wound healing and tissue repair II - lecture notes - julia Flashcards
what is a wound?
any type of disruption in the integrity of an organ or tissue
what is a scab?
- coagulum that forms over a surface defect
- initial attempt to seal
- will have coagulation proteins, serum proteins, etc.
what is granulation tissue? (where in the body is it found, what does it consist of?)
- early phase of the formation of a scar anywhere in the body except the brain
- composed of very early capillaries, activated fibroblasts, new, watery ECM, lots of leukocytes
what is a scar?
- mature collagen that has become relatively hypovascular
what is a keloid?
situation on the skin where a wound has healed but the formation of collagen never stopped - keeps piling up
what is cicatrix?
scar
what processes does repair by connective tissue (scaring) involve? (list)
- angiogenesis
- migration and proliferation of fibroblasts
- deposition of ECM
- maturation of fibrous tissue (remodeling)
what coagulation factor activities are involved in wound healing?
- hageman factor fragments
- bradykinin
- complement activation
- fibrin clot
what is the effect of hageman factor fragments?
vasopermeability
what is the effect of bradykinin?
- vasodilation
- vasopermeability
- pain
what is the effect of complement activation?
- leukocyte recruitment
- vasopermeability
what is the effect of fibrin clots?
- hemostatic plug
- reseroir of growth factors
- provisional matrix for cell migration
what are the roles of platelets in wound repair? (list)
- adhesion
- aggregation
- mediator release
what is the effect of adhesion of platelets?
plug small leaks in blood vessels
what is the effect of aggregation of platelets?
- plug large leaks in blood vessels
- induce coagulation
what is the effect of mediator release by platelets?
- vasoconstriction
- stimulate additional platelet aggregation
- growth factor release
what growth factors are active in wound healing?
- FGF (fibroblast growth factor)
- PDGF (platelet-derived growth factor)
- TGF-B (transforming growth factor)
- VGEF (vascualar endothelial growth factor)
what is the effect of FGF?
- fibroblast and epidermal cell proliferation
- angiogenesis
what is the effect of PDGF?
- fibroblast chemotaxis, proliferation and contraction
what is the effect of TGF-B?
- fibroblast chemotaxis
- ECM deposition
- protease inhibitor secretion
what is the effect of VGEF?
- vascular permeability
- angiogenesis
what is the role of macrophages in wound repair?
- recruitment and maturation
- phagocytosis and killing of microorganisms
- pahgocytosis of tissue debris
- growth factor release
what is the effect of recruitment and maturation of macrophages in wound healing?
transition from ciruclating monocyte to tissue macrophage
what is the effect of macrophage phagocytosis and killing of microorganisms in wound repair?
wound decontamination
what is the effect of macrophage phagocytosis of tissue debris in wound repair?
wound debridement
what is the effect of macrophage growth factor release in wound repair?
autocrine and paracrine stimulation
what GFs cause monocyte chemotaxis?
- PDGF
- FGF
- TGF-B
what GFs cause fibroblast migration?
- PDGF
- EGF
- FGF
- TFG-B
- TNF
what GFs cause fibroblast proliferation?
- PDGF
- EGF
- FGF
- TNF