Inflammation Flashcards
What is inflammation?
- Complex reaction in viable vascularised tissues to sublethal cellular injury
- A protective response geared towards removing the causes and consequences of the injury
- Sets stage for potential healing
- Tightly regulated process consisting mainly of leukocyte and vascular responses
- Triggered by various cell types and soluble mediators
Name the cell types involved in inflammation
- Neutrophils
- Macrophages
- Lymphocytes
- Eosinophils
- Mast cells
Name soluble factors involved in inflammation
- Antibodies
- Cytokines
- Complement system
- Coagulation system
What is acute inflammation?
A rapid non-specific response to cellular injury
- Orchestrated by mediators released from injured cells
- Leukocyte and vascular response
What is chronic inflammation?
Inflammation of prolonged duration in which inflammation, tissue injury and attempts at tissue repair coexist.
- May arise from acute inflammation
- May arise as insidious, low-grade smouldering inflammation
- Persistent infection (mycobacteria, fungi, parasites, viral)
- Prolonged exposure to toxins
- Autoimmunity
- Foreign body (silica)
TRUE OR FALSE:
Granulomatous inflammation is a specific subtype of acute inflammation
FALSE
It is a specific subtype of CHRONIC inflammation
Why is an understanding of inflammation important?
Allows:
- Prediction of sequelae and complications of inflammatory reactions
- Intervention to prevent or reduce adverse effects
Name disease states that involve inflammation
- Infections
- Autoimmune diseases
- Hypersensitivity reactions
- Trauma
- Chronic granulomatous diseases
- Chronic fibrosing diseases
TRUE OR FALSE:
Inflammation may contribute to disease states that are not primarily inflammatory
TRUE
E.g. atherosclerosis, type II diabetes, cancer
How is acute inflammation recognised on examination?
- Rubor (redness)
- Calor (heat)
- Tumor (swelling)
- Dolor (pain)
- (Loss of function)
NOTE: these features appear quickly
What are the 3 main components of acute inflammation?
- Alteration in the calibre of blood vessels to increase flow (vasodilation)
- Structural changes to the microvasculature to allow proteins and leukocytes to leave the circulation (swelling)
- Emigration, accumulation and activation of leukocytes at the focus of injury
What is vasodilation induced by in acute inflammation?
Several mediators including histamine and nitric oxide (affect vascular smooth muscle)
Vasodilation is one of the earliest manifestations. What is it quickly followed by?
An increased permeability of microvasculature
Increased diameter and loss of fluid slow down flow and lead to stasis
Where is the richest source of histamine?
In mast cells
What are the causes of increased vascular permeability?
- Histamine and nitric oxide
- Endothelial cells contract –> increased interendothelial spacing
- Endothelial cell injury (burns, toxins)
- Leukocyte-mediated vascular injury (late stage inflammation)
- Increased transcytosis
- Vascular endothelial growth factor (VEGF) increases transfer of material across cells