ACUTE INFLAMMATION- VASCULAR CHANGES IMPORTANT TO BRING ANTIBODIES AND LEUCOCYTES1. VASODILATATION EARLIEST EVENT ARTERIOLES- OPENING OF CAPILLARIES INCREASED BLOOD FLOW- RUBOR AND CALOR2. INCREASED PERMEABILITY3. STASIS
Increased Vascular Permeability (Vascular Leakage) Contraction of endothelial cells resulting in increased interendothelial spaces is the most common mechanism of vascular leakage.
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
Endothelial injury, resulting in endothelialcell necrosis and detachment
VASCULAR CHANGES-INCREASED PERMEABILITY-MECHANISMS DIRECT INJURY IMMEDIATE SUSTAINED RESPONSE ALL LEVELS NECROTIZING INJURIES (e.g.SEVERE BURN)
VASCULAR CHANGES-INCREASED PERMEABILITY-MECHANISMS DELAYED PROLONGED LEAKAGE VENULES,CAPILLARIES THERMAL INJURIES,X-RADIATION AFTER 2-12 HOURS,LASTS FOR HOURS OR DAYS
Neutrophils that adhere to the endothelium duringinflammation may also injure the endothelial cellsand thus amplify the reaction.
VASCULAR CHANGES-INCREASED PERMEABILITY-MECHANISMS LEUCOCYTE MEDIATED ENDOTHELIAL INJURY DELAYED PROLONGED RESPONSE COMMON IN GLOMERULI AND LUNGS
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
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
Transcytosis:may involve channels consisting of interconnected, uncoatedvesicles and vacuoles called the vesiculovacuolar organelle:located close to intercellular junctions.
EXUDATE Vs TRANSUDATE Exudate TransudateProtein content High LowCells & debris High LowSpecific gravity > 1.020 < 1.012Cause vascular hydrostatic permeability pressure; osmotic pressureAssociated with Inflammation Exudate Transudate
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