L2 Acute Inflammation Flashcards
What is acute inflammation?
The reaction of vascularized tissue to injury
What are the components of the acute inflammation process?
- Pathogen/injury
- Host inflammatory cells
- Complement/coagulation cascades
- Chemokines/cytokines
The immediate tissue reaction of acute inflammation is characterized by the accumulation of what three things?
- Fluid
- Plasma proteins
- Innate immune cells
What are the four major causes of inflammation?
- Infections
- Tissue necrosis
- Foreign bodies
- Immune reactions
How are antigens recognized by the innate immune system?
DAMPs (intracellular components) and PAMPs (microbes) bind to TLRs and other recognition receptors on monocytes
What is the inflammasome?
A multi-protein complex characterized by the activation of caspase 1, which ultimately leads to the activation of IL-1
What are lipopolysaccharides?
Components of Gram-negative bacteria cell wall
TLR are associated with ___.
CD-14
What helps mediate vasodilation by increasing flow and vascular permeability?
Nitric oxide
What are the three steps of inflammatory effects on the blood vessels?
- Vascular dilation and increased blood flow (erythema and warmth)
- Extravasation of plasma fluid and proteins (edema)
- Leukcoyte emigration and accumulation
What are the four steps of neutrophils crossing the endothelial cell border?
- Margination/rolling
- Integrin activation
- Stable adhesion (also flattening)
- Migration
What cytokines increase all adhesion molecules?
IL-1, IL-6, TNF-alpha (inflammatory cytokines)
How do PMNs move from a blood vessel to the point of injury?
Chemotaxis (movement along a chemical gradient)
After the neutrophil migrates, what happens?
Degranulation, which triggers recruitment of monocytes (phase 2); this also triggers inhibition of neutrophils (phase 3)
What is the most numerous leukocyte in circulation and the signature cell of acute inflammation?
Neutrophils (PMNs)
How are neutrophils able to respond rapidly to a pathogen?
Cytokines and growth factors signal to the marrow to release more neutrophils; they release mature and slightly immature but functional PMNs.
What is left shift/bandemia?
The presence of bands (slightly immature PMNs) in the blood
What are the 5 major functions of a neutrophil at the site of injury?
- Phagocytosis
- Recognition/attachment (complement)
- Degranulation
- Killing/degradation
- NETs
What is the largest leukocyte in the blood?
Monocytes
What are histiocytes?
Monocytes that exit into tissue
Lack of TLR or phagocytic receptor activation leads to what three effects?
- Decreased pro-inflammatory mediator synthesis and release
- Macrophage sensing this
- Predominant cytokines become TGF-beta and IL-10
What are the four categories of acute inflammation morphology?
- Serous
- Fibrinous
- Suppurative/abscess
- Ulcerative
Which morphology of acute inflammation involves fluid with larger molecules dominated by fibrinogen?
Fibrinous
Which morphology of acute inflammation involves protein poor transudate from capillary to a space peritoneal, pericardial, or pleural?
Serous
