Chronic Inflammation Flashcards
Which of the 4 clinical signs of acute inflammation persist in chronic inflammation?
- Swelling and pain persist
- Redness and heat resolve
What is the dominant cell type involved in chronic inflammation?
Macrophages
Define chronic inflammation
Chronic response to injury with associated fibrosis
What are the 3 situations in which chronic inflammation can arise?
- When it takes over from acute inflammation (most common)
- Begins without preceding acute inflammation e.g TB, RA, prolonged expose to toxic agents e.g silica
- Develops alongside acute inflammation e.g ongoing bacterial infection
What does chronic inflammation look like under the microscope?
macrophages and lymphocytes predominant cell type (granulation tissue)
What are macrophages called when they are circulating in blood?
Monocytes
Give some of the functions of macrophages?
- Phagocytosis
- Secretion of substances that activate other cells
- Present antigens to immune system to initiate immune response
- Stimulate angiogenesis
- Induce fibrosis
- Induce fever, acute phase reaction and cachexia
What are the functions of T and B lymphocytes?
- process antigens
- secrete antibodies (B cells differentiated to plasma cells)
- secrete cytokines (T cells)
- kill cells (NK cells attack virally infected cells)
What is the function of Eosinophils?
Attack large parasite (worms) and present in allergic reactions
How do Eosinophils look under the microscope?
tomato with sunglasses
What is the function of fibroblasts and myofibroblasts?
- recruited by macrophages
- make collagen, elastin and glycosaminoglycans
What are giant cells?
Multinucleated cells made by fusion of macrophages when certain bacteria are present
Name the 3 types of giant cell and describe the circumstances you would see them in
- Langerhans cell- seen mainly in TB
- Foreign body giant cells- when a foreign body is hard to digest
- Touton cell- seen in fat necrosis
Describe the appearance of Langerhan cells
Nuclei line up around the edge of the cell in a horse-shoe/ semi-circle
Describe the appearance of foreign body giant cells
Nuclei arranged randomly in the cell