Surgical Wound Healing Flashcards
- Involves epidermis and dermis w/o total penetration of dermis
- minimized scarring
- most surgical wounds healed by this
Primary Intention
- wound allowed to granulate
- process slowed by drainage from infection
- leaves big scar
Secondary Intention
- delayed primary closure
- wound cleaned, debrided, and observed 4-5 days prior to closure
- wound purposely left open
Tertiary intention
What hormone is decreased in response to injury?
TSH
-everything else is increased
What happens in the early phase of metabolic response to injury?
- dec body cell mass
- VASOCONSTRICTION -to conserve volume
- change in energy source
What are the stages of tissue healing?
- inflammation
- repair/fibroblastic
- remodeling
what factors are involved in the vascular and inflammatory phase?
- subendothelial factor VII
- hageman fator xii
- platelet derived growth factor
- histamine
what process is critical for a wound to be considered ‘healed’?
re-epithelization phase
what is the initial event of re-epithelization
-migration of undamaged epidermal cells from the wound edges
what is important for the migration of undamaged epidermal cells from wound margins?
water content because cells seek level of critical humidity
why do ulcers have a HPK rim?
there is increase in epithelial proliferation at wound margins
What is this?
- crosslinks with fibrin to provide matrix for cell adhesion and migration
- promotes phagocytosis
- forms scaffolding for collagen deposition
-Fibronectin
What is granulation tissue made up of?
- inflammatory cells
- fibroblasts
- new vasculature in hydrated matrix of glycoproteins
- collagen
- GAGs
What factors are involved in fibroplasia and matrix formation?
EGF-epidermal growth factor
MDGF-macrophage derived
PDGF-platelet derived
what are the processes of fibroplasia and matrix formation?
- differentiation of myofibroblast
- fibronectin crosslinks
- migration of myofibroblast
- type 3 collagen fibers on scaffold
what contracts in wound contraction?
-myofibroblasts and the attached surrounding tissue “fibronexus”
What is a fibronexus?
-intimate association between the membrane of myofibroblasts, intracellular actin and extracelluar fibronectin