inflammation Flashcards
what is inflammation?
Inflammation is the reaction of a tissue and its microcirculation to a noxious stimulus, e.g. microbes, injury or stress.
characteristics of inflammation?
- production of inflammation mediators.
2. moving out of leukocytes to the extravascular tissues.
five signs of inflammation.
- Rubor (redness)
- Calor (heat)
- Tumor (swelling)
- Dolor (pain)
- Functio laesa (loss of function).
components of microvasculature.
- arterial capillaries.
- venous capillaries
- arteriole
- venule
purpose of inflammation.
- Elimination of pathogenic insults
2. Removal of injured tissue component.
CAUSES AND OUTCOMES OF INFLAMMATION.
trigger physiological pathological
purpose consequences
- infection -to eliminate - Autoimmunity
- tissue injury -repairing -tumor growth
- tissue stress -adaptation -change in
homestatic
set point.
stages of inflammation.
- Initiation
- Amplification
- Termination
classes of inflammation mediators according to their origin.
- Plasma derived mediators: derived mediators are derived majorly from complement, kinin or clotting system.
- Cell-derived mediators: are derived from platelets, neutrophils, monocytes, macrophages and mast cells.
Plasma derived mediators.
- C3b and C3bi are opsonins; C5a- a potent chemotactic factor for neutrophils, monocytes..
- Bradykinin- increases vascular permeability, contraction of smooth muscle & dilation of blood vessels.
- Factor Xa and fibrinopeptide- increase vascular permeability and leucocyte exudation.
- Thrombin- leucocyte adhesion and fibroblast proliferation.
Cell-derived mediators.
- Histamine: mast cells, basophils, and platelets; acts via H2 receptor.
- Serotonin: Platelets and enterochromaffin cells. Also in mast cells of rodents.
- Platelet-activating factor (PAF): mast cells, basophils, neutrophils, monocytes, macrophages, endothelial cells, platelets, etc.
- Arachidonic acid metabolites
what are the inducers and functions of histamine mediator?
inducers: 1. Physical injury: cold, heat, and trauma.
2. Cytokines: IL-1, IL-8.
3. substance p.
function: 1. Dilation of the arterioles, increased vascular permeability of the venules.
inducers and function of serotonin mediator.
inducer: 1. The release of serotonin is stimulated when platelets aggregate after contact with collagen.
function: 1. serotonin causes dilation of arterioles and increased vascular permeability of the venules.
Action of Platelet activating factor (PAF).
Actions: Increased vascular permeability, leucocyte adhesion, platelet activation, leucocyte chemotaxis, stimulation and release of other mediators.
TYPES OF INFLAMMATION.
- Acute inflammation: is of relatively short duration.
2. Chronic inflammation: is of long duration.
characteristics of acute inflammations.
- Exudation of fluid and plasma protein
2. Emigration of leucocytes, predominantly neutrophils.