Session 3 Flashcards
(61 cards)
What is chronic inflammation?
Chronic response to injury with associated fibrosis
In what three ways can chronic inflammation develop?
May ‘take over’ from acute inflammation if damage too severe to be resolved within a few days, may arise ‘de novo’, or may develop alongside acute inflammation in severe persistent/repeated irritation
What are the most important characteristic in chronic inflammation?
The type of cells present (chronic inflammation is much more heterogeneous than acute inflammation)
What cells are found in chronic inflammation?
Macrophages (derived from blood monocytes), lymphocytes, eosinophils, fibroblasts/myofibroblasts
What are macrophages derived from?
Blood monocytes
Describe the histological appearance of macrophages (blood monocytes)
Large, folded nucleus; grey/blue granular cytoplasm
Describe the difference in phagocytosis between macrophages and neutrophils
Macrophages are better with dead tissue, polymorphs are better with bacteria
What are the functions of macrophages?
Phagocytosis, antigen presentation, synthesis of cytokines, complement components, blood clotting factors and proteases (signalling), and the control of other cells by this cytokine release
What are the functions of lymphocytes?
Complex, mainly immunological; B cells produce antibodies (plasma cells), T cells are involved in the control of the immune action, and some cytotoxic actions. The presence of lymphocytes is not necessarily indicative of inflammation
How long does plasma cell appearance usually take in an immune reaction?
Around a week
What is the appearance of plasma cells likened to?
A clock-face
What situations are eosinophils commonly found in?
Allergic reactions, parasite infections, some tumours
What are the predominant cells in rheumatoid arthritis?
Plasma cells
What are the predominant cells in chronic gastritis?
Lymphocytes
What are the predominant cells in leishmaniasis (a protozoal infection)?
Macrophages
What are giant cells? What is the commonest theory for their formation?
Multinucleate cell made by the fusion of macrophages; frustrated phagocytosis
What are the three types of giant cells commonly seen?
Langhans, foreign body type, Touton
What are Langhans giant cells commonly seen in? Describe their structure
Tuberculosis (can be seen in other diseases); usually a horseshoe shaped nuclei arrangement, around granular cytoplasm
What is the function of foreign body type giant cells?
Prevent spread by localisation of foreign body
What situation are Touton giant cells commonly seen in?
Fat necrosis; the gat like foam is due to the emptiness of the cells
What are the four principle effects of chronic inflammation?
Fibrosis, impaired function (rarely increased), atrophy, stimulation of immune response
What is chronic cholecystitis?
Inflammation of gall bladder most commonly due to gallstone in cystic duct; the acute inflammatory response causes the gallstone to pop out, the gallstone blocks the duct again and the process continues
Why does chronic inflammation occur in cholecystitis?
The repeated acute inflammatory response results in chronic inflammation
Why does the wall of the gallbladder appear white in colour in cholecytitis? What is the normal colour?
Translucent; chronic inflammation results in formation of fibrous tissue
