Wound Healing

Regeneration and scar formation

What are the key processing in repair of a wound

Macrophages

What cell plays a central role in repair

Primary and secondary intention

What are the types of wound healing

Clean, closed wound edges due to surgery or paper cut, promotes regeneration

What is primary intention

Larger open wound due to extractions or burns, results in granulation tissue and scarring

What is secondary intention

Injured tissue Cells , vascular endothelial cells and fibroblasts

What cell are important in regeneration

Neutrophils phagocytosis necrotic tissue and foreign substances

What happens on day 1 of the repair sequence

Macrophages migrate to site and granulation tissue starts to form, covered in a fibrin clot

What happens on day 2 of repair sequence

Lymphocytes and plasma cells migrate to site

What happens on day 3-6 of the repair sequence

Clot is digested and inital repair is complete

What happens on day 7 of the repair sequence

Fibroblasts mature and scar tissue form

What happens on day 14 of the repair sequence

Composed of capillaries and immature fibroblasts

What is granulation tissue

If injury is in tissue that cant regenerate or there is major damage to the extracellular matrix

When/why does scar formation

vascular endothelial growth factor (VEGF)

What initiates the formation of new blood vessels during repair of an injury

Fibroblast growth factor (FGF)

What initiates the migration of fibroblasts to the injury site during repair

Macrophages

What cells make fibroblast growth factor

Red/pink granular tissue

What does granulation tissue look like

3-5 days after injury

When does granular tissue appear.

TGF-beta

What initiates fibroblasts to deposit collagen

Stimulates production and inhibits breakdown of extracellular matrix proteins and is anti inflammatory

What is the function of TGF-beta

Migration of fibroblast and smooth muscle cells

What is the function of PDGF

Fibroblast migration

What is the function of FGF

Stimulates collagen synthesis and fibroblast migration

What is the function of IL-13

Excessive formation of collagen during the repair process

What is a keloid

Matrix metalloproteinase (MMPs)

What is use to remodel connective tissue over time

Degrade extracellular matrix proteins

What is the function of matrix metalloproteinase

Proteases

What activates matrix metalloprotienases

Tissue inhibitors of metalloproteinases (TIMPs)

What inhibits matrix metalloproteinases