Chronic Inflammation Flashcards
Outcomes of acute inflammation, chronic inflammation, wound healing and repair
What are the four outcomes of acute inflammation?
- Complete resolution
- Suppuration/abscess formation
- Healing by fibrosis/organization
- Chronic inflammation
Define chronic inflammation
Inflammation lasting weeks or months in which active inflammation, tissue destruction, and attempts at healing are proceeding simultaneously
Can chronic inflammation arise without a pre-existing acute inflammatory component?
Yes
What are three examples of chronic inflammation that occur without a pre-existing acute inflammatory component?
- Persistent microbial infection
- Prolonged exposure to exogenous or endogenous toxic agents
- Autoimmune diseases
Within the context of chronic inflammation, macrophages change leading to…
- Long-lived tissue macrophages
- Epithelioid cells
- Multinucleated giant cells
What is the predominant cell in granulomatous inflammation?
The activated macrophage (possesses a modified epithelial-like (epithelioid) appearance)
What are four features of granulomatous inflammation?
- Multinucleated giant cells
- Lymphocytes
- Necrosis
- Fibroblasts
What is a granuloma?
A focal area of granulomatous inflammation; a central zone of necrosis surrounded by microscopic aggregates of epithelioid cells, lymphocytes, and fibroblasts
What are some general causes of granuloma?
- Immune reaction
- Chronic irritation
- Undigestible foreign material
- Unknown etiologies
What are some specific causes of granuloma?
- Tuberculosis
- Leprosy
- Syphilis
- Sarcoidosis
- Fungal infection
- Suture
What are four morphologic patterns in acute and chronic inflammation?
- Serous inflammation
- Fibrinous inflammation
- Suppurative inflammation
- Ulceration; decubitus ulcers
Repair process involves:
- Total reconstruction (regeneration/resolution)
- Partial reconstruction
- Universal repair tissue: fibrous connective tissue scar
What are the four components of wound healing and repair?
- Angiogenesis: migration and proliferation of endothelial cells
- Migration and proliferation of fibroblasts
- Deposition of extracellular matrix
- Remodeling of connective tissue
What is the hallmark tissue of early healing by fibrosis?
Granulation tissue
Granulation tissue is composed of what four components?
- Proliferating small capillaries
- Proliferating fibroblasts/myofibroblasts
- Extracellular fluid
- Macrophages
What are the four functions of granulation tissue?
- Fill in tissue “gaps”
- Remove dead cell debris
- Aid in wound contraction
- Form an early “pre-scar”
What are the steps of healing by primary union/intention in order?
- Blood clot fills incisional space
- Neutrophil infiltration
- Epithelial continuity restored
- Macrophage infiltration
- Granulation tissue fills space
- Progressive collagenization
- Remodeling
What is secondary union/intention compared to primary intention?
- Large amounts of granulation tissue are required
- Inflammatory reaction is more prolonged
- More debris and inflammatory exudate
- More pronounced scar formation
What factors influence local wound healing?
- Type, size, and location
- Vascular supply
- Infection
- Movement
What factors influence systemic wound healing?
- Circulatory status
- Infection
- Malnutrition
complications of normal wound healing
What is proud flesh?
Excessive granulation tissue
complications of normal wound healing
What is keloid formation?
Hypertrophic scar: excessive collagen deposition
complications of normal wound healing
What is wound dehiscence?
Mechanical stress
complications of normal wound healing
What is contracture?
Excessive wound contraction