introduction

INTRODUCTION TO PATHOLOGY

Examinations Throughout The Year.midyear, written 30 marks (MCQs & essays) .final, 70 marks -written, 40 marks (MCQs & essays) -practical, 20 marks (data show, glass slides, gross specimens) -general assessment during practical sessions, 2 marks -oral, 8 marks

Aim In Studying Pathology.identify different lesions (diseases) .label etiologic factor (s) for each lesion.understand pathogenesis of each lesion.correlate morphological changes with clinical features for each lesion.plan treatment for each lesion.assess prognosis of various lesions.help layout preventive measures for each lesion

Definition .pathology can be defined as,  -study of structural, biochemical, & functional changes in cells, tissues, & organs that underlie disease  -study of causes & effects of disease.pathology is the discipline that bridges basic sciences & clinical practice

Disease .is variation from norm in structure &/or function of any organ example, pneumonia, structural changes in the lung>disturbance of function


Aspects Of Disease .etiology .pathogenesis.biochemical & structural alterations.functional consequences.diagnosis .treatment.prognosis.prevention

Etiology .is the cause of disease -genetic cause -environmental cause

Pathogenesis .sequence of events in response of cells or tissues to etiologic agent, from initial stimulus to ultimate expression of disease .examples -viral infection-proliferation of viruses inside cells>structural & functional changes in cells -bacterial infection-release of toxins which destroy cells



Biochemical And Structural Alterations.assays of various chemicals in blood & body fluids.structural alterations -molecular analysis .DNA changes -morphologic changes  .macroscopic, (gross) .microscopic, (light & electron)

Functional Derangements.end results which lead to clinical manifestations, (symptoms & signs)

Diagnosis And Treatment .identification of morphologic changes (gross & microscopic examination of cells & tissues) .utilization of chemical, molecular, microbiologic, & immunologic techniques

Prognosis.is outcome of diseasePrevention.golden rule is “prevention is the best medicine”

Branches Of Pathology Histopathology & Cytopathology Hematology Chemical pathology Microbiology Immunology Forensic pathology Clinical genetics

Histopathology .is the study of tissue morphology -grossly by inspection for any change in size, shape, color, or presence of any abnormality -microscopically by using light microscope, (structural changes), & electron microscope, (ultra-structural changes)


Divisions of Histopathology.general pathology -focuses on fundamental cellular & tissue responses to various stimuli.systemic pathology -deals with particular responses of specialized organs

Cytopathology .is the study of cell morphology, by using smears (cells put on slides) .examples of smears -uterine cervical -bronchial brush & wash -sputum -fluid aspirate -cavity fluid


Biopsy .is a piece of tissue taken from living body .types -surgical (incisional or excisional) -through endoscope or laparoscope



Autopsy .is a piece of tissue taken from dead body during postmortem examination


How To Deal With A Biopsy.the biopsy should be fixed in proper fixative like 10% formalin to prevent autolysis, (to prevent digestion of tissue by its own enzymes).put in proper labeled container.sent to the laboratory with attached request form filled with information -patient’s name, age, & sex -relative history & operative data about the disease (lesion)