SKIN

FUNCTIONS / DISORDERS AND BURNS

THE NAILNails- produced by epidermal cells over terminal ends of fingers and toes

Nail Body- visible part

Root- lies in a groove and hidden by a cuticle

Lunula- Crescent-shaped area nearest the root

Nail color may change color with change in blood flow.

Label the following structures: Bone, Nail root, Free Edge, Cuticle, Nail Body, Lunula

FUNCTIONS OF THE SKIN

Protection

• Against microbes• Against ultraviolet sun rays• Against harmful chemicals• Against cuts and tears

Temperature Regulation

• **** ON A HOT DAY SKIN CAN REALEASE UP TO 3000 CALORIES OF BODY HEAT A DAY.

• Regulation of sweat secretion• Regulation of blood flow close to the body surface (losing

heat by radiation) We have much more blood flow to the skin than needed, which helps regulate temperature

SKIN FUNCTIONSSense organ

• Receptors keep us informed of

• Light touch• Pressure• Hot • Cold• Pain

DISORDERS OF THE SKIN

Skin Lesions• Elevated lesions- cast a shadow outside their edges

• Papule- small firm raised lesion (warts)

• Plaque-large raised lesion Psoriasis

• Vesicle- blister filled with fluid (second degree burn)

• Pustule-pus filled lesion (Acne)

• Crust-scab (abrasion or scrape)

• Wheal- raised firm lesion with a light center (hives)

LESIONS CONTINUED

Flat lesions• Macule- Flat, discolored area (freckle)

Depressed Lesions • Excoriation- missing epidermis (a scratch)

• Ulcer- Craterlike lesion (bed sore)

• Fissure- deep crack or break ( athletes foot)

BURNS

**** Treatment and recovery depend on the total area involved and severity or depth of the burn

Estimating body surface• Use the rule of nines in adults

• Body divided into 11 areas of 9% each• Additional 1 % of body surface area around

the genitals

“RULE OF NINES”

CLASSIFICATION OF BURNS1st degree- partial thickness, only surface layers of epidermis

2nd degree- partial thickness, involve the deep epidermal layers into the upper layers of the dermis

3rd degree- complete destruction of epidermis and dermis

• May involve muscle and bone• Insensitive to pain at first because nerve endings

are destroyed. Intense pain soon follows

SKIN INFECTIONS

Impetigo- Staphylococci infection, highly contagious, usually occurs in young children

• Reddish lesion (erythema) develops a yellowish crust• Can become systemic

Tinea- fungal infection• Ring worm• Jock itch• Athletes foot

• Antifungal treatments usually help.

SKIN INFECTIONSWarts- benign neoplasm caused by papillomavirus, some can become malignant

• Usually from direct contact• Can be removed by chemicals, freezing, laser

Boils or furuncles- staph infection of the hair follicle.

• A group of untreated boils may turn into carbuncles

VASCULAR OR INFLAMMATORY SKIN DISORDERS

Decubitus ulcer- develops when pressure slows down blood flow to local areas of the skin

Uticaria or hives- red lesions called wheals caused by fluid loss from blood vessels

• Associated with severe itching• Associated with allergic reactions

Scleroderma- disorders of vessels and connective tissue. Characterized by hardening

• Localized • systemic

VASCULAR OR INFLAMMATORY SKIN DISORDERS

Psoriasis- chronic inflammatory disorder • Thought to be genetic• Inflammation accompanied by scaly plaques• Scaly plaques develop at an excessive rate

Eczema-• Most common inflammatory disorder• Inflammation often associated with papules, vesicles and

crusts• Not a distinct disease but a symptom of an underlying

condition• (Example , Contact dermatitis from poison ivy is an allergic

reaction.)

SKIN CANCER

SKIN CANCER

SKIN CANCER (3 MAIN TYPES)1. Squamous Cell Carcinoma

• Most common • Slow Growing• Hard raised nodules • If not treated it will

metastasize

2. BASAL CELL CARCINOMA

• Usually occurring on the face

• Much less likely to metastasize

• Characterized by papules with a central crater

3. MELANOMAMalignancy in a mole

Most serious type

25% chance of death

Use the ABCD method

A- Benign moles are symmetrical

B- Borders should be distinct

C- Usually evenly colored

D- Should be ¼ inch

**** most common cause of all skin cancer is UV exposure

UV damage changes DNA causing changes in mitosis

KAPOSI’S SARCOMA• Characterized by purple

lesions

• Quickly spreads to lymph nodes and internal organs

• Often associated with AIDS a other immune system disorders