Anatomy: Healing of Wounds and Burns

inflammation

- tissue response to stress that includes dilation of blood vessels and fluid accumulation in the affected region

- dilation results in increased permeability to allow fluids to leak into damages tissues

- supply nutrients and oxygen

fibrin

- fibrous protein that traps platelets in fibers to form blood clots

scab

- blood clot and dried fluids that cover and protect underlying tissues

scar

- in deep cuts, extensive production of collagen fibers may form an elevation above

superficial partial-thickness (first-degree) burn

- a burn injuring only the epidermis

- erythema:

- mild edema

- surface layer may be shed

- healing usually occurs within a few days to 2 weeks

- no scarring

- example: minor sunburn

deep partial-thickness (second-degree) burn

-a burn that destroys some epidermis as well as some underlying dermis

- fluid escapes from damaged dermal capillaries and accumulates beneath) outer layer of epidermal cells (blisters)

- injured region becomes moist and firm

- may vary from dark red to waxy white

- example: exposure to hot objects, hot liquids, flames, or burning clothing

- healing: depends on stem cells associated with accessory structures of the skin

- survive because derive from dermis

- stem cells divide and daughter cells grow out onto surface of dermis and spread over it and differentiate as new dermis

- scar tissue only occurs if infected

full-thickness (third-degree) burn

- a burn that destroys the epidermis, dermis, and the accessory structures of the skin

- injured skin becomes dry and leathery

- may vary in color form black to white

- most epithelial cells are destroyed

- spontaneous healing can occur only by growth of epithelial cells inward from the margin of the burn

autograft

- transplant within the same individual of unburned region to burned region

allograft

- transplant from person to person when too extensive for autograph

- can use cadaveric skin

- temporary covering

- shrinks the wound

- helps prevent infection

- preserves deeper tissues

cold sore

- infection caused by virus

contact dermatitis

- exposures cause allergic reaction

- from coming into contact with something

psoriasis

- cause is unknown

- triggered by trauma, infection, stress

benign

- type of cancer

- does not spread (encapsulated)

malignant

- type of cancer

- metastasized (moves) to other parts of the body

basal cell carcinoma

- least malignant type of skin cancer

- most common type

- arises from stratum basale

squamous cell carcinoma

- skin cancer

- metastasizes to lymph nodes if not removed

- early removal allows a good chance of cure

- believed to be sun-induced

- arises from stratum spinosum

malignant melanoma

- most deadly of skin cancer

- cancer of melanocytes

- metastasizes rapidly to lymph and blood vessels

- detection uses ABCD rule

ABCD rule

- A = asymmetry (different size/shape)

- B = border irregularity (not smooth)

- C = color (different colors)

- D = diameter (spot is larger than 6 mm in diameter)

rule of nines

- way to determine extent of burns

- body is divided into 11 areas

- each area represents about 9% of total body surface area

- allows for fluid volume replacement to be calculated correctly

phagocyte

- macrophage

- a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles

- aids in immunity function of skin

erythema

- superficial reddening of the skin, usually in patches

- result of injury or irritation causing dilatation of the blood capillaries