Chronic inflammation Flashcards
Chronic inflammation is the simultaneous occurrence of what 3 things?
Active inflammation
Tissue destruction
Attempts at repair
What cells are involved with active inflammation during chronic inflammation?
Mononuclear cell filtration - macrophages, lymphocytes, plasma cells
What happens during chronic inflammation attempts to repair?
Fibrosis
Connective tissue replaces damaged tissue
Angiogenesis
When might chronic inflammation occur?
Persistent infections
Prolonged irritation not resolved by acute inflammation
Cellular immune response
What is mononuclear infiltration (part of active inflammation)?
Recruitment of monocytes and macrophages
What are the roles of macrophages in chronic inflammation?
Phagocytosis Antigen presentation Secreting proinflammatories and enzymes Wound healing Regulation of WBC pools
What is cells do lymphocytes interact with in chronic inflammation?
Macrophages
What do plasma cells (differentiated B cells) produce?
Antibodies
What are Mott cells?
Plasma cells containing Russell’s bodies (golgi filled with antibodies)
Chronic parasitic inflammation also sees the recruitment of which cells?
Mast cells
Eosinophils
Are neutrophils present in chronic inflammation?
First response
Chronic suppurative inflammation only
What is the difference between neutrophils and macrophages in terms of cell division?
Neutrophils - incapable of dividing
Macrophages - undergo mitosis
What is the difference between neutrophils and macrophages in terms of differentiating at the injury site?
Neutrophils - terminally differentiated on injury site arrival
Macrophages - differentiate when activate by inflammatory stimuli
Neutrophils are capable of chemotaxis, phagocytosis, extravasation and degranulation. Macrophages are also capable of this, however what else do they cause?
Fever
Leukocytosis
Acute phase response
Chronic inflammation includes attempts at healing. How does it aim to restore anatomy and function?
Replace damaged tissue with healthy tissue - regeneration and repair
What are labile cells?
Continuously dividing cells due to population of stem cells e.g. epidermis
What are stable cells?
Quiescent - dormant. Low level of replication but proliferate in response to injury e.g. hepatocytes
What are permanent cells?
Non-dividing cells, cannot undergo mitosis
E.g. cardiomyocytes
What is fibrosis?
Deposition of collagen fibres to replace lost tissue
NOT same as fibrin!
What are the 4 stages of fibrosis?
Angiogenesis (neovascularsiation)
Migration and proliferation of fibroblasts
ECM deposition - scar formation
Remodelling of fibrous tissue - replace granulous tissue with scar
What is chronic proliferative inflammation?
Formulation of granulation tissue
What is abscess formation?
Due to chronic or acute
Suppurative inflammation
What is within each of the 3 layers of abscesses?
Outer layer - old granulation tissue, few cells
Middle - young granulation tissue, some cells
Inner - purulent exudate
How do abscesses form?
Necrosis of tissue
Emigration of neutrophils
Phagocytosis and necrosis
What are abscesses composed of?
Abscess membranes
Liquefaction
What are ulcers? What causes them?
Damage to epithelial cells on tissue surface
Sloughing off of necrotic cells
Where are ulcers mainly seen?
GI tract
Urogenital tract
Skin
What happens in the chronic stage of ulceration?
Wall formation and scarring
What is granulomatous inflammation?
Macrophage dominated chronic inflammation
What is a granuloma?
Focal area of granulomatous inflammation
What is granulation tissue?
Growth of new blood vessels (angiogenesis) into deposited fibrin during repair
Which cells are granulocytes?
Neutrophils
Eosinophils
