Chapter 16: The Skin

adipocyte

Fat cell

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

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 the skin.

eccrine sweat gland

Most numerous sweat-producing exocrine gland in the skin.

epidermis

Outermost layer of the 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.

lunula

The half-moon-shaped, whitish area at the base of the 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 sebaceous glands.

squamous epithelium

Flat, scale-like cells composing the epidermis.

stratified

Arranged in layers

stratum (plural: strata)

A layer (of cells).

stratum corneum

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

subcutaneous layer

Innermost layer of the skin, containing fat tissue.

adip/o

fat

albin/o

white

caus/o

burn, burning

cauter/o

heat, burn

cutane/o

skin

derm/o

skin

dermat/o

skin

diaphor/o

profuse sweating

erythem/o

redness

erythemat/o

redness

hidr/o

sweat

ichthy/o

dry, scaly (fish-like)

kerat/o

hard

leuk/o

white

lip/o

fat

melan/o

black

myc/o

fungus (fungi include yeasts, molds, and mushrooms)

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

anthrac/o

black (as coal); ex: anthracosis

chlor/o

green; example: chlorophyll

cirrh/o

tawny yellow; example: cirrhosis

cyan/o

blue; example: cyanosis

eosin/o

rosy; example: eosinophil

erythr/o

red; example: erythrocyte

jaund/o

yellow; example: jaundice

lute/o

yellow; example: corpus luteum

poli/o

gray; example: poliomyelitis

lesion

An area of abnormal tissue anywhere on or in the body

crust

Collection of dried serum and cellular debris. A scab is a crust.

cyst

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

erosion

Wearing away or loss of epidermis.

fissure

Groove or crack-like sore

macule

Flat lesion measuring less than 1 cm in diameter.

nodule

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

polyp

Growth extending from the surface of mucous membrane.

pustule

Papule containing pus. A pustule is a small abscess on the skin.

ulcer

Open sore on the skin or mucous membranes (deeper than an erosion).

vesicle

Small collection (papule) of clear fluid (serum); 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; ecchymoses

Bluish-purplish mark (bruise) on the skin.

petechia; petechiae

Small, pinpoint hemorrhage.

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.

burns

Injury to tissues caused by heat contact.

first-degree burns

Superficial epidermal lesions, erythema, hyperesthesia, and no blisters.

second-degree burns

Epidermal and dermal lesions, erythema, blisters, and hyperesthesia.

third-degree burns

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 heat, redness, pain and swelling.

eczema

Inflammatory skin disease with erythematous, papulovesicular lesions

exanthematous viral diseases

Rash (exanthem) of the skin due to a viral infection (examples would be rubella, measles, and 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

Contagious, parasitic infection of the skin with intense pruritus.

scleroderma

Chronic progressive disease of the skin and internal organs with hardening and shrinking of connective tissue.

systemic lupus erythematosus (SLE)

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

tinea

infection of the skin caused by a fungus.

vitiligo

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

callus

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

keloid

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.

nevus; nevi

Pigmented lesion of the skin

verruca

Epidermal growth (wart) caused by a virus.

basal cell carcinoma

Malignant tumor of the basal cell layer of the epidermis.

squamous cell carcinoma

Malignant tumor of the squamous epithelial cells in the epidermis

malignant melanoma

Cancerous growth composed of melanocytes.

Kaposi sarcoma

Malignant, vascular, neoplastic growth characterized by cutaneous nodules.

bacterial analyses

Samples of skin are examined for presence of microorganisms.

fungal tests

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

cryosurgery

use of subfreezing temperature via liquid nitrogen application 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 micrographic surgery

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

skin biopsy

Suspected malignant skin lesions are removed and examined microscopically by a pathologist.

skin test

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