Wound Healing Flashcards
What is wound healing?
The sequence of repair processes which occur to restore normal structure and function
What should be included as wound descriptors?
- Site
- Size
- Depth
- Duration
- Sepsis
- Pain
- Apprearance
- Base
- Margins
- Surrounding Skin
- Discharge
- Odour
- Foreign Bodies?
What is Serous drainage?
Clear or light yellow, thin and watery
What is Sanguineous drainage?
Red (with fresh blood), thin
What is Serosanguineous drainage?
Pink to light red, thin and watery
What is Purulent drainage?
Creamy yellow, green, white, or tan, thick and opaque
What is a wound defined as?
A break in the integrity of the epidermis
What is Primary Intention wounds?
- Simple wounds with minimal tissue loss, edges can e brought closely together
- Heal relatively quickly
- E.g. surgical incisions
What is Secondary Intention wounds?
- Complex wounds where tissue loss has occured, edges are open and cannot come together easily
- Healing is prolongued
- E.g. Trauma
How do epidermal (superficial) level wounds heal?
- Fibroblasts in the dermis contribute to the formation of a new basement membrane, upon which the epidermis will sit
- Keratinocytes in the epidermis around the wound migrate across the wound site and close it
- Epidermal growth factors stimulate cells to mitose and replace those which have migrated across the wound
- Contact inhibition occurs once epithelial cells have met, and migration stops
How are Deep wounds (Dermis and beyond levels) healed?
- Haemostasis occurs prior to wound healing
- Injury -> Bleeding -> Vasoconstriction
- Platelet adhesion to the damaged area
- Platelets aggregate together to form platelet plug
- Clotting factors react to produce fibrin mesh to bind platelet plugs together
- This is the formation of a scab
What are the four stages of wound healing?
- Inflammation
- Proliferation / Granulation
- Epithelialisation
- Maturation
What occurs in the imflammation stage of wound healing?
- Vasodilation - this leads to leakage of fluid which contain immunosubstances such as antibodies and macrophages. This helps to fight off / detect and harmful bacteria which may be near the wound
- Increased vascular permeability
- Emigration of white blood cells - released in fluid, neutrophils and macrophages mainly
What are the sings of imflammation?
- Heat
- Redness
- Swelling
- Pain
- Loss of Function
What is Angiogenesis?
The formation of new blood vessels through pre-existing blood vessels
What is the role of Macrophages release in the inflammatory stage?
- Macrophages release:
- Tumour Necrosing Factor (TNF)
- Breaks down clot to enable granulation tissue to be formed in its place
- Transforming Growth Factor (TGF)
- Promotes formation of new tissue and blood vessels
- Tumour Necrosing Factor (TNF)
What happens in the Granulation stage of wound healing?
- Fibroblasts produce collagen in random patterns to hold structures of the wound together
- This gives a framework for aniogenesis to occur
What happens in the Epithelialisation stage of wound healing?
- Epidermis cells divide and migrate from the wound edges, until they contact each other
- Fibroblasts slowly contact the edges of the wound, and contract, bringing the edges closer together
- Collagen degrades and more is produced to help close the wound
What happens in the Maturation stage of wound healing?
- Synthesis and lysis of collagen
- Remodelling of collagen to maximise the tensile strength
- Scar tissue only has 80% tensile strength of normal skin tissue
- Fibroblasts reduce in number, and blood vessels return to normal dilation as healing process completes
