Tutorial 1
Inflammation and cellular responses
Inflammation
• Is a protective response
• The body’s response to injury
• Interwoven with the repair process
Inflammation
• Types– Acute (sec, mins, hrs)– Chronic (days, weeks, months, yrs)
Causes of inflammation
• Bacterial• Viral• Protozoal• Metazoal• Fungal• Immunological• Tumours• Chemicals, toxins etc• Radiation
Acute inflammation
Inflammation
• The Cardinal Signs of Acute Inflammation
RUBOR
CALOR
TUMOR
FUNCTIO LAESA
Cardinal signs of inflammation
Cardinal signs of inflammation
Cardinal signs of inflammation
Cardinal signs of inflammation
Cardinal signs of inflammation
Cardinal signs of inflammation
Inflammation
The basis of the five cardinal signs
• Increased blood flow due to vascular dilatation gives redness and heat.
• Increased vascular permeability gives oedema causing tissue swelling.
• Certain chemical mediators stimulate sensory nerve endings giving pain. Nerves also stimulated by stretching from oedema.
• Pain and swelling result in loss of function.
The process of inflammation
Components of acute and chronic inflammation
Local manifestations of acute inflammation
Leukocyte migration in inflammation
Molecules modulating endothelial-neutrophil interactions
Chemical mediators of inflammation(local and systemic)
The complement system
Arachidonic acid metabolites
HETE = hydroxyeicosatetraenoic acidHPETE = hydroperoxyeicosatetraenoic acid
Cytokines (IL-1 and TNF)
Nitric oxide (NO)
Effects of inflammation and their major mediators
Vasodilation:Prostaglandins, NO
Increased vascular permeability:Histamine, serotonin, C3a, C5a, bradykinin,
Leukotrienes C4, D4, E4, platelet activating factor
Chemotaxis, leukocyte activation:C5a, lekotriene B4, bacterial products, chemokines (IL-8)
Fever:IL-1, IL-6, TNF, prostaglandins
Pain:Prostaglandins, bradykinin
Tissue damage:Neutrophil and macrophage lysosomal enzymes, oxygen metabolites
NO
Chronic inflammation
Cells of the chronic inflammatory response
• Lymphocytes
• Monocytes/ macrophages
• Plasma cells
Maturation of circulating monocytes to macrophages
Macrophage-lymphocyte interactions in chronic inflammation
Granulomatous inflammation
Bacterial:TB, Leprosy, Syphillis, cat-scratch disease
Parasitic:Schistosomiasis
Fungal:Histoplasma, blastomycosis, cryptococcus
Inorganics, metals, dusts:Silicosis, berrylliosis
Foreign body
Unknown:Sarcoidosis
Granulomatous inflammation: tissue effects
Healing and repair
The major components of the extracellular matrix (ECM) required for
healing and repair
Major growth factors in wound healing
Critical steps in angiogenesis
Wound healing: critical steps
Outcome of healing and repair