Chronic Inflammation, Repair and Regeneration (week 1) Flashcards
Which types of immunity are involved in acute and chronic inflammation?
acute: innate
chronic: innate + adaptive
What are the main events of chronic inflammation?
Angiogenesis
Fibrosis
Which cells are involved in acute and chronic inflammation?
acute: neutophils, mast cells, macrophages
chronic: macrophages, lymphocytes, plasma cells
What are the clinical signs of chronic inflammation?
Amyloidosis
Cachexia
Anaemia
Under what circumstances does chronic inflammation arise?
Progression from acute / recurrent episodes of acute
Persistant infection
Prolonged exposure to toxic agents
Autoimmunity
What is angiogenesis and why does it occur?
Generation of new blood vessels, allows more inflammatory cells to reach the infected area
How is a granuloma defined?
Collection of activated epithelioid macrophages (epithelioid as they resemble epithelial cells with pink cytoplasm, indistinguishable membrane and oval nuclei)
Surrounded by mononuclear leukocytes
Caeseating or non-caseating
May also contain multinucleate giant cells: many macrophages fused together
What causes granulomatous inflammation?
TB Schistosomiasis Cryptococcus Silicosis Sutures Sarcoidosis Ulcerative colitis
What is the difference between regeneration and repair?
Regeneration: Damaged cells replaced by identical tissue, reinstitution of specialised function
Repair: Damaged cells cannot be replaced by identical tissue - leads to fibrosis and scarring
What are labile cells?
Have high normal turnover, continuously move around cell cycle.
Active stem cell population
Excellent regenerative capacity
e.g. epithelial cells
What are stable cells?
Low physiological turonver, but can rapidly increase turonover if required.
Good regenerative capacity
e.g. liver and renal cells
What are permanent cells?
No physiological turonover, cannot re-enter cell cycle
Long life cells
No regenerative capacity
e.g. neurons, muscle cells
Which cell populations have stem cells?
labile and stable
What is healing by first intention?
Healing of a clean, unifected surgical wound with apposed edges and good haemostasis
How does healing by second intention differ from first?
more granulation tissue formed
more wound contraction
