Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
What is the lag phase of wound healing
|
Inflammatory period 1-5 days post injury, the wound is not gaining strength
|
|
|
What are the stages and approximate time periods for wound healing
|
Inflammatory 1-5 days
Repair Fibroblastic 3-5 days pi Epithelialization Contraction 5-9 days pi Maturation 1-2 years |
|
|
What activities take place in the inflammatory stage
|
Transient vasoC followed by vasoD and leakage of small venules - edema
Vasoactive compounds released by platelets, mast cells - rounding of endo cells Leakage of Abs, compliment, clotting factors WBC's become sticky and diapedese (within 1 hour) |
|
|
What are some functions of platelets
|
Clot formation
VasoC (TxA4) PDGF (a granules), platelet factor 4, PAF - attract inflammatory cells and fibroblasts and stimulates MP production of TGF-B |
|
|
When do Neutrophils and Monocytes arrive, what is their purpose
|
6-12 hours
Neutrophils - phagocytize bact and debris, release lysozymes, short lived Monocytes - differentiate into MP |
|
|
What is contact inhibition
|
When ruffled membranes of 2 like cells meet - migration stops and cells start 'piling up'
|
|
|
Where do fibroblasts come from, how do they enter a wound
|
Derived from local mesenchymal cells, especially those associated with vascular adventitia
Move in using cytoplasmic extensions (ruffled membranes) along a fibrin scaffold as soon as debris is cleared |
|
|
What gives granulation tissue its 'granular' appearance
|
Capillaries formed by endothelial budding
|
|
|
What do fibroblasts produce, how does it help in healing
|
Collagen (day 4-5), barrier to infection, surface support of epithelial migration
|
|
|
What is contact guidance
|
The migrationof epithelial cells by sliding over each other guided by fibirin and collagen network until they contact epithelium from the other side of wound (contact inhibition)
|
|
|
What process takes place after contact inhibition occurs with epithelial cells
|
Mitosis
|
|
|
What is contraction, which cells mediate this process
|
the process by which wound size decreases; fibroblasts and myofibroblasts (5-9 days pi)
|
|
|
What are the characteristics of myofibroblasts
|
smooth muscle elements, rapidly increas in # during contraction, cell-cell and cell-wound edge connections
|
|
|
When does contraction stop
|
Either due to contact inhibition or when tension = contractile forces
|
|
|
Inappropriate contraction leads to...this is most important on what type of surfaces
|
Contracture; flexion surfaces
|
|
|
What takes place during maturation
|
Collagen fibers reorient in the direction of stress, collagen cross-links, ultimate strength is reached = 80% of normal
|
|
|
What is primary closure
|
Closure immediately following wound (surgery)
|
|
|
What is delayed primary closure
|
Closure <6 hours post injury, clean of infection, prior to granulation tissue formation
|
|
|
What is secondary closure
|
Closure of would after granulation tissue has formed
|
|
|
What is second intention healing
|
No surgical intervention, wound closes solely by progression through inflammation, epithelialization, and contraction
|
|
|
Failure of primary closure can result in what two types of closure
|
Secondary closure or second intention healing
|
|
|
What are the steps to follow with any wounded animal
|
Assess animal/wound
Debride and lavage Decide what to put in/on wound Debriding bandage |
|
|
What are the components of a wet to dry bandage
|
Layer 1 - wet sterile saline soaked gauzes
Layer 2 - dry absorbent material Layer 3 - semiocclusive material |
|
|
What are some products used to prevent bacterial growth under bandage
|
Saline, sugar, maltodextran, tripeptide copper, SSD, honey, acemannan, triple antibiotic
|
|
|
When is a tie-over bandage used and what are the components
|
Used when you can't wrap all the way around a structure
Suture loops around wound, place wet dry bandage layers, string umbilical tape through loops |
|
|
What bandage changes do you make once granulation tissue has formed
|
Use nonadherent bandage
|
|
|
When creating or closing a large wound we must determine the direction of closure resulting in the least amount of tension at wound edge because
|
Tension = Failure
|
|
|
What are three suture patterns or techniques that can be used to relieve tension at the incision/closure
|
Subdermal sutures, walking sutures, external tension relieving sutures
|
|
|
What are some other methods of relieving tension
|
Stents - made from rubber tubing
Stretching the skin - using velcro or a substance that allows you to stretch the skin a little each day |
|
|
How do you manage a dog that comes to the clinic with a bite wound on its thorax
|
Assess patient (PE), look for pneumothroax (immediate surgery)
If patient is stable and wound is <6 hrs small defects can be debrided and allowed to heal via second intention large wounds can be debrided and closed by delayed primary wounds >6 hrs/infected - debride, use wet/dry bandage until tissue has granulated over then switch to nonadherent bandage - secondary closure or allow second intention healing depending on size |
