the study of tissues removed from the living body by biopsy or surgical resection 2. Experimental pathology: This is defined as production of disease in the experimental animal and study of morphological changes in organs after sacrificing the animal 3. Forensic pathology and autopsy work : This includes the study of organs and tissues removed at postmortem for medicolegal work and for determining the underlying sequence and cause of death. 29  Branches of Pathology CYTOPATHOLOGY : Study of cells Cells shed off from the lesions (Exfoliative cytology) Cells aspirated from superficial and deep-seated lesions for diagnosis: Fine-needle aspiration cytology (FNAC) 30  Branches of Pathology CYTOPATHOLOGY : FNAC 31  Branches of Pathology CLINICAL PATHOLOGY: Analysis of various fluids including blood, urine, semen, CSF and other body Such analysis may be qualitative, semi-quantitative or quantitative. MOLECULAR PATHOLOGY: The detection and diagnosis of abnormalities at the level of DNA of the cell is included in molecular pathology such as in situ hybridization, PCR etc. These methods are now not only used for research purposes but are also being used as a part of diagnostic pathology reports. 32 Branches of Pathology Next Lecture Introduction to Cell Injury Types of cell injury Mechanism of Cell Injury 34  References 1. Robbins and Cotran Pathologic Basis of Disease; 10th ed. 2021 2. HarshMohan Textbook of Pathology. 7th edition. 35  Thank You Any questions? [email protected] 36