5. Chronic Inflammation Flashcards
What are the causes of chronic inflammation?
Persistant infection
Autoimmune
Prolonged exposure to toxic agents
Unknown aetiology
What are the morphological features of chronic inflammation?
Infiltration of mononuclear cells
Tissue destruction
Attempts at healing (angiogenesis and fibrosis)
What is the most important cell in chronic inflammation?
Macrophages
What are the functions of macrophages in chronic inflammation?
Secrete cytokines and growth factors
Phagocytosis
Activates T lymphocytes
What activates macrophages?
Cytokines and endotoxins
What type of inflammation depends on B and T lymphocytes?
Granulomatous
What are macrophages in the liver known as?
Kupffer cells
What are macrophages in the spleen and lymphatics known as?
Sinus histiocytes
What are macrophages in the CNS known as?
Microglia
What is contained in the granules of eosinophils?
Major Basic Protein: toxic to parasites
What is granulomatous inflammation also known as?
Type 4 hypersensitivity reaction
What is a granuloma?
Accumulation of epitheloid macrophages surrounded by lymphocytes
Why are macrophages called epitheloid in granulomatous inflammation?
High cytoplasm
What is the name given to several epitheloid macrophages fused together?
Giant cell
What circumstances cause the formation of a granuloma?
In response to substances that resist lysosomal degradation or induce T cell hypersensitivity
ie. foreign materials and certain micro-organisms
What do macrophages present to MHC-II receptors on T cells in a type 4 delayed hypersensitivity reaction?
Ags
What type of giant cells are found in type 4 delayed hypersensitivity reaction?
Langhans type giant cells
Nuclei in a U-shape in periphery
What are 3 features of sarcoidosis?
Non-caseating naked granuloma
Schaumann bodies
Asteroid bodies
What is serous inflammation?
Accumulation of thin fluid from secretion of mesothelium or serum
What is fibrinous inflammation?
Accumulation of fluid and fibrin
What is suppurative inflammation?
Large amounts of pus produced
May lead to abscess formation
What is an ulcer?
Local defect in epithelial surface due to shedding
What is an acute ulcer?
Loss of full epithelium thickness
May or may not involve scarring
What is a chronic ulcer?
Deep penetration
Always scarring
What is a sinus?
Tract lined by granulation tissue from a chronically inflamed cavity to the surface
What is a fistula?
Abnormal communication between 2 surfaces
Name 5 infectious causes of granulomatous inflammation
TB Leprosy Histoplasmosis Toxoplasmosis Syphilis
What name is given to substances that induce fever?
Pyrogens
How do bacterial products induce fever?
Stimulate leukocytes to release cytokines
Increases cyclooxygenase which increases prostaglandins
How do NSAIDs lower fever?
Inhibit prostaglandin production
Where are acute phase proteins produced?
Liver
Name 3 acute phase proteins
CRP
SAA
Fibrinogen
What is leukocytosis?
High leukocyte count in response to inflammation, including immature leukocytes
What other response to inflammation are there?
Increase HR and BP Decrease sweating Shivering Anorexia and malaise Severe sepsis
How is granuloma formation different in a defective immune system?
Transformation of macrophages to epitheloid cells is not effective, appear as foamy cells
What does a Langhan’s giant cell look like?
Giant cell with 20+ nuclei arranged in a U shape
