ABSITE Review - Wound Healing Flashcards
What are the phases of wound healing? What cells are involved in each phase?
Inflammation (days 1-10) - PMNs, macrophages; epithelialization 1-2mm/day
Proliferation (5 days-3 weeks) - fibroblasts, neovascularization, production of collagen, granulation tissue
Remodeling (3 weeks-1 year) - type III collagenreplaced with type I; decreased vascularity
What is the order of cell arrival in wound?
PLTs –> PMNs (day 0-2) –> Macrophages (day 3-4) –> Fibroblasts (day 5 & on) –> Lymphocytes
How fast peripheral nerves regenerate?
1mm/day
What is the main cell involved in wound healing?
Macrophages due to release of growth factors and cytokines
What are the dense granules?
Adenosine, serotonin, calcium
What is the most important factor in healing an open wound?
Epithelial integrity
What is the most important factor in healing an closed wound?
Tensile strength
What is the strongest layer in a bowel anastomosis?
Submucosa
What cell is involved in wound contraction?
Myofibroblasts
Mention all types of collagen and where are they found.
Type I - MC type of collagen: skin, bone and tendons; Primary collagen in a healed wound
Type II - Cartilage
Type III - Increased in healing wound, also in blood vessels and skin
Type IV - Basement membranes
Type V - Widespread, particularly found in the cornea
What substances are required for hydroxylation of proline and subsequent cross-linking of proline residues in wound healing?
Alpha-ketoglutarate, vitamin C, oxygen and iron
What are the two MC AAs in collagen?
Proline every 3rd residue and abundant lysine
What effect has d-Penicillamine on collagen cross-linking?
Inhibits collagen cross-linking
What are some impediments to wound healing?
Bacteria > 105/cm2 - decrease oxygen content, collagen lysis Devitalized tissue and foreign bodies Cytotoxic drugs - 5FU, MTX, CSA Diabetes Albumin <3 Steroids - give Vitamin A 25,000IU qd
What is Charcot’s joint?
Diabetic foot ulcer with 2nd MTP joint involvement
