MoD Session 3- Chronic Inflammation Flashcards
What is fibrosis?
Thickening and scarring of connective tissue in response to injury.
What is chronic inflammation?
It is a response to injury with associated fibrosis.
What are the three ways in which chronic inflammation can arise?
- takes over from acute inflammation - if the damage is too severe to be resolved.
- de novo- occurs in some autoimmune conditions, chronic infections, is due to low level chronic irritation.
- alongside AI- in sever, persistent, repeated irritation.
Are chronic inflammation microscopic characteristics stereotyped?
No
What are macrophages?
Derivatives of monocytes that are found in tissue spaces.
What are the four functions of macrophages?
- phagocytosis
- presentation of antigens to the immune system to induce an immune response
- synthesis of: complement components, cytokines, clotting factors and proteases
- control of other cells by cytokine release.
What are the two functions of lymphocytes?
B lymphocytes produce antibodies
T lymphocytes are involved in control and cytotoxic functions
Where are eosinophils present? (3)
Allergic reactions
Parasite infections
Some tumours
What do fibroblasts/myofibroblasts do?
They are recruited by macrophages and produce collagen
What are giant cells?
They are multinucleate cells made by the fusion of activated macrophages during frustrated phagocytosis.
What are the three types of giant cell and when are they seen?
- Langhans- TB
- foreign body- when foreign material is present
- Touton- seen in fat necrosis/ where there is a lesion with high lipid content.
What are the four effects of CI?
- fibrosis- excessive fibrous tissue due to cytokines stimulating fibroblasts to produce more collagen
- impaired function
- inappropriate immune response- can attack normal tissue
- atrophy
What is granulomatous inflammation?
Inflammation with the prescence of granulomas!
What are granulomas?
Aggregates of activated macrophages that form when the immune system walls off someone it can’t eliminate.
What are the 3 causes of granulomatous inflammation?
- infections
- foreign material
- unknown- e.g sarcoidosis, Crohn’s, wegners granulomatous