Wound Healing

Question 1

What is wound healing?

Answer 1

The sequence of repair processes which occur to restore normal structure and function

Question 2

What should be included as wound descriptors?

Answer 2

• Site
• Size
• Depth
• Duration
• Sepsis
• Pain
• Apprearance
• Base
• Margins
• Surrounding Skin
• Discharge
• Odour
• Foreign Bodies?

Question 3

What is Serous drainage?

Answer 3

Clear or light yellow, thin and watery

Question 4

What is Sanguineous drainage?

Answer 4

Red (with fresh blood), thin

Question 5

What is Serosanguineous drainage?

Answer 5

Pink to light red, thin and watery

Question 6

What is Purulent drainage?

Answer 6

Creamy yellow, green, white, or tan, thick and opaque

Question 7

What is a wound defined as?

Answer 7

A break in the integrity of the epidermis

Question 8

What is Primary Intention wounds?

Answer 8

• Simple wounds with minimal tissue loss, edges can e brought closely together
• Heal relatively quickly
• E.g. surgical incisions

Question 9

What is Secondary Intention wounds?

Answer 9

• Complex wounds where tissue loss has occured, edges are open and cannot come together easily
• Healing is prolongued
• E.g. Trauma

Question 10

How do epidermal (superficial) level wounds heal?

Answer 10

• 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

Question 11

How are Deep wounds (Dermis and beyond levels) healed?

Answer 11

• 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

Question 12

What are the four stages of wound healing?

Answer 12

• Inflammation
• Proliferation / Granulation
• Epithelialisation
• Maturation

Question 13

What occurs in the imflammation stage of wound healing?

Answer 13

• 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

Question 14

What are the sings of imflammation?

Answer 14

• Heat
• Redness
• Swelling
• Pain
• Loss of Function

Question 15

What is Angiogenesis?

Answer 15

The formation of new blood vessels through pre-existing blood vessels

Question 16

What is the role of Macrophages release in the inflammatory stage?

Answer 16

• 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

Question 17

What happens in the Granulation stage of wound healing?

Answer 17

• Fibroblasts produce collagen in random patterns to hold structures of the wound together
• This gives a framework for aniogenesis to occur

Question 18

What happens in the Epithelialisation stage of wound healing?

Answer 18

• 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

Question 19

What happens in the Maturation stage of wound healing?

Answer 19

• 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