Chronic Inflammation 2 Flashcards
What is granulomatous inflammation characterised by?
presence of granulomas in tissues and organ
What is granulomatous tissue stimulated by?
indigestible antigen that the body cannot get rid of
What does granulomatous inflammation cause?
many serious infections and idiopathic diseases
What are granulomas?
- aggregates of epithelioid macrophages in tissues
- may contain giant cells
- may surround dead material
- may be surrounded by lymphocytes
- contain neutrophils, eosinophils
- response to indigestible antigen
- many are type IV hypersensitivity reactions
What are giant cells?
- the fusion of macrophages to form larger cells
- large cytoplasm: multiple nuclei
What are Langhans type cells?
- classically found in TB
- peripheral rim of nuclei
- large eosinophilic cytoplasm
Describe foreign bodies in granulomatous tissue?
- often associated with pyogenic granulation tissue
- acutely inflamed
- neutrophils, pus
- organisation
- giant cells
What can vacuoles containing silicone arise from?
ruptured silicone implants
When are Warthin-Finkeldy rarely seen?
in measles
What are 3 examples of granulomatous diseases?
- Tuberculosis
- Leprosy
- Syphilis
What is caseous necrosis?
dead tissue surrounded by macrophages, giant cells, lymphocytes
What drug combination kills the pathogen that causes leprosy?
- dapson
- rifampicin
- clofazimine
What are 3 examples of condition that involve non-infective granulomas?
- rheumatoid disease
- sarcoidosis
- Crohn’s disease
Describe the basic mechanism of wound healing?
- phase of acute inflammation
- granulations tissue formation
- local angiogenesis
- fibrosis and scar formation
Describe surgical wound healing?
- healing by primary intention
- minimal gap-blood clot forms
- small amount of granulation tissue
- small linear scar
Describe healing of larger defects?
- healing by secondary intention
- lots of granulation tissue ingrowth
- contraction and scarring
What is the sequence of events from wound to repair?
- injury, blood clot, acute inflammation, fibrin
- many growth factors and cytokines involved
- granulation tissue growth- angiogenesis
- phagocytosis of fibrin
- myofibroblasts move in and lay down collagen
- contraction of scar
- re-epithelialisation
What improves wound healing?
- cleanliness
- apposition of edges
- sound nutrition
- metabolic stability and normality
- normal inflammatory and coagulation mechanisms
- local mediator involvement
What impairs wound healing?
- dirty,gaping wound with large hematoma
- poorly nourished, lack of vitamin C,A
- abnormal CHO metabolism, diabetes, corticosteroid therapy
- inhibition of angiogenesis
How does fracture healing differ from wound healing?
It is a modified situation in bone as there has to be repair of bony structure as well as soft tissue
Describe the sequence of events in fracture healing?
- trauma, fracture, hematoma
- bits of dead bone and soft tissue
- acute inflammation, organisation, granulation tissue, macrophages remove debris
- granulation tissue contains osteoblasts as well as fibroblasts
Describe callus formation.
- osteoblasts lay down woven bone
- nodules of cartilage present
- followed by bone remodelling
What does bone remodelling involve?
- osteoclasts remove dead bone
- progressive replacement of woven bone by lamellar bone
- reformation of cortical and trabecular bone
What stimulates proliferation in angiogenesis?
VEGF released by hypoxic cells
What does angiogenesis and organisation in thrombosis do?
- limits thrombus propagation
- reinstatement of flow
What role does angiogenesis play in malignant tumours?
- angiogenesis occurs as tumour grows
- potential for therapeutic control
What role does fibrosis and scarring play in atherosclerosis?
-similarities with chronic inflammation
