LOM CH. 16 SKIN

integumentary system

the skin and its accessory structures such as hair, glands and nails

sebaceous glands

oil glands in the skin, they secrete sebum(oily secretion), located in the dermis

sweat glands

The glands that secrete sweat, located in the dermal layer of the skin.

Epidermis

outermost layer of skin, contains keratin

the cells here are squamous cells arranged in layers(strata) to form Stratified squamous epithelium

dermis

located just below the epidermis is a dense fibrous layer of connective tissue, it contains collagen

-it is composed of elastin and collagen

Elastin

Protein fiber found in the dermis; gives skin its elasticity and firmness.

Striae

atrophic pink, purple, or white linear streaks on the breasts, associated with pregnancy, excessive weight gain, or rapid growth during adolescence

aka stretch marks

subcutaneous layer

innermost layer of the skin, it specializes in the formation of fat

basal layer

deepest region of the epidermis; it gives rise to all the epidermal cells

stratum corneum

outermost layer of the epidermis, which consists of flattened, keratinized cells

Keratin

hard protein material found in the epidermis, hair, and nails

Melanocytes

cells that produce melanin

they give color to the skin the more melanin within each cell accounts for different skin colors

albinos

individuals who are incapable of forming melanin

hair follicle

sac within which each hair grows

Nails function

Protect and support tips of fingers and toes

they are composed of hard keratin plates

fingernails grow about 1 mm a month, they can completely regrow in about 3 to 5 months

toenails grow slower and it usually takes a year to completely regrow a toenail

Lunula of nail

the half moon shaped, white area at the base of the nail

Cuticle

Band of epidermis at the base and sides of the nail plate

Onycholysis

separation of the nail plate from the nail bed

it may occur with infection of the nail and is often seen in people who suffer from psoriasis

eccrine sweat glands

most numerous sweat-producing exocrine gland in the skin

pore

tiny opening on the surface of the skin

apocrine sweat glands

active from puberty on, concentrated near reproductive organs and armpits

they secrete an odorless sweat but the sweat is easily broken down my bacteria on the skin when this happens then an odor is produced

(the mammary apocrine gland produces milk after childbirth)

adip/o

fat

albin/o

white

caus/o

burn, burning

cauter/o

heat, burn

cutane/o

skin

derm/o, dermat/o

skin

diaphor/o

profuse sweating

erythem/o, erythemat/o

redness

hidr/o

sweat

ichthy/o

dry, scaly

kerat/o

hard

leuk/o

white

lip/o

fat

melan/o

black

myc/o

fungus

onych/o

nail

phyt/o

plant

pil/o

hair, hair follicle

py/o

pus

rhytid/o

wrinkle

seb/o

sebum

squam/o

scale-like

steat/o

fat

trich/o

hair

ungu/o

nail

xanth/o

yellow

xer/o

dry

Crust

collection of dried serum and cellular debris

cyst

sac containing fluid

Erosion

wearing away or loss of epidermis

fissure

groove or crack-like sore

macule

flat, pigmented lesion measuring less than 1 cm in diameter

nodule

solid, round or oval elevated lesion 1 cm or more in diameter

papule

small, solid elevation of the skin (less than 1 cm in diameter)

polyp

growth extending from the surface of mucous membrane

pustule

papule containing pus

ulcer

open sore or lesion in the skin or mucous membrane (deeper than erosion)

Vesicle

small collection of clear fluid; blister

wheal

smooth, edematous (swollen) papule or plaque that is redder or paler than the surrounding skin

alopecia

absence of hair from areas where it normally grows

Ecchymosis

bluish-purplish mark (bruise) on the skin

petechia

small, pinpoint hemorrhage

pruritus

itching associated with dermatitis

acne

chronic papular and pustular eruption of the skin with increased production of sebum

first degree burn

Superficial burns through only the epidermis.

