W5 Acute Inflammation Final

INFLAMMATION Workshop 6

INFLAMMATION Definition: The inflamation represents the common response of tissues to different injurious agent. Depending on persistence of the agents and of the type of tissue reaction inflammation could be: - ACUTE; - CHRONIC.

ACUTE EXUDATIVE INFLAMATION Is a rapid response to an injurious agent (hours or days) and implies three major changes: cellular, umoral and vascular

Vasculo-cellular changes in the inflammatory focus Vascular changes  Changes of vascular caliber: --

transitory vasoconstriction;

- vasodilation with the opening of the capillaries.

 Changes of the blood circulation speed: - Diminution of the blood flow; - transudate.

 Changes in the vascular permeability: - exudate (rich in proteins).

Cellular changes  Leukocyte extravasation: - margination and rolling; - adhesion and diapedesis; - migration in tissues.

The neutrophil  It is the characteristic element of acute inflamaion  Represents 70% from circulating leukocytes; Coloraţia MGG

MGG

 It has a polilobated nucleus (lsegmented leukocyte);  It contains 2 types of neutral granules : - azurophile granules (lysosomes); - specific granules (alkaline phosphatase , lactofferin, lisosime and collagenase).

 They have a very short life, of about 1-3 days  By destruction they release the lysosomal enzimes.

ME

The macrophage  It is the cell derived from monocyte;

 Appears in the inflammatory focus after the neutrophil ;

Monocit (coloraţia MGG)  It presents : - reniform nucleus; - the cytoplasm is abundant: pinocytosis vacuoles ; mitocondria; lisosomes secretory granules.

ME

Diapedesis neutrophil

CLASSIFICATION OF ACUTE EXUDATIVE INFLAMATION  SEROUS  SERO-FIBRINOUS

 FIBRINOUS  PURULENT 

CATARRHAL

 HEMORRHAGIC

SEROUS INFLAMMATION The serous exudate – increased fluid component( rich in proteins: în proteine: serines and globulins).

Serous alveolitis In the alveolus walls :  congestion of parieto-alveolar capillaries

 In alveolar lumen: serous exudate  eosinophilic fluid;  a few neutrophils;  eritrocytes;  variable amount of bacteria. Coloraţia HE

FIBRINOUS INFLAMMATION Fibrinous exudate – rich in fibrin (by precipitation of fibrin as a network in the inflammatory focus).

Fibrinous alveolitis :  In alveolus walls: – congestion of parieto-alveolar capillaries  In alveolar lumen:    

Fibrinous exudate as a network; neutrophils; eritrocytes; Infectious agents. Mallory Stain

FIBRINOUS INFLAMMATION Fibrinous pericarditis  On the surface of epicardium:

 Intense eosinophilic exudate;  neutrophils;  eritrocytes.  Epicardium:

 vascular congestion;  neutrophils.

Coloraţia HE

PURULENT INFLAMMATION The purulent exudate is constituted by:      

neutrophiles; Macrophages; Eritrocytes; Necrotic debris; Fibrin; Bacteria.

The purulent inflammation can be: DIFFUSE LOCALISED

Frotiu puroi

DIFFUSE PURULENT INFLAMMATION Purulent Leptomeningitis  The meninges is diffusely thickened – –

by:

purulent exudate; vascular congestion.

 The vessels : – leukocyte margination and diapedesis

HE HE Coloraţia

Purulent Leptomeningitis – leukocyte margination and diapedesis

HE staining

LOCALISATED PURULENT INFLAMMATION (abscess)

• The abscess: – localisated purulent Inflammation;

•

Types – Recent – Chronic

Recent cerebral abscess • Centrally: – purulent exudate;

• At periphery: – The fibrin wall.

Coloraţia HE

LOCALISATED PURULENT INFLAMMATION Cronic hepatic abscess • Centrally: cavity that contain • purulent exudate;

 At the periphery: wall = pyogenic membrane Interior – network of fibrin - Exterior - connectivevascular tissue

HE Staining