DR .HALA BADAWI LECTURER OF PATHOLOGY Inflammation DR .HALA BADAWI LECTURER OF PATHOLOGY

INFLAMMATION DEFINITION: Inflammation is the reaction of vascularized living tissue to local injury. It is a series of vascular and cellular reactions aiming to protect the body against the injurious agent . TYPES: -Acute: sudden onset and short duration ( hours - days) -Chronic: gradual onset and long duration ( days -years)

INFLAMMATION CAUSES: Living irritants Bacteria, viruses, parasites and fungi Non-living irritants Physical, chemical and mechanical Antigens

ACUTE INFLAMMATION Caused by an irritant of short duration of action The tissue response is rapid i.e. sudden onset Inflammation lasts for days or weeks Characterized by presence of fluid exudate and cellular exudate mainly polymorph-nuclear leucocytes

CARDINAL SIGNS AND SYMPTOMS OF ACUTE INFLAMMATION REDNESS HOTNESS SWELLING PAIN LOSS OF FUNCTION

Major events in inflammation Cellular events Vascular events Vasodilatation of arterioles and capillaries Increased blood flow Slowing of blood stream Increased capillary permeability Margination of leucocytes Emigration of leucocytes Emigration of monocytes Chemotaxis: (directed movement towards area of inflammation) Phagocytosis: (engulfment of bacteria and necrotic tissue) Formation of Inflammatory Fluid exudate

Vascular Events in inflammation Vasodilatation of arterioles and capillaries Increased blood flow Slowing of blood stream Increased capillary permeability

Cellular Events in inflammation Margination , Emigration of neutrophils & monocytes Chemotaxis & phagocytosis

Phagocytosis, Killing & degradation

Chemical Mediator of Inflammation

CHEMICAL MEDIATORS ACTIONS Bind to specific receptors on the cells Histamine Prostaglandins C3a & C5a Vasodilatation Increase vascular permeability Histamine, kinins, leukotriens Chemotaxis Leukotriens & lysosomal components

The Inflammatory Fluid Exudate Function: It dilutes bacterial toxins and chemical irritants. It brings antibodies to the area of inflammation. It brings the chemical mediators derived from plasma to the area. It contains fibrinogen which changes to fibrin by activation of clotting system. Fibrin helps in localization of inflammation by surrounding the area . Fate: Fluid exudate is absorbed by lymphatics.

Fate of Acute inflammation Complete resolution Healing by scarring Progression and spread: (direct, lymphatic & blood spread) Chronicity

TYPES OF ACUTE INFLAMMATION SUPPURATIVE INFLAMMATION NON-SUPPURATIVE INFLAMMATION

I- SUPPURATIVE INFLAMMATION Types: II- Diffuse Supp. Inflamm. Cellulitis, Suppurative appendicitis, Suppurative cholecystitis, Suppurative peritonitis, Suppurative meningitis …etc. I-Localized Supp. Inflamm. Abscess, furuncle, carbuncle

I- LOCALIZED SUPPURATIVE INFLAMMATION Abscess carbuncle furuncle

Abscess Definition: Cavity containing pus (pus is formed of fluid exudate, fibrin,pus cells, polymprph, macrophages, necrotic tissue and bacteria)

Abscess Fate of abscess: Small abscess: Pus may be absorbed followed by healing Large abscess: Should be evacuated, spontaneous or surgical

Abscess Complication of abscess: Ulcer (local defect on the surface) Sinus (blind end tract) & Fistula (tract with two openings) Hemorrhage & gangrene Spread of infection Ulcer Sinus Gangrene

II- DIFFUSE SUPPURATIVE INFLAMMATION Acute supp. appendicitis Suppurative meningitis Diffuse sup.cholecystitis Cellulitis Cellulitis

NON-SUPPURATIVE INFLAMMATION Catarrhal inflammation: e.g.common cold Pseudo-membranous inflam.: e.g.diphtheria Fibrinous inflammation: e.g. fibrinous pericarditis, fibrinous pleurisy, fibrinous peritonitis. Serous inflammation: e.g. burns Haemorrhagic inflammation Gangrenous (necrotizing) inflammation Allergic inflammation

NON-SUPPURATIVE INFLAMMATION Fibrinous pericarditis Fibrinous pleurisy Fibrinous pericarditis Gangrenous inflammation Haemorhagic pericarditis. Fibrinous peritonitis

CHRONIC INFLAMMATION Characterized by: Mild irritant with a prolonged action Tissue response is gradual and prolonged (mild vascular dilatation and congestion) Tissue destruction is progressive and gradually replaced by fibrous tissue with thickening and narrowing of blood vessels (endarteritis obliterans) Scanty fluid exudate

Chronic Inflammatory Cellular Exudate Composed of: Lymphocytes Plasma cells Macrophages Giant cells Esinophils in parasitic and allergic inflammation.

Types of Chronic Inflammation 1- Chronic non-specific inflammation Different irritants produce inflammatory reaction of the same microscopic picture 2- Chronic specific inflammation Each irritant produces inflammation of a characteristic microscopic picture

Chronic non-specific inflammation

Granuloma Definition: A type of chronic inflammation characterized by focal accumulation of large number of macrophages together with lymphocytes, plasma cells, giant cells and fibroblasts forming tiny granules

Types of Granulomas 1-Infective granuloma a. Bacterial e.g.TB, leprosy & syphilis b. Parasitic e.g. Bilharziasis c. Fungal e.g. madura foot 2-Non-infective granuloma a. Silicosis and asbestosis b. Foreign body granuloma 3-Granuloma of unknown cause Sarcoidosis

Tuberculous granuloma of the lung