chronic inflammation

Question 1

List the cell types involved in chronic inflammation.

Answer 1

LYMPHOCYTES

• B-cell differentiate into plasma cells which produce antibodies and memory cells
• T-cells: produce cytokines (attract,hold and activate macrophages, alter permeability) , interferons (have antiviral effects) and destroy antigens.

MACROPHAGES:
-monocyte-histiocyte-activated macrophage-epitheloid cell- giant cell
-antigen presenting cells which contain enzymes and interferons 
-removes debris 
FIBROBLAST
-motile cell
-metabolically active
-assembles structural proteins 

GRANULOMAS:

• may be made up of neutrophils and eosinophils , dead material
• may contain giant cell (large cytoplasm with many nuclei)
• may be surrounded by lymphocytes
• made up of macrophages
• response to undigested antigens
• Many are type 4 hypersensitivities

Question 2

List the major causes of chronic inflammation.

Answer 2

Acute phase: 
-granulation tissue
-does not resolve 
No acute phase:  
-Autoimmune disease 
-material resistant to digestion e.g. mycobacterium, cell wall resistant to enzyme activity
-exogenous substances e.g. sutures
-endogenous substances e.g. keratin, necrotic tissue

Question 3

Describe the adverse effects of tissue scarring.

-BONE

Answer 3

Fibrosis
chronic inflammation: 
1-blood clot-haematoma
2-acute inflammation
3-fibrin deposited
4-growth factors+ cytokines
5-granulation tissue
6-angioneogenesis- macrophages remove fibrin
7- fibrosis + formation of scar
8-contraction of scar
WITH BONE:
osteoblasts laid down alongside fibrin- lays down woven bone
cartilage nodules also present
osteoclasts remove dead bone
bone turnover replaces woven bone with spongy and compact bone

Question 4

List factors involved in promoting healing and repair.

Answer 4

Balanced nutrition
Angiogenesis
Active metabolism
Clean wound
Local mediators
Functional coagulation and inflammation process

Question 5

Define the role of angiogenesis in healing and repair.

Answer 5

Formation of new blood vessels.
Starts from capillary buds. Release of Vascular endothelial growth factors and enzyme secretion leads to formation of new vessels.
New vessels carry blood and nutrients to damaged tissue to aid repair.
In malignant tumours: grow around tumours allow metastasis. Can be used In therapeutic control.
In thrombosis: can be used to limit thrombus propagation.

Question 6

List the factors that impair healing and repair.

Answer 6

Dirt
Unstable metabolism
Unbalanced nutrition- lack of vitamin A and C
Inhibition of angioneogenesis
Large haematoma
Undefined margins-large wound 
Poor coagulation due to CHO diseases

Question 7

Giant cells

Answer 7

Have a large cytoplasm 
Multinucleate 
TYPES:
Langerhans:
- found in TB
-nuclei are peripherally arranged
-Large eisonophilic cytoplasm
Foreign body type:
-Associated with pyogenic granulation tissue (relating to Pus)
Silicone associated:
-Ruptured silicone implants
- vacuoles contain leaked silicone
Warthin-Finkeldy 
-central cluster of nuclei 
Important infections
-TB
-Leprosy
-Syphilis- Trepanoma pallidum

Question 8

What is healing by primary/ secondary intention?

Answer 8

Primary intention: When edges are proximal, wound is sterile e.g. surgical incision
Secondary intention: when wound edges cannot be approximated- not enough skin to cover the wound