Acute Inflammation Flashcards
Inflammation
Response of living tissue to injury
- continuous
What is the primary delivery system for inflammatory components?
Blood
Acute inflammation
Standardized reaction, early response
- immediate vascular response
- hours to days
- microbes or non-infectious reasons
Chronic inflammation
Alteration of an inflammatory
- weeks to years
- microbes or non-infectious reasons
What is the goal of acute inflammation?
Dilute toxins –> isolate –> eliminate –> repair
What are 4 harmful effects of inflammation?
- persistent cytokine release
- destruction of normal tissue
- swelling
- inappropriate inflammatory response
What are 2 signs of systemic inflammation?
- leukocytosis
- fever
Leukocytosis
Abnormally high number of circulating WBCs
- increased neutrophils, indicative of bacterial infection
- increased lymphocytes associated with viral infections
Fever
Coordinated by hypothalamus and involves wide range of factors
- associated with infectious cause
What are the 5 cardinal signs of inflammation?
- heat: increase blood flow
- redness: hyperemia
- swelling: due to edema
- pain: stretching and distortion of tissues due to edema and chemical mediators
- loss of function: movement inhibited by pain or swelling
What is the first part of the acute response?
Swelling
- if swelling continues then inflammatory mediators come in
Exogenous stimuli of inflammation
- microbes
- foreign bodies (plant material, suture material)
- injury (chemical, thermal, heat, ischemia)
Endogenous stimuli of inflammation
Autoreactive: newly developed antigens from degenerate or neoplastic cells
- hypersensitivity rxns
- activation of innate response
Innate immune response
Nonspecific defense
- physical barriers
- molecular products (secreted by epithelial cells)
- chemical mediators from effector cells within CT of the barriers (preformed and synthesized from mast cells, leukocytes, macrophages)
Characteristics of acute inflammation
- recognition of injury/pathogen
- send inflammatory cells
- send effector molecules
- repair and heal (reparative phase)
Fluidic versus cellular phase
- fluidic phase: microvascular exudation of electrolytes, fluid and plasma proteins (dilution)
- cellular phase: leukocyte emigration (killing)
How does the body recognize invaders, damaged cells, or foreign material?
- cellular receptors
- cellular sensors
- circulating proteins
Where are receptors located on innate immune cells?
- plasma membrane (ex: TLRs, extracellular microbes)
- cytosolic receptors (NOD-like, RIG-like, intracellular microbes)
- endosome receptors (TLR, ingested microbes)
Toll-like receptors
Numerous TLRs, each recognizes a different set of microbial molecules
- induction of pro-inflammatory cytokines and type 1 interferons
TLR4
Recognizes:
- LPS
- taxol
- F protein
- hsp60
- fibronectin
TLR2
Recognizes:
- LPS
- PGN
- zymosan
- GPI anchor
TLR5
Recognizes:
- flagellin
TLR9
Recognizes:
- CpG DNA
What are the 2 types of pattern recognition receptors?
PAMPs: pathogen-associated molecular patterns –> microbial structures
DAMPs: danger-associated molecular patterns –> released from necrotic cells
