Chapter 23: Med Surg Flashcards
epidermis
thin, superficial layer of skin; 0.05-0.1 mm thickness and nourished by blood vessels in dermis; regenerates every 28 days
melanocytes
contained in deep basal layer (germinativum) of the epidermis; contain melanin (gives skin and hair color) and protects from UV
keratinocytes
synthesized from epidermal cells in basal layer, they move to surface of epidermis to die and form corneum (horny cell layer); protective barrier
dermis
1-4 mm thickness, 2 layers: papillae forms fingerprints and footprints and reticular layer forms collagen
collagen
forms the greatest part of the dermis and responsible for strength; composed of fibroblasts which are important for wound healing
subcutaneous tissue
not part of skin, provides insulation, provides shock absorption
sebaceous glands
prevent skin and hair from drying; abundant on face, scalp, upper chest, and back, not palms and soles
apocrine sweat glands
located in the axillae, breast, tummy, external auditory canals, and eyelids; thick milky substance and become odorous at puberty
eccrine sweat glands
widely distributed except on lips; cools the body from evaporation and excretes waste products through the pores of the skin
insensible perspiration
600-900 mL/day lost and helps maintain homeostasis through fluid and electrolyte balance
gerontologic differences with skin
decreased extracellular water and sebaceous glands, increased capillary fragility which causes bruising, increased melanocytes in basal layer which cause solar lentigines, decreased estrogen causing baldness, increased keratin causing longitudinal ridging of nails
actinic keratoses
areas of chronic sun exposure, increased risk for BCC & SCC
normal nails
160 degrees
intertriginous
skin surfaces overlap and rub on each other
primary skin lesions
occur on previously unaltered skin
secondary skin lesions
change with time or occur because of factors such as scratching or infection
macule
circumscribed, flat discoloration < 0.5 cm: freckles, petechiae
papule
elevated solid lesion up to 0.5 cm: wart, BCC
vesicle
defined collection of (serous or free fluid up to 0.5 cm: chicken pox, 2nd degree burn
plaque
circumscribed, elevated solid lesion formed by confluence of papules: psoriasis and keratoses
wheal
firm plaque caused by fluid in dermis: insect bite
pustule
circumscribed collection of leukocytes and free (purulent) fluid: acne, impetigo
fissure
linear loss of epidermis to dermis: athlete’s foot or cracks at corner of mouth
scale
excess dead epidermal cells: flaking of skin
scar
abnormal formation of connective tissue that replaces normal skin
ulcer
irregular, crater-like loss of the epidermis and dermis: pressure ulcer and chancre
atrophy
depression in skin resulting from thinning of the epidermis or dermis: aged skin, striae
excoriation
epidermis is missing and exposed dermis: abrasion or scratch
angioma
benign tumor of blood or lymph vessels: increased with age, liver disease, pregnancy
ecchymosis for dark skin
purple to brownish black
erythema for dark skin
deeper brown to purple with increased skin temperature
pallor for dark skin
underlying red tone in brown or black is absent, light African americans have yellowish brown skin, dark skinned may have ashen gray
petechiae
small, reddish pinpoints best observed on tummy and butt < 1-2 mm in extravascular tissue
petechiae for dark skin
difficult to see, may be evident in the buccal mucosa of mouth or conjunctiva of eye
rash for dark skin
feel!! aka palpate
purpura
bleeding disorder caused by ecchymosis or petechiae
if a lesion blances and then refills, redness is r/t
dilated blood vessels
if the lesion does not blanch and remains discolors it’s r/t
subq or intradermal bleeding or nonvascular lesion
asymmetric lesion
unilateral distribution
confluent lesion
merges together
diffuse lesion
wide distribution
discrete lesion
separate from other lesions
symmetric lesion
bilateral distribution
zosteriform lesion
bandlike distribution along a dermatome area
increased localized temperature
seen with burns and local inflammation
increased generalized temperature
fever
carotenemia
yellow discoloration of skin, not eyes, most visible on palms and soles: veggies containing carotene can cause this (carrots, squash)
comedo
acne
cyst
sac containing fluid or semisolid material: caused by obstruction of duct or parasitic infection
hematoma
extravasation of blood: trauma and bleeding disorders
hirtuism
excess hair: abnormality of adrenal glands, decrease in estrogen
lichenification
thickening of skin: caused by excessive scratching rubbing or irritation
mole
nevus aka overgrowth of melanocytes
telangiectasia
visibly dilated, superficial, cutaneous small blood vessels, found on face and thighs: aging acne, alcoholism, liver failure, radiation, sun exposure
vitiligo
complete absence of melanin: autoimmune, thyroid disease
punch biopsy
use a punch instrument to obtain dermis and some fat for full thickness diagnostic purposes; place in Michel’s fixative not formalin
excisional biopsy
entire lesion removed with good cosmetic results, closed with sutures
incisional biopsy
wedge-shaped incision made, used when excisional or punch is not an option due to large specimen needed
shave biopsy
single-edged razor blade used to shave off superficial lesion, thin specimen
potassium hydroxide (KOH)
hair, scales, or nails examined for superficial fungal infection
Tzanck test (Wright’s and Giemsa’s stain)
fluid and cells from vesicles examined; used for herpes; sterile
fungi culture
scraping or swab of skin performed
bacteria culture
material obtained from intact pustules, bullae, or abcesses
virus culture
vesicle/bulla and exudate taken from base of lesion
mineral oil slides
checks for infestations, scrapings are placed on slide with mineral
immunofluorescent studies
skin tissue and serum examined due to some diseases having specific, abnormal antibody proteins
wood’s lamp (black light)
identifies pseudomonas organisms, fungal infections, and vitiligo
patch test
determines what patient is allergic to by applying potential allergen on back; instruct patient to return in 48-72 hrs to remove allergens and evaluation @ 96 hr