no blisters

second degree burn

a burn involving the epidermis and the dermis; characterized by erythema, hyperesthesia, and vesications (blisters)

third degree burn

A full-thickness burns that involve the epidermis, dermis, and varying levels of the subcutaneous and underlying structures.

leaves charred white tissue

Cellulitis

diffuse, acute infection of the skin marked by local heat, redness, pain, and swelling

seen many times with chemotherapy as a result of damage to the lymph system

eczema (atopic dermatitis)

inflammatory skin disease with erythematous, papulovesicular, or papalosquamous lesions

usually accompanied with pruritus(itching)

exanthematous viral disease

rash (exanthem) of the skin due to a viral infection

some examples are rubella(german measles), rubeola(measles), and varicella(chicken pox), and hand-foot-mouth disease

gangrene

death of tissue associated with loss of blood supply

common with frostbite and diabetes

Impetigo

bacterial inflammatory skin disease characterized by vesicles, pustules, and crusted-over lesions

caused by staph or strep bacterial strains

Psoriasis

chronic skin condition producing red lesions covered with silvery scales

it is not infectious or contagious

it is autoinflammatory that can run in families

treatment is only palliative(relieving but no cure)

Scabies

contagious, parasitic infection of the skin with intense pruritus

often seen in the groin, nipples and skin between the fingers

treatment is topical cream to destroy scabies mites

scleroderma

is an autoimmune disease where fibrous scar like tissue forms in the skin, heart, lungs, kidney and esophagus some changes of pigmentation may be seen

systemic lupus erythematosus (SLE)

chronic autoimmune inflammatory disease of collagen in skin, joints, and internal organs

seen with a butterfly red rash over the cheeks and nose

primarily seen in females

tinea

infection of the skin caused by a fungus

many types, tinea corporis or ringworm, tinea pedis or athlete's foot treated with antifungal

they are highly contagious and cause severe pruritus(itching)

Uticaria(hives)

acute allergic reaction in which red, round wheals develop on the skin

vitiligo

localized loss of skin pigmentation characterized by milk-white patches

it is a form of leukoderma

callus

increased growth of cells in the keratin layer of the epidermis caused by pressure or friction

keloid

excess hypertrophied, thickened scar developing after trauma or surgical incision

keratosis

thickened and rough lesion of the epidermis; associated with aging or skin damage

Leukoplakia

white, thickened patches on mucous membrane tissue of the tongue or cheek (evolves to squamous cell carcinoma)

nevus, nevi

pigmented lesion of the skin, benign

verruca

epidermal growth (wart) caused by a virus

____ vulagaris(common wart)

basal cell carcinoma

malignant tumor of the basal cell layer of the epidermis

it is the most common skin cancer

squamous cell carcinoma

malignant tumor of the squamous epithelial cells in the epidermis

it can grow other places than the skin, wherever squamous epithelium is found(mouth, larynx, bladder, esophagus, lungs)

sun damage can be a precursor

malignant melanoma

cancerous growth composed of melanocytes

they often metastasize to the lung, liver, bone, and brain

often related to exposure to ultraviolet light

there may be a genetic predisposition

Kaposi's sarcoma

malignant, vascular, neoplastic growth characterized by cutaneous nodules

often seen in the lower extremities

one form is associated with AIDS

cryosurgery

use of subfreezing temperature to destroy tissue

achieved with liquid nitrogen

curettage

use of a sharp dermal curette to scrape away a skin lesion

electrodesiccation

tissue is destroyed by burning with an electric spark

can be used with curettage to destroy small cancerous lesions that have well defined borders

Mohs surgery

thin layers of malignant tissue are removed, and each slice is examined under a microscope to check for adequate extent of the resection

used mainly with basal cell carcinoma, squamous cell carcinomas, and other tumors

skin biopsy

suspicious skin lesions are removed or sampled and examined microscopically by a pathologist

skin test

substances are injected intradermally or applied to the skin, and results are observed