Block 4 Flashcards
Cell Derived : Newly synthesized Arachidonic Acid Metabolites
Damage to cell membranes–> ?
that acts on cell membranes–> releasing what?
- Damage to cell membranes → activation of Phospholipase A2
that acts on cell membranes → releasing Arachidonic Acid (AA)
Cell Derived : Newly synthesized Arachidonic Acid Metabolites
Two major classes of enzymes then act on AA to produce
metabolites?
- Cyclooxygenase (Cox 1 and 2)
- Prostaglandins and prostacyclins
- COX1 constitutive in gut and kidney
- Lipoxygenase
- Leukotrienes (LTs) and lipoxins
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Vasodilation (protective in gut
and kidney), fever and pain,
platelet aggregation inhibition
Prostaglandins/Prostacyclins
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Vasoconstriction and platelet
aggregation (procoagulant)
TXA2(thromboxane)
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Vasoconstriction and
bronchoconstriction
Leukotrienes C-E
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Chemotaxis
L2B4
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Inhibitors of inflammation
Lipoxins
Arachidonic Acid Metabolites act on many cell types and mediate all
step
Corticosteroids (prednisone, dexamethasone) and many Non-Steroidal Anti-inflammatory Drugs
(NSAIDs like meloxicam, phenylbutazone, ibuprofen) act on this pathway
true/false?
true
Arachidonic Acid Metabolites act on many cell types and mediate all
step
-main actions are on endothelium, leukocytes, fibroblasts and induction of acute phase response.
-primarily responsible for the “acute phase response”
Inflammatory Cytokines: IL1,TNFa
? is a complex systemic early-defence system
activated by trauma, infection, stress, neoplasia, and inflammation
Acute Phase Response
Acute Phase Response
When tissue is injured, what secrete cytokines into the bloodstream (e.g.
interleukins like IL-1, IL-6 and TNFα)
local inflammatory cells (neutrophils, granulocytes
and macrophages)
Acute Phase Response
what in response, produces a large number of acute-phase reactants
(e.g. C-reactive protein, complement factors, mannose-binding protein &
ferritin)
The liver
Acute Phase Response
What are the 7 steps that take place?
- Fever
- ↑ sleep
- Pain
- Neutrophilia
- ↓ Appetite (TNF promotes lipid and protein mobilization by
suppressing appetite) - Prolonged production of TNF → cachexia (weight loss and
anorexia – cancer and infection) - Corticotropin and corticosteroids released
- If severe → hypotension, decreased vascular resistance, increased
heart rate and decreased blood pH → shock
Clotting System
The clotting system
and ? are
intimately connected
inflammation
Clotting System
The clotting system is
divided into two
converging pathways–>
what?
→ activation of
THROMBIN and the
formation of FIBRIN
Clotting Cascade
Plasma Derived
intrinsic or extrinsic?
(Intrinsic)
Clotting Cascade
Tissue Derived
intrinsic or extrinsic?
(extrinsic)
Clotting Cascade
-Hageman Factor(F12) activated 2° to exposure of
collagen & basement membrane when
endothelium is damaged
is an example of what?
Plasma Derived (Intrinsic)
Clotting Cascade
- Tissue factor released when sub-endothelial damage
Coagulation Cascade
Fibrinogen Fibrin
- fibrin strands (pink) seen histologically
- framework for repair
is an example of what?
Tissue Derived (extrinsic)
Summary: Acute Inflammation
Causes
are many and include anything that causes cell injury
Summary: Acute Inflammation
Purpose
destroy harmful agents & limit their spread, prepare damaged tissue
for repair
Summary: Acute Inflammation
Cardinal signs of inflammation
Redness, Swelling, Heat, Pain, Loss of function
(vasodilation, ↑permeability, oedema, bradykinin release)
Summary: Acute Inflammation
Chemical mediators from plasma
- Complement - lyses microbes, increases permeability, chemotaxis
- Coagulation - fibrin, production, controls bleeding
Summary: Acute Inflammation
Chemical mediators derived from cells
- Preformed : histamine, serotonin, lysosomal enzymes
- Synthesized : PGs/LK, ROS, cytokines (including chemokines)