Skin

Question 1

Layers of the skin

Answer 1

Epidermis

• Superficial
• Deep (pigmented + regenerative)
• Avascular

Dermis

• Dense layer of interlacing collagen and elastic fibres
• Vascular
• Predominate direction of fibres leads to characteristic tension in tissue
• Deep dermis contains hair follicles and smooth arrector muscles (L. musculi arrector pili)

Subcutaneous tissue

Superficial fascia

Question 2

Langer lines

Answer 2

Lines of tension across the skin

• Transverse for neck and trunk
• Spiral longitudinally in limbs

Incisions across lines gape –> prolonged, poor healing and scarring

Incision parallel to –> don’t gape –> better cosmesis

Question 3

Superficial burns

Answer 3

Epidermis only

• Erythema
• Sensate –> Painful
• 3 days to heal

Question 4

Partial thickness burns

Answer 4

Epidermis and Dermis involved

Superficial partial thickness

• Epidermis and superficial layer of dermis involved
• Blister as fluid collects between dermis and epidermis
• Sensate – > painful
• Erythematous

Deep partial thickness

• Epidermis and deep layer of dermis involved
• Hair follicles may remain intact, need to wait for areas to declar themselves

Question 5

Full-thickness burns

Answer 5

Epidermis + Dermis + Subcutaenous tissue involved

• Hair follicles and sweat glands destroyed
• No re-epithelisation to epidermis
• Require skin grafts or they will heal by secondary intention –> scarring and contractures

Question 6

Fourth degree burns

Answer 6

Epidermis + epidermis + subcutaneous tissue + fascia / bone