Chapter 16

albino

person with skin deficient in pigment (melanin)

apocrine sweat gland

One of the large dermal exocrine glands located in the axilla and genital areas. It secretes sweat that, in action with bacteria, is responsible for human body odor.

basal layer

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

collagen

Structural protein found in the skin and connective tissue

cuticle

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

dermis

Middle layer of skin

eccrine sweat gland

Most numerous sweat-producing exocrine gland in the skin.

epidermis

outermost layer of skin

epithelium

Layer of skin cells forming the outer and inner surfaces of the body

hair follicle

Sac within which each hair grows.

integumentary system

the skin and its accessory structures such as hair and nails.

keratin

Hard protein material found in the epidermis, hair, and nails.

lipocyte

A fat cell

lunula

Half-moon-shaped, whitish area at the base of a nail.

melanin

Major skin pigment. It is formed by melanocytes in the epidermis.

paronychium

Soft tissue surrounding the nail border

pore

Tiny opening on the surface of the skin

sebaceous gland

Oil-secreting gland in the dermis that is associated with hair follicles

sebum

oily substance secreted by the sebaceous glands

squamous epithelium

Flat, scale-like cells composing the epidermis.

stratified

Arranged in layers

stratum

a layer of cells

stratum corneum

Outermost layer of the epidermis, which consists of flattened, keratinized (horny) cells.

subcutaneous layer

The innermost layer of the skin, containing fat tissue

crust

Collection of dried serum and cellular debris.

cyst

Thick-walled, closed sac or pouch containing fluid or semisolid material.

erosion

Wearing away or loss of the epidermis.

fissure

Groove or crack-like sore

macule

Discolored (often reddened) flat lesion.

nodule

Solid round or oval elevated lesion more then 1 cm in diameter.

papule

Small (less than 1 cm in diameter), solid elevation of the skin (pimples).

polyp

Benign growth extending from the surface of mucous membrane

pustule

Small elevation of the skin containing pus.

ulcer

Open sore on the skin or mucous membranes within the body.

vesicle

Small collection of clear fluid (serum); blister.

wheal

Smooth, slightly elevated, edematous (swollen) area that is redder or paler than the surrounding skin.

alopecia

Absence of hair from areas where it normally grows.

ecchymosis

Bluish-black mark (bruise) on the skin.

petechia

Small, pinpoint hemorrhages

pruritus

itching

urticaria (hives)

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

acne

Chronic papular and pustular eruption of the skin with increased production of sebum.

acne vulgaris

Buildup of sebum and keratin in pores of the skin.

comedones (blackhead)

Sebum plug partially blocking the pore.

whitehead

Pore becomes completely blocked.

burns

Injury to tissues caused by heat contact.

first degree burn

superficial epidermal lesions, erythema, hyperesthesia, and no blisters. Sunburn is an example.

second degree burn

Epidermal and dermal lesions, erythema, blisters and hyperesthesia.

third degree burn

Epidermis and dermis are destroyed (necrosis of skin) and subcutaneous layer is damaged, leaving charred white tissue.

cellulitis

Diffuse acute infection of the skin marked by local redness pain and swelling.

eczema

Inflammatory skin disease with erythematous, papulovesicular lesions.

exanthematous viral disease

Rash (exanthema) of the skin due to a viral infection. E.g. are rubella (German measles), rubeola (measles), and varicella (chickenpox).

gangrene

death of tissue associated with loss of blood supply

impetigo

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

psoriasis

chronic, recurrent dermatosis marked by itchy, scaly, red plaques covered by silvery gray scales

scabies

a contagious, parasitic infection of the skin with intense pruritus

scleroderma

a chronic progressive disease of the skin with hardening and shrinking of connective tissue

systemic lupus erythematosus

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

tinea

infection of the skin caused by a fungus

tinea Corpis

ringworm

tinea capitis

fungal infection of the scalp

tinea pedis

athlete's foot

tinea barbae

Affects the skin under the beard

tinea unguium

A fungus of the nails.

vitiligo

Loss of pigment (depigmentation) in areas of the skin. (Milky white patches)

callus

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

keloid

hypertrophied, thickened scar that occurs after trauma or surgical incision

keratosis

Thickened and reddened area of the epidermis, usually associated with aging or skin damage.

leukoplakia

White, thickened patches on mucous membrane tissue of the tongue or cheek.

nevus

pigmented lesion of the skin

verruca

epidermal growth caused by a virus, such as plantar warts, juvenile warts and venereal warts.

squamous cell carcinoma

Malignant tumor of the squamous epithelial cells of the epidermis.

malignant melanoma

cancerous growth composed of melanocytes

kaposi sarcoma

Malignant vascular neoplastic growth caracterized by cutaneous nodules.

basal cell carcinoma

a malignant tumor of the basal layer of the epidermis

cryosurgery

use of subfreezing temperature via liquid nitrogren appication to destroy tissue

curettage

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

electrodesiccation

Tissue is destroyed by burning with an electric spark.

mohs surgery

thin layers of a malignant growth are removed, and each is examined under a microscope

skin biopsy

suspected malignant skin lesions are removed and sent to the pathology laboratory for microscopic examination

skin test

Reaction of the body to a substance by observing the results of injecting the substance intradermally (within the dermis) or applying it topically to the skin.

bacterial analyses

samples of skin are sent to a laboratory to detect presence of microoganisms

fungal tests

Scrapings from skin lesions, hair specimens, or nail clippings are sent to a laboratory for culture and microscopic examination.

candidiasis

Infection caused by a yeast that typically affects the moucous membranes, vaginal mucosa and skin.