8. ACUTE INFLAMMATION-
VASCULAR CHANGES
IMPORTANT TO BRING ANTIBODIES AND
LEUCOCYTES
1. VASODILATATION
EARLIEST EVENT
ARTERIOLES- OPENING OF CAPILLARIES
INCREASED BLOOD FLOW- RUBOR AND CALOR
2. INCREASED PERMEABILITY
3. STASIS
9. Increased Vascular Permeability (Vascular
Leakage)
Contraction of endothelial cells resulting in
increased interendothelial spaces is the most
common mechanism of vascular leakage.
10. VASCULAR CHANGES-INCREASED
PERMEABILITY-MECHANISMS
FORMATION OF ENDOTHELIAL GAPS IN
VENULES
RAPID,SHORT LIVED
Agent: Histamine,bradykinin
MECHANISM: Phosphorylation Of Cytoskeletal
Proteins Contraction
IMMEDIATE TRANSIENT RESPONSE
12. VASCULAR CHANGES-INCREASED
PERMEABILITY-MECHANISMS
DIRECT INJURY
IMMEDIATE SUSTAINED RESPONSE
ALL LEVELS
NECROTIZING INJURIES (e.g.SEVERE BURN)
13. VASCULAR CHANGES-INCREASED
PERMEABILITY-MECHANISMS
DELAYED PROLONGED LEAKAGE
VENULES,CAPILLARIES
THERMAL INJURIES,X-RADIATION
AFTER 2-12 HOURS,LASTS FOR HOURS OR DAYS
14. Neutrophils that adhere to the endothelium during
inflammation may also injure the endothelial cells
and thus amplify the reaction.
15. VASCULAR CHANGES-INCREASED
PERMEABILITY-MECHANISMS
LEUCOCYTE MEDIATED ENDOTHELIAL
INJURY
DELAYED PROLONGED RESPONSE
COMMON IN GLOMERULI AND LUNGS
16. VASCULAR CHANGES-INCREASED
PERMEABILITY-MECHANISMS
INCREASED TRANSCYTOSIS
ACROSS ENDOTHELIAL CYTOPLASM
INCREASE IN NO: AND SIZE OF TRANSENDOTHELIAL
CHANNELS
LEAKAGE FROM NEW BLOOD VESSELS
IMPORTANT DURING EARLY PHASES OF HEALING
17. VASCULAR CHANGES-
INCREASED PERMEABILITY
ESCAPE OF PROTEIN RICH FLUID AND BLOOD
CELLS - FORMATION OF EXUDATE
TRANSUDATE
FLUID WITH LOW PROTEIN
DUE TO OSMOTIC OR HYDROSTATIC IMBALANCE
VASCULAR PERMEABILITY INTACT
18. Transcytosis:
may involve channels consisting of interconnected, uncoated
vesicles and vacuoles called the vesiculovacuolar organelle:
located close to intercellular junctions.
19. EXUDATE Vs TRANSUDATE
Exudate Transudate
Protein content High Low
Cells & debris High Low
Specific gravity > 1.020 < 1.012
Cause vascular hydrostatic
permeability pressure;
osmotic pressure
Associated with Inflammation
Exudate Transudate
20.
21. Responses of Lymphatic Vessels
lymph flow is increased and helps drain edema fluid,
leukocytes, cell debris, as well as microbes.
Lymphatic vessels also proliferate.
+/-(lymphangitis),+/-(lymphadenitis).
Inflamed lymph nodes are often enlarged because of
hyperplasia of the lymphoid follicles and increased
numbers of lymphocytes and macrophages. This
constellation of pathologic changes is termed
reactive, or inflammatory, lymphadenitis