Chapter 2: Inflammation, Inflammatory Disorders, and Wound Healing Flashcards
tissue necrosis is always followed by?
acute inflammation – increase in neutrophils
What is the goal of acute inflammation?
eliminate pathogen or clear necrotic debris
How do macrophages deal with gram negative bacteria?
the CD14 receptor on macrophages recognize LPS on outer membrane of gram negs
Describe pathway of TLR’s
Pathogen Associated Molecular Patterns(PAMPs) activate TLR’s on macrophages/lymphocytes causing upregulation of NF-kB which is a nuclear transcription factor that activates immune response genes leading to production of multiple immune mediators
TLR on B-cells importance
They cross link enough receptors to NOT need a second signal!
Arachidonic Acid Metabolites
Arachidonic Acid released from cell membrane by phospholipase A2 and then acted upon by COX or 5-lipoxygenase creating prostoglandins, prostocyclines, thromboxanes(COX) and leukotrienes(5-lipoxygenase)
Mediates vasodilation and increases vascular permeability
PGI2, PGD2, PGE2
mediates pain and fever
PGE2
neutrophil chemoattractants
LTB4, IL-8, C5a
mediate vasoconstriction, bronchospasm, and increased vascular permeability
LTC4, LTD4, LTE4 leukotrienes cause smooth muscle contraction – bronchial muscles, smooth muscle in vessels and pericytes(edema)
Vasodilation occurs at the…
arteriole
increased vascular permeability occurs at…
venule
Mast cells activated by
tissue trauma, complement proteins C3a, C5a or cross linking by IgE
Mast cell immediate response
release histamine – vasodilation and increase permeability
Mast cell delayed response
release leukotrienes
Complement System
Classical Pathway – C1 binds IgG or IgM that’s bound to antigen Alternative pathway – microbial products directly activate Mannose binding lectin pathway - MBL binds to mannose on microorganisms and activates complement
What is important in DIC?
Hageman Factor(Factor XII)
Cardinal Signs of inflammation
Redness(rubor), warmth(calor) both caused by histamine mediated vasodilation Swelling(tumor) also caused by histamine mediated increase in vascular permeability Pain(dolor) mediated by bradykinin and PGE2 which sensitize nerve endings Fever is caused by the release of IL-1 and TNF which increase cyclooxygenase activity in perivascular cells of the hypothalamus which increases local PGE2 synthesis which raises temperature setpoint
Leukocyte margination occurs through?
postcapillary venules! Cells marginate from the center flow to the periphery due to the slow of blood flow from vasodilation
Leukocyte rolling occurs via?
selectin speed bumps upregulated in endothelial cells.Histamine causes release of P-selectin from Weibel-Palade bodies. E-selectin is induced by TNF and IL-1. Interaction of P-selectin and E-selectin causes leukocytes to roll along vessel wall
What does selectin on endothelial cells bind on leukocytes (neutrophils, macrophages, etc.)
Sialyl Lewis X
Leukocyte adhesion to endothelial cells occur via?
upregulation of adhesion molecules, ICAM and VCAM by TNF and IL-1 bind to integrins on leukocytes
What causes upregulation of adhesion molecules?
IL-1 and TNF
What causes upregulation of selectins?
Histamine for P-selectin from Weibel Palade bodies, TNF and IL-1 for E-selectin