Inflammation Flashcards
Define Inflammation
Dynamic Process of tissue injury that involves a series of events
Protective response - required for healing
Nonspecific
Inflammation…
DOES NOT EQUAL INFECTION
- infection will have inflammation though
Primary Signs and Symptoms
Heat Swelling Redness Pain Disturbed Function
Vascular Changes
- Tissues first response to injury
- Initial phases involve neural mechanisms
- Remaining changes related to plasma and cell derived mediators
- Leads to hyperemia (inc blood flow to the area)
Events of Acute Inflammation
- Control by nervous system
1. Vasoconstriction
2. Vasodilation
3. Increased vascular permeability
4. Emigration of leukocytes
Vasoconstriction
- Neural Control (ANS)
- Arterioles vasoconstric - sphincter btw arteriole and capillary bed is shut down
- Lasts for seconds
Vasodilation
- Move away from ANS and is more nervous system
- Arterioles vasodilate and precapillary sphincter relaxes
- Venous side remains vasoconstricted during this phase
- Capillaries contain more blood
Structure of a capillary
Basement membrane and one cell layer - makes it permeable
Vasoactive Events
A variety of interdependent events are occurring
Cell and plasma derived substances are activated
- As soon as blood hits the tissue in an injured aream variety of mediators are activated and cause vasoactive events to occur - further vasodilation and permeability of capillary walls
Events of Inflammation
- Cells that have been injured release substances that are chemotaxic to inflammatory substances
- Increased blood into area increase the number of leukocytes, platelets, and other substances
- Margination
- Leukocytes move out of the central column and move toward the margins
- Roll along epithelium (inside vascular walls)
- Pavementing
- Cytokines are released by the cells injured
- Activates response within the leukocytes and the endothelial membrane
- Causes adhesion of leukocytes to the endothelial cells
- Emigration
- WBCs move through the epithelial gaps
- Move into the extravascular tissues
1st responders
Neutrophils - go out into tissue to clean debris
RBCs/Platelets
- Begin to stack, known as Rouleaux of RBC
- Platelets become stickier and and take the stacked RBCs to stick to them
- Leads to more viscosity of blood
- Slows blood flow - blood clots form
Primary Mediators of Inflammation
- Histamine
- Serotonin
- Nitric Oxide
- Kinin System
- Complement System
- Clotting System
- AA metabolites
- Plate Activating Factors
Mast Cell found in…
Found in CT
Mast Cell Degranulation Stimulated by…
Direct Injury Binding of IgE Complement System Leukocyte derived proteins Cytokines (interleukins)
Mast Cell Functions When it Degranualtes it…
- Binds IgE
- Releases Hieparin (dec speed of clotting, blood thinner)
- Synthesis and release of:
- Histamine
- Leukotrines and prostoglandins via AA
- Platelet activating facot
- TNF
- Interleukins
Platelets (Thrombocytes)
NOT a cell
Fragmented megakaryocytes
Contain cytoplasmic granules
As the aggregate and adhere, the degranulate
Three primary inclusions (dense, alpha, lysosomes)
Platelets - Dense Granules Release…
Serotonin, histamine - affect smooth muscle contractility - Vasocon of vessel walls - Vasodil of capillary venules Ca and ADP - stickiness
Platelets - Alpha Granules Contain…
Fibrinogen, coagulation proteins, PDGF
Platelets - Lysosomes
Antimicrobial
Histamine
Mast cell = primary source
Dilation and increased vascular permeability
Short term
Serotonin
Released from platelets
Effects similar to Histamine
Sticks around longer though