Inflammation & Repair
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Transcript of Inflammation & Repair
Inflammation & Repair
Chronic Inflammation
Chronic Inflammation
Cell Types in Chronic Inflammation
• Macrophages• Types of Macrophages (fixed)
– Kupffer cells - liver– Pulmonary alveolar macrophages– Histiocytes - connective tissue– Microglia - brain– Osteoclasts - bone– Spleen/lymph nodes– Langerhans cells - epidermis
Other Cell Types• Lymphocytes• Plasma cells• Eosinophils
– IgE mediated, parasitic infections• Mast Cells
Granulomatous Inflammation
• Granulomatous inflammation– focal accumulations of activated macrophages
with an epithelial-like (epithelioid) appearance. • Granuloma
– microscopic aggregation of epitheliod macrophages surrounded by a collar of lymphocytes and occasionally plasma cells.
Granulomatous Inflammation - TB
Granulomatous Inflammation - TB
Granulomatous Inflammation - TB
Granulomatous Inflammation - TB
Granulomatous Inflammation - TB
Healing and Repair
Cell Types with Different Regenerative Capacities
Resolution vs Repair
Granulation Tissue
• Proliferation of new blood vessels and fibroblasts
• Fibroblasts myofibroblasts
Granulation Tissue
Granulation Tissue
Wound Healing
• Primary union (healing by 1st intention) – healing of a clean surgical incision– very little tissue damage is present
• Secondary union (healing by 2nd intention)– healing of a large tissue defect
Healing by First Intention Healing by Second Intention
24 Hours
Healing by First Intention Healing by Second Intention
3 to 7 Days
Healing by First Intention Healing by Second Intention
Weeks
Aberrations of Wound Healing
• Inadequate granulation tissue/healing• Excessive repair
– Hypertrophic scar– Keloid
• Contractures
Hypertrophic Scar
Keloid
Conditions Inhibiting/Delaying Wound Healing
• Poor local vascular supply– Poor oxygenation, decreased bacterial
resistance, low temperature, and an acid pH• Deficiencies of vitamin C, protein, zinc• Infection• Tissue necrosis
– Foreign material delay healing and acts as a nidus for bacterial infection
• Excessive movement
Extracellular Matrix- Collagen -
• Tropocollagen is the basic unit• Intracellular
– procollagen• Extracellular
– procollagen cleavage & lysine oxidation cross-linking
– tensile strength
Wound Healing
• Replacement of Type III collagen by Type I in wound healing will have a maximal tensile strength of 70-80% of normal (takes about 3 months)
Outcomes of Acute Inflammation
The End
Chronic Inflammation&
Repair