Wound Healing & Tissue Repair Flashcards
How does first and second intention wound healing differ?
First intention occurs in wounds with opposed edges. Second intention occurs in wounds with separate edges and involves a more prominent inflammatory reaction and scar formation
TGF-B & PDGF have similar functions. What is the primary difference between these proteins, with respect to function?
TGF-B inhibits collagenase, while PDGF secretes collagenase to eliminate immature collagen
What proteins stabilize and promote neovascularization during tissue repair?
APO 1 - recruits pericytes
PDGF - recruits smooth muscle
TGF-B - stabilizes vessels
What types of cells have a high replacement capacity?
Labile cells
What process follows tissue damage when the original tissue architecture is intact, with little destruction?
Resolution
What protein is especially important for angiogenesis as part of wound repair?
FGF - also has all the functions of TGF-B
What proteins function in monocyte chemotaxis, fibroblast migration, and collagen synthesis?
TGF-B & PDGF
What immune cell is first present following a tissue injury?
Neutrophils - they are replaced by macrophages after ~24 hours
What proteins act as fibrogenic cytokines?
TNFa & IL-1
Hematopoietic stem cells are capable of producing what other types of cells?
Blood cells, bone marrow, hepatocytes, neurons
A patient is 1 month post-surgery and wants to begin vigorous activity. The surgeon advises against this. Why is this?
1-month post-op, the tissue has regained only approx. 20% of its original strength. Wounds can take 6-12 months to regain full strength
What is it called when scar tissue grows beyond the bounds of the wound and will not regress?
Keloid
True/False. Any level of inflammation will initiate repair processes.
True
True/False. Tissue remodeling is a balancing act. Collagen and EGM is constantly degraded and maintained.
True. MMPs degrade collagen and ECM, while TIMPS inhibit MMPs
An ulcer forms over a wound. What is the primary reason why this may occur?
Inadequate vascularization
What are the functions of VEGF?
Promotes angiogenesis, endothelial migration & proliferation, increases vascular permeability
What zinc-dependent protein degrades collagen and ECM during tissue remodeling?
Matrix mettaloproteinases
What factors may influence wound healing?
Age, nutritional deficiencies, metabolic diseases, catabolic state, systemic drugs
What type of collagen forms the primary scar?
Collagen I
What is contracture?
Contracture is the pulling of the tissue together during wound repair. Exaggeration of this process can cause deformities in the tissue
What protein is most important in fibroblast proliferation and is present in chronic fibrotic diseases?
TGF-B
What is it called when a wound ruptures due to increased abdominal pressure?
Wound Dehiscence
What tissue repair proteins have intrinsic tyrosine kinase activity?
EGF & FGF
