Surgical Technology Flashcards
(111 cards)
Outline the layers of the skin
- Epidermis
- Dermis
- Hypodermis/Subcutaneous
Epithelium of the epidermis
Keratinised squamous epithelium
Where do the skin’s natural tension lines lie
Right angles to the angle of contraction of the underlying muscle
What constitutes a superficial wound
Involve only epidermis and dermis
What constitutes a deep wound
Involve layers deep to the dermis
Describe primary intention wound healing
- Occurs in uncontaminated wounds with minimal tissue loss
- Wound edges easily approximated
- Wound heals by rapid epithelialisation and formation of minimal granulation tissue
Describe secondary intention wound healing
- Occurs in wounds with substantial tissue loss
- Wound is left open and allowed to heal from deep aspects by granulation, epithelialisation and contraction
Describe tertiary intention wound healing
- Wound is closed several days after its formation
- e.g. Delayed primary closure
List the 3 phases of wound healing
- Acute inflammatory phase
- Proliferative phase
- Maturation phase
Outline the inflammatory phase of wound healing
- Initial trauma
- Vasodilatation and increased vascular permeability
- Influx of inflammatory cells (neutrophils) and fibroblasts
- Platelet activation and initiation of the coagulation and complement cascades
When do neutrophils arrive at the wound
0-1 days
When do macrophages arrive at the wound
1-2 days
When do fibroblasts arrive at the wound
2-4 days
When do myofibroblasts arrive at the wound
2-4 days
When do endothelial cells arrive at the wound
3-5 days
Outline the proliferative phase of wound healing
Characterised by migration and proliferation of:
- Epithelial cells
- Fibroblasts
- Endothelial cells
When is epithelial closure usually achieved
48 hours
What is the role of fibroblasts in the proliferative phase of wound healing
Synthesise extracellular matrix components including collagen and ground substance
What is granulation tissue
Temporary structure that forms during the proliferative stage. Contain capillaries, fibroblasts, macrophages and endothelial cells. Has a characteristic pink, granular appearance.
How long does skin take to regain full strength
6 months
How long does bowel and muscle take to regain full strength
1 month
How long does full maturation of the scar take
12-18 months
What vitamin aids the cross-linking of the fibrils in matrix remodelling
Vitamin C
Describe Neuropraxia
- Temporary and reversible loss of function lasting 6-8 weeks (motor function first to be lost)
- No axonal disruption
- Crush, stretch, or contusion of the nerve