Flashcards in Chronic Inflammation Deck (24)
What is chronic inflammation?
- where cell population is mostly lymphocytes/plasma cells/macrophages
- which causes tissue/organ damage
- is a long term, insidious process
- which is characterised by granulation and scar tissue
What are the main causes of chronic inflammation?
- resistance on infection to phagoctytosis/intracellular killing e.g. TB/leprosy
- endogenous factors e.g. necrotic tissue/bone
(cannot easily be phagocytosed and can become stuck)
- exogenous tissue e.g. prostheses/sutures
- autoimmune diseases e.g. thyroiditis/rheumatoid arthritis
What are the main clinical appearances of chronic inflammation?
- granulomatous inflammation
- cellular infiltrate of lymphocytes/macrophages
* vague symptoms - malaise/weight loss etc.
Describe the process of granulation
- capillaries grow into the inflammatory mass
- plasma proteins/macrophages gain access
- fibroblasts lay down collagen to repair damage and replace exudate
- patches and pulls cells together
- replaces necrotic tissue
What are the possible outcomes of chronic inflammation?
- ongoing damage
- loss of function
How may acute inflammation give rise to chronic inflammation?
- large volume of damage
- inability to remove debris
- failure to resolve itself
How can fibrosis be problematic?
When it adheres loops of the bowl together after peritonitis (inflammation of the peritoneum), the bowl cannot contract as it is made inelastic by the volume of scar tissue it contains
What is a fibroblast?
Metabolically active motive cell that makes and assembles structural proteins
What is granulomatous inflammation?
- type of chronic inflammatory response
- stimulated by indigestible antigens
- characterised by granuloma presence in tissues/organs
What is a granuloma?
- gathering of macrophage
- contain giant cells
- surround areas of dead tissue
- be surrounded by lymphocytes
contain neutrophils and eosinophils
Name an example of an infective granulomatous inflammatory condition
Name an example of a non-infective granulomatous inflammatory condition
What are Giant cells?
- masses formed by unions of macrophages
- multinucleate cells with a large cytoplasm
Name four types of giant cells
Foreign body type
What is a caseous necrosis?
- white lumps of dead tissue in the lungs caused by TB
- surrounded by giant cells/macrophages/lymphocytes
Describe the process of surgical wound healing
- primary intention
- minimal gap = small blood clot
- small amount of granulation tissue
- small linear scar
Describe the process of larger defect healing
- secondary intention
- lots of granulation tissue
- contraction/puckering and scarring
Describe the healing process (8 steps)
- blood clots (fibrin)
- acute inflammation
- granulation tissue formation
- angiogenesis (+ osteoblasts in fracture healing)
- fibrin phagocytosis
- fibrin replacement with collagen by myofibroblasts
- scar contraction and re-epithelialisation
How is the healing process improved?
- sound nutrition
- metabolic normality
- normal inflammation and coagulation
How is the healing process impaired?
- dirty/gaping/large haematoma
- poor nutrition
- lack of vitamin A/C
- abnormal metabolism (e.g. diabetes)
- angiogenesis inhibition
What is a callus?
bony healing tissue which forms around the ends of broken bones
Describe callus formation
- osteoblasts lay down woven bone
- cartilage nodes are present
- followed by bone remodelling
Describe the process of bone remodelling?
- removal of dead bone by osteoclasts
- replacement of woven bone with lamellar bone
- reformation of cortical and trabecular bone