Wound Healing Flashcards
What are the phases of wound healing?
- Inflammation
- Tissue formation
- Tissue remodelling
What is the function of platelets in wound healing?
- Facilitate haemostatic plug
- Secrete mediators of wound healing e.g. PDGF that activate and attract M0 and Fibroblasts
Are platelets essential to wound healing?
In the absence of haemorrhage, platelets are not essential to wound healing.
What is the role and fate of neutrophils in wound healing?
- cleanse wounded area of foreign particles and bacteria
- extruded with the eschar or phagocytosed by M0
Role of monocytes in wound healing?
Monocytes become activated M0:
- release GFs e.g. PDGF, VEGF ==> initiate formation of granulation tissue
- bind ECM proteins by integrin receptors ==> stimulates phagocytosis of microorganism and fragments of ECM
- secrete CSF1; TNFa; PDGF
How soon after injury does reepithelialisation occur?
Within hours of injury
What is the role of epidermal cells from skin appendages in wound healing?
- Epidermal cells from appendages remove clotted blood and damaged storm from wound space
- Undergo phenotypic alteration to enable cell movement.
When does granulation tissue appear?
New storm (granulation tissue) begins to invade wound space ~4/7 post injury
Role of M0 in formation of granulation tissue?
Provide continuing source of growth factors to stimulate fibroplasia and angiogenesis
Role of fibroblasts in formation of granulation tissue?
Produce new extracellular matrix to support cell ingrowth.
What is the provisional matrix?
Structural molecules of newly formed ECM; contribute to formation of granulation tissue by providing a scaffold for cell migration. Molecules include:
- fibrin
- fibronectin
- hyaluronic acid
What happens to fibroblasts in the second weak of wound healing?
Fibroblasts assume a myofibroblast phenotype
What does appearance of myofibroblasts in the 2nd week of wound healing correspond to?
The commencement of CT compaction and the contraction of the wound
