Chapter 2: Dermatology - The Integumentary System

Integumentary System

the body's largest organ system, consisting of the skin, hair, nails, subcutaneous tissue, and glands

Dermatology

The medical specialty that studies the anatomy and physiology of the integumentary system.

Functions of the integumentary system

Protection, repair, sensation, synthesis of vitamin D, and thermoregulation

Integument/o

skin

Two layers of the skin

Epidermis and Dermis

Dermis

thick and lies below the epidermis. Made of connective tissue. Adj for dermis is dermal

Epidermis

the thin outermost layer.

Hypodermis

also called subcutaneous (SQ, subQ). Below the dermis. Thickness varies with the amount of fat stored

Cutane/o

skin

Dermatisis

any infection or inflammation of the skin

Pruritus

The condition of itching: may be associated with many diseases, especially allergic reactions on the skin

Rash

A rash can cause pruritis. A red or pink skin lesion that is flat or raised, itchy or not itchy.

Xeroderma

Excessively dry skin

Xer/o

dry

Edema

Swelling from excessive amounts of fluid that move from the blood into the dermis or hypodermis

Severe edema is known as

pitting edema

Syndactyly

Condition in which the skin and tissues between the toes or fingers are joined

Syn

together

Dactyly

condition of fingers or toes

Lesion

any area of visible damage on the skin or a variation from normal skin

Scale

Excess of epidermal cells produced. Flat to slightly elevated, thin flake. No contents. White in color.

Examples of scales

Psoriasis or dandruff

Wheal

Fissure

Crack lick structure in the skin. Color: Erythema

Macule

Flat circle. Pigmented brown or black

Example of a macule

freckle or age spots

Papule

Elevated skin color or erythema: acne

Pustule

Elevated white top: white head

Neoplasm

New growth on the skin. Benign or malignant. (Neo = new) (Plasm = growth)

Actinic keratosis

raised, rough areas due to chronic sun exposure

actin/o

rays of the sun

kerat/o

hard, fibrous protein

Hemangioma

Mass of superficial, dialated blood vessels present at birth: usually dissapears without treatment

Lipoma

rounded growth of adipose tissue in the skin

lip/o

fat

Nevus

Lesion that comes in a variety of shapes and coloes present at birth (mole or birthmark)

Papilloma

Soft, flesh-colored growth that protudes from the skin. Can grow as a flap or polyp (skin tag)

Senile lentigo

Light to dark brown, flat macules on the skin in areas exposed to the sin (age spots or liver spots)

Basal cell carcinoma

Begins in the bottom layer of the epidermis (stratum basale): slow growing cancer that appears as a raised, pearly bump

Squamous cell carcinoma

Begins in the epidermal layers superficial to stratum basale: slow growing red bump or ulcer

Matastisis

able to spread

Malignant melanoma

Begins in melanocytes of epidermis fast growing and spreading cancer

Melan/o

black (melanin)

ABCDE for Malignant Melanoma (A)

Asymemety

ABCDE for Malignant Melanoma (B)

Irregular border

ABCDE for Malignant Melanoma (C)

Varied coloring

ABCDE for Malignant Melanoma (D)

large diameter

ABCDE for Malignant Melanoma (E)

evolving size increase

Erythema

red discoloration of the skin: local or over large areas

eryth/o

red

Ema

condition

Jaundice

yellowish discoloration of the skin, mucous membranes, and sclera due to inability od the liver to process bilirubin

What causes jaundice?

Liver processes bilirubin which is excreted via feces

Albinism

genetic mutation in which melanocytes do not produce melanin: lack of color in skin, hair, and eye

Albin/o

white

Cyanosis

A bluish purple discoloration of the skin and nails

Vitiligo

Automimmune disease in which melanocytes are slowly destroyed and patches of depigmentation appear (progressive)

Vitim

defect

Necrosis

Gray to balck discoloration of the skin due to death from a burn, ulcer, wound, poor blood supply, freezing temps

Necr/o

dead tissue

Gangrene

bacterial infection and decay of the necrotic tissue

Callus

thickening of the epidermis of areas subject to wear and tear

Cicatrix

Collagen that forms as injury heals (scar)

Hemorrhage

Injury to blood vessels that releases blood into the skin

rrhage

excessive flow

Abrasion

sliding or scraping injury that mechanically removes the epidermis

Excoriation

linear scratch on the skin (cat scratch)

Keloid

abnormally large scar that grows larger than the original injury due to overproduction of collagen

kel/o

tumor

oid

resembling

Laceration

linear penetrating wound

lecer/o

tearing

Decubitus ulcer

ulcer in the skin causes by epidermal and dermal breakdown associated with constant pressure on the skin that decreeases blood flow over bony areas (bed sore)

Decubitus

lying down

Blister

epdiermis separates from dermis. fluid filed sac with a thin, transparent covering of epidermal cells: caused by repetitive rubbing

Burns

Caused by heat, hot objects, steam, water, electricity, chemicals, and radiation

Superficial burns

epidermis damaged (sunburn)

Partial-thickness burn

Epidermis and part of dermis damaged (blisters common)

Full-thickness burns

Epidermis and dermis fully damaged

Eschar

thick scar of necrotic tissue that forms with a full-thickness burn. Must be removed because infection can occur

Abscess

localized pus-containing pocket

Furuncle

abscess around a hair follicle

Carbuncle

several furuncles

Cellulitis

infection or inflammation of the connective tissues of the skin

Shingles

Infection with herpes varicella-zoster virus (chicken pox) If you have had chicken pox

Shingles occurs…

The lesions occur along a dermatome (an area of skin associated with a specific spinal nerve that goes to the spinal cord)

Verruca

Rough, irregular skin lesion caused by the

human papillomavirus; occurs on hands,

fingers, or soles of the feet.

• Known as a wart

Tinea

Fungal infection (commonly referred to as

ringworm) of the skin; severe itching and

burning with red, scaly lesions.

Tinea capitis

head

• Tinea corporis

body

Tinea cruris

jock itch

Tinea pedis

athletes foot

Pediculosis

Infestation of lice and their eggs (nits); can

occur in the scalp, hair, eyelashes, and

genital area.

Scabies

Infestation of parasitic mites that tunnel

under the skin and produce itchy vesicles;

caused by the same parasite that causes

mange in dogs.

Contact dermatitis

Dermatitis caused by physical contact with an

allergen or irritant like deodorant, soap, makeup,

or urine.

Urticaria

Local allergic reaction to food, plants, animals,

insect bites, or drugs; caused by release of

histamines and involves raised areas of redness

and edema that occur suddenly; very itchy

• Also known as hives

Each individual inflamed area is a

wheal

A large wheal is a

welt

Psoriasis

Autoimmune disorder in which too many

abnormal epidermal cells are produced; produces

itch, silvery scales, and plaques.

Systemic lupus

erythematosus

(SLE)

Autoimmune disorder; collagen in the skin and

connective tissues deteriorates;

characterized by butterfly rash on nose and

cheeks.