Acute Inflammation Flashcards
What is acute inflammation characterized by?
Exudation of fluid and plasma components and emigration of leukocytes, predominantly neutrophils, into the extravascular tissue
Acute inflammation occurs ___ adaptive immunity becomes established
before
What triggers acute inflammation?
- infections
- immune reactions
- blunt and penetrating trauma
- physical or chemical agents
- tissue necrosis
What is the primary phagocyte that arrives early at the site of inflammation, usually within 90 minutes of injury?
neutrophil
The neutrophil count in the blood often ______ greatly during an inflammatory process, especially with bacterial infections.
increases
Once released from the bone marrow neutrophils have a life span on how long?
10 hours
What leukocyte is the largest and constitutes 3-8% of the WBC count?
monocytes
Within __ hours, mononuclear cells arrive at the inflammatory site, and by __ hours, monocytes and macrophages are the predominant cell type.
24
48
Monocytes and macrophages produce potent vasoactive mediators that promote tissue regeneration. List these 5 mediators
- prostaglandins
- leukotrienes
- platelet activating factor (PAF)
- inflammatory cytokines
- growth factors
Do monocytes of neutrophils engulf larger and greater quantities of foreign material?
monocytes
What 3 cell types produce lipid mediators and cytokines that induce inflammation?
- eosinophils
- basophils
- mast cells
When do eosinophils increase in the blood?
- allergic reactions
- parasitic infections
What do the granules of basophils contain?
histamine and other bioactive mediators of inflammation
The binding of basophils and mast cells to the antibody IgE triggers what to happen?
release of histamine and vasoactive agents from the basophil granules
What 3 things does activation of mast cells result in?
- release of preformed contents of their granules
- synthesis of lipid mediators derived from cell membrane precursors
- stimulation of cytokine and chemokine synthesis
What are the 2 components of acute inflammation?
- vascular stage
- cellular stage
What is the vascular stage characterized by?
Vasodilation and changes in blood flow followed by increased vascular permeability and leakage of protein-rich fluid into the extravascular tissues
Which comes first, vasodilation or vasoconstriction?
Vasoconstriction
Vasodilation is most notably mediated by what?
- histamine
- nitric oxide
This increase in vasodilation is quickly followed by increased permeability of the microvasculature, which results in what?
The outpouring of a protein-rich fluid (exudate) into the extravascular spaces
This loss of fluid result in what 3 things?
- an increased concentration of blood constitutes
- stagnation of flow
- clotting of blood at the site of injury
The loss of plasma proteins _____ the intracapillary osmotic pressure and _____ the osmotic pressure of the interstitial fluid. What does this cause?
reduces
increases
Fluid to move into the tissues and produce swelling, pain, and impaired function
What is the benefit of exudation of fluid into the tissue spaces?
it dilutes the offending agent
What causes the increased permeability characteristic of acute inflammation?
Binding of the chemical mediators to endothelial receptors causes contraction of the endothelial cells and separation of intercellular junctions
