Inflammation Lecture 1 PDF

General Pathology INFLAMMATION; Lecture 1 Dr. Farasin R. Mohammed; Lecturer MBCHB;FIBMS; FRCPath(pathology)  Inflammation – Definition – Types – Mechanism Mediators of inflammation Morphologic patterns of acute inflammation Out come of acute inflammation Chronic inflammati...

General Pathology INFLAMMATION; Lecture 1 Dr. Farasin R. Mohammed; Lecturer MBCHB;FIBMS; FRCPath(pathology)  Inflammation – Definition – Types – Mechanism Mediators of inflammation Morphologic patterns of acute inflammation Out come of acute inflammation Chronic inflammation systemic effects of inflammation. Definition & benefits of normal inflammation Definition of inflammation: is a protective response of vascularized tissue to injury, induced by chemical mediators produced by host cells, normally controlled and self limited. Benefits of inflammation: 1- eliminate the initial cause of cell injury (microbes and toxins) and its consequences (necrotic cells and tissues), so inflammation will be eliminated by their elimination and 2- initiate the process of repair What the conditions of abnormal inflammtion: A- Excessive inflammation 1. In cases of prolonged or severe infections 2. Inappropriately against self-antigens called autoimmune diseases or against usually harmless environmental antigens causing allergy  2- Defective inflammation Too little inflammation, which is typically manifested by increased susceptibility to infections, is most often caused by a reduced number of leukocytes resulting from replacement of the bone marrow by cancers and suppression of the marrow by therapies for cancer and graft rejection  steps of normal inflammatory response (1)Recognition of the injurious agent, five Rs (3)Recruitment (2) of leukocytes, emoval of the agent, (4)Regulation (control) of the response, (5)Resolution (repair).  Types of inflammation Acute and chronic What is the difference between them?? External manifestation of inflammation or its cardinal – heat (calor), signs are: – redness (rubor), – swelling (tumor), – pain (dolor), – loss of function (functio laesa). More promine nt in acute inflamm ation  Nomenclature of inflammatory reaction Inflammation is named by adding suffix itis to organ or tissue involved Examples: Gastritis, appendicitis, tonsilitis, duodenitis, gingivitis, pulpitis, periodentitis. Exceptions: Pneumonia which is inflammation of the lung & Pleurisy which is inflammation of pleura. Causes of Inflammation 1. Infections 2. Trauma: physical or chemical 3. Tissue necrosis: like myocardial infarction 4. Foreign bodies like sutures 5. Immune reactions (hypersensitivity reactions)  Components of acute inflammation The main components of inflammation are a vascular reaction and a cellular response; both are activated by mediators that are derived from plasma proteins and various cells  involved in acute inflammation and their role  Events of acute inflammation are 1. dilation of small vessels leading to an increase in blood flow 2. increased permeability of the microvasculature enabling plasma proteins and leukocytes to leave the circulation 3. emigration of the leukocytes from the microcirculation, their accumulation in the focus of injury, and their activation to Vascu Cellul eliminate the offending agent lar ar even even ts ts Reaction of blood vessels in acute inflammation 1- Arteriolar vasodilation >>> leads to the opening of new capillary beds in the area increasing blood flow leading to heat and redness (erythema) at the site of inflammation. 2- Increased vascular permeability of the microvasculature, with the outpouring of protein- rich fluid (an exudate) into the extravascular tissues. 3- Stasis of blood flow as a result of increase blood viscosity. 4- Margination of leukocytes (principally neutrophils) which begin to accumulate along the  The result of acute inflammation is escape of fluid, proteins, and blood cells from the vascular system into interstitial tissues or body cavities; known as exudation What is exudate??? Transudate??? Oedema And Pus or purulent exudate  Exudation >> The escape of fluid, proteins, and blood cells from the vascular system into the interstitial tissue or body cavities Edema denotes an excess of fluid in the interstitial tissue or serous cavities; – Exudate is an extravascular fluid that has a high protein concentration and contains cellular debris. Pus, a purulent exudate, is an inflammatory exudate rich in leukocytes (mostly neutrophils), the debris of dead cells and, in many cases, microbes.