Cellular Response Adaptive Disturbances of growth Inflammation and repair Immune response Non Adaptive Degeneration Neoplasia Dysplasia Necrosis

NFLAMMATION INFLAMMATION

Definition  -it’s a body response against injury, it’s a first line of defense.  -Protective adaptive tissue response to injury.

Causes of Inflammation: By injurious agents called irritants. It are different types: 1-Living Irritants: bacteria, virus, parasites. : 2-Non Living Irritants a-Chemical: Acids, alkalis and poisons. b-Physical: Heat, cold, ionizing radiation. c-Mechanical: Trauma, cut. 3-Antigens: cause allergic inflammation.

Mechanism: 1. Vascular response 2.Cellular response 1. Vascular Response A-Vasodilatations of arterioles  in local blood flow  redness and hotness = (hypraemia). B-Increase in capillary permeability  leakage of fluid  local swelling. C-Release of mediators  pain.

1- inflammatory reaction “dilated blood vessels” The widening of blood vessels resulting from relaxation of smooth muscle cells in vessel walls

Mechanism: 2. Cellular Response: -Margination of WBCs. -Emigration (Diapedesis). -Chemotaxis. -Phagocytosis.

Cellular Response Margination: The polymorphnuclear leucocytes leave the blood and adhesion to the margin of the endothelial lining of the capillaries. Emigration :The polymorphnuclear leucocytes pass between the endothelial cells through the vessels wall by amoeboid movement into damage tissue.

Cellular Response Chemotaxis: Is the directed movement of the polymorph-nuclear leucocytes and macrophages in the area of inflammation. Phagocytosis: Is the ingestion and destruction of the foreign particles by the phagocytic inflammatory cells.

2- Margination of WBC’s: PMN move to the peripheral B.V & adherent to endothelium B.V wall,this process called "Margination of WBC’s

3- Emigration of WBC’s PMN or WBCs migration from vessels lumen into area of tissue damage, this process called" Emigration of WBC’s"

Inflammation types: 1- acute. 2- chronic. 3-sub-acute.

Inflammation types: 1- Acute inflammation: Sudden onset and short duration. -Cellular response  Polymorphnuclear leucocytes, pus cells and macrophages. - Vascular response  Numerous, thin walled, dilated blood vessels.

4- Acute inflammatory cells: Mainly we see PMNL & small amount of macrophages. PMNL= WBCs refer to neutrophil,cytoplasm contain fine violet granules,several lobes of nucleus, Pus cells= dead PMN lymphocytes or dead neutrophil. Machrophages=usually seen in acute & chronic inflammationl, Function of machrophages:1-phagocytosis &killing of bacteria. 2-phagocytosis of necrotic debris. 3-formation of giant cells.

Inflammation types: 2- Chronic Inflammation: Gradual onset and prolonged duration ( connective tissue formation). -Cellular response  Lymphocytes, macrophages, plasma cells and giant cells. - Vascular response  Few, thick walled, narrow blood vessels.

Inflammation types: 3- Sub-acute Inflammation: in between the acute and the chronic

5- chronic inflammatory cells Lymphocytes: WBCs, distinguished by dark blue round nuclei & small amount of cytoplasm. Plasma cells :WBCs, it is mature B-cell,identified by extensive basophilic cytoplasma & small eccentric nuclei( specific seen in chronic inflammation),it is produce large antibodies Fibroblast: is type of cell synthesizes C.T &plays critical role in wound healing Foreign body giant cell: is fused macrophages which are generated in response to present large foreign body, nuclei are arranged in disorganized manner. Langhans giant cell: is fusion of macrophages & contain arranged in horse shoe- shaped pattern in cell periphery, found in granulomatous & tuberculosis conditions.

6- chronic inflammatory cells Mainly we have Plasma cell,lymphocytes.&Fibroblast cells to form

7- chronic inflammatory cells: Mainly plasma cell,small amount of lymphocytes,macrophages & fibroblast cells to form C.T

8- Giant cell ( langerhan’s) specific : Atypical langhans giant cell formed by fusion of macrophages in tuberculosis granuloma,contain nuclei horse shoe-shaped

9- Giant cell (foreign body) non- specific: Giant cell,nuclei arranged in disorganization pattern,fibroblast & few lymphocytes.

10- Acluster of giant cells around (foreign body) : A cluster of giant cells around (foreign body )&number of lymphocytes.