Chronic Inflammation 2 Flashcards
What is granulomatous inflammation characterised by?
Presence of granulomas in tissues and organs
What is granulomatous inflammation stimulated by?
Indigestable antigen
What can the cause of granulomatous inflammation be described as?
Idiopathic (no known cause)
What does idiopathic mean?
No known cause
What are granulomas composed of?
Aggregates of epitheloid macrophages in tissue
May contain giant cells
May be surrounded by lymphocytes
Contains neutrophils and eosinophils
What may granulomas surround?
Dead tissue
What are granulomas the response to?
Indigestable antigen
What kinds of hypersensitive reaction are many granulomas?
Type IV
What are giant cells?
Fusion of macrophages to form larger cells (larger cytoplasms and multinucleated)
What are different kinds of granulomas?
Langans type
Foreign body type
Silicone associated
Warthin-Finkeldy type
Where are Langhans type granulomas commonly found?
In tuberculosis
What are properties of Langhams type granulomas?
Peripheral rim of nuclei
Large eosinophillic cytoplasm
What do foreign body type granulomas contain?
Neutrophils
Pus
Giant cells
How are the nuclei arranged in foreign body type granulomas?
Scattered around the cytoplasm
What are silicone associated granulomas due to?
Rupture of silicone implants, vacouls contain leaked silicone
Where are Wartin-Finkeldy type granulomas found?
Measles
How are the nuclei arranged in Warthin-Finkeldy granuloma?
Clustered in the centre
What are examples of infectious granulomatous diseases?
Tuberculosis (mycobacterium tuberculosis)
Leprosy (mycrobacteria leprae)
Syphilis (treponema pallidum)
What is tuberculosis caused by?
Mycobacterium tuberculosis
What is leprosy caused by?
Mycobacterium leprae
What is syphilis caused by?
Treponema pallidum
What are examples of non-infective granulomas?
Rheumatoid disease (tissue specific autoimmune disease, targets synovial fluid in joints)
Sarcoidosis
Crohn’s disease (chronic inflammatory bowel disease)
What is Rheumatoid disease?
Tissue specific autoimmune disease, targets synovial fluid in joints
What is Crohn’s disease?
Chronic inflammatory bowel disease
What is the process of wound healing?
1) Phase of acute inflammation
2) Granulation tissue formation
3) Local angiogenesis (new vessels grow)
4) Fibrosis and scar formation
What does ideal surgical wound healing involve?
Healing by primary intention
Minimal gap
Small amount of granulation tissue
Small linear scar
What does healing of larger defects lead to?
Healing by secondary intention
Lots of granulation tissue ingrowth
Contraction and scarring
What is the detailed process of healing?
1) Injury, blood clot, acute inflammation, fibrin formation
2) Many growth factors and cytokines involved
3) Granulation tissue growth - angiogenesis
4) Phagocytosis of fibrin
5) Mycofibroblasts move in and lay down collagen
6) Contraction of scar
7) Re-epithelialisation
What are factors that help wound healing?
Cleanliness
Apposition of edges (no haemotoma)
Sound nutrition
Metabolic stability and normality
Normal inflammatory and coagulation mechanisms
Local mediators
What are things that would impair wound healing?
Dirty, gaping wound, large haematoma
Poorly nourished, lack of vitamines A and C
Abnormal metabolism, diabetes
Inhibition of angiogenesis
How does fracture healing compare to regular tissue healing?
Similar except the addition of repairing bony structures
What are the sequence of events for healing a fracture?
1) Trauma, fracture, haematoma
2) Bits of dead bone and soft tissue
3) Acute inflammation, organisation, granulation tissue, macrophages remove debris
4) Granulation tissue contains osteoblasts as well as fibroblasts
What does the granulation tissue of a healing fracture contain?
Osteoblasts
Fibroblasts
What is a haematoma?
Solid swelling of clotted blood within tissues
What is formed during fracture repairing?
A callus
What is the process of a callus being formed in fracture healing?
1) Osteoblasts lay down woven bone
2) Nodules of cartilage are present
3) Followed by bone remodelling where osteoclasts remove dead bone, progressive replacement of woven bone by lamellar bone and reformation of cortical and trabecular bone
What happens during the bone remodelling when a callus is formed while healing a fracture?
1) Osteoclasts remove dead bone
2) Progressive replacement of woven bone by lamellar bone
3) Reformation of cortical and trabecular bone
What is angiogenesis?
Formation of new blood vessels
What is the process of angiogenesis?
1) Vascular endothelial growth factor (VEGF) release by hypoxic cells stimulation proliferation
2) Enzyme secretion aids process
3) New vessels form
4) Enable blood supply to enter damaged tissue
How does the purpose of angiogenesis differ?
It differs in different situations such as:
Thrombosis
Malignant tumours
Fibrosis and scarring in athlerosclerosis
What is the purpose of angiogenesis in thrombosis?
Limits thrombus propagation
Reinstatement of flow
What is the purpose of angiogenesis in malignant tumours?
Potential for therapeutic control
In malignant tumours what does angiogenesis occur in?
Tumour growth
What is the purpose of angiogenesis in fibrosis and scarring in athlerosclerosis?
Similar to chronic inflammation
