| Term | Definition |
|
epidermis |
the outer layer of skin, is thin but tough, and cells are bound tightly together into sheets that form a rugged protective barrier, it consisted of many stratified layers |
|
stratum germinativum |
the inner basal cell layer of the epidermis that forms new skin cells. made up of keratin, the fibrous protein, melanin is interspersed along this layer |
|
stratum corneum |
the outer horny layer of the epidermis formed by the migrated, flattened cells of the basal layer. this layer consists of dead keratinized cells that are interwoven and closely packed. these cells are constantly being shed and are completely replaced with new cells from below |
|
dermis |
the inner supportive layer of the skin that consists mostly of connective tissue or collagen (the tough fibrous protein that enables the skin to resist tearing) as well as resilient elastic tissue that allows the skin to stretch with body movements. contains the nerves, sensory receptors, blood vessels, lymphatics, hair follicles, sebaceous glands, and sweat glands. |
|
subcutaneous layer |
adipose tissue; stores fat for energy, provides insulation for temperature control, and aids in protection by its cushoning effect, provides mobility over underlying structures |
|
shaft |
the portion of threads of keratin that are visible |
|
root |
protion of hair that is below the surface, embedded in the follicle |
|
bulb matrix |
located in the expanded areas where the new cells are produced at a high rate |
|
vellus hair |
fine, faint hair that covers most of the body, except the palms, soles, dorsa of distal fingers, umbilicus, glands penis, and inside the labia |
|
terminal hair |
darker, thicker hair that grows on the scalp and eyebrows and, after puberty, on the acillae, pubic area, and the face and chest in male |
|
sebum |
a protective liquid substance that is secreted through the skin and hair and forms an emulsion with water that retards water loss from the skin. this is secreted from glands that are located on the palms and the soles. |
|
eccrine glands |
coiled tubules that open directly onto the skin surface and produce a dilute saline solution called sweat. this helps reduce body temperature |
|
apocrine glands |
the producers of a thick, milky secretion that opens directly into the hair follicles. located in the axillae, anogenital area, nipple, and naval....highly vestigal in humans. Become active during puberty, and are stimulated with emotion and sexual stimulation |
|
lanula |
the white opaque semilunar area at the proximal end of the nail. |
|
nail matrix |
lies beneath the lanula and is the location of new keratinized cells. |
|
nail bed |
lies beneath the nail and is the site of highly vascular epithelial cells. |
|
lanugo |
fine downy hair of the newborn |
|
vernix caseosa |
the thick, cheesy substance present at birth that is made up of sebum and shed epithelial cells |
|
linea nigra |
an increased pigment in the areolae and nipples, vulva, and sometimes in the midline of the abdoment because of the change in hormone levels in pregnant women |
|
chloasma |
increased pigmentation in the face because of a change in hormone levels in pregnant women |
|
striae gravidarum |
marks resulting from connective tissues increases fragility in pregnant women in the skin of the abdomen, breasts, or thighs. |
|
senile purpura |
a dark red discolored area found in elderly because of their decreasing vascularity and increasing fragility of skin |
|
pruritus |
itching |
|
vitilgo |
complete absennce of melanin pigment in patchy areas of white or light skin on the face, neck, hands, feet, body folds, and around orifices |
|
ephilides |
freckles. a small, flat macule of brown pigment that occur on sun-exposed skin |
|
nevus |
mole. a proliferation of melanocytes, tan or brown color, flat or raised. symmetrical, small, smooth borders, uniform pigmentation |
|
diaphoresis |
profuse perspiration |
|
mongolian spot |
a common variation of hyperpigmentation in black, asian, nnative american, and hispanis newborns. a blue/black/purple macular area at the sacrum or buttocks, sometimes occurs on the abdomen, thighs, shoulders, or arms |
|
cafe au lait spot |
a large round or oval patch of light-brown pigmentation, which is usually present at birth |
|
Harlequin color change |
when the baby is in a side-laying position the lower half of the body turns red and the upper half blanches with a distinct demarcation line down the midline |
|
erythema toxicum |
a common rash that appears in the first 3-4 days of life. sometimes aka the "flea bite or newborn rash |
|
acrocyanosis |
a bluish color around thelips, hands and fingernails or feet and toenails in newborns. it may last a few hours and disappear with warming |
|
cutis marmorata |
a reticulated red or blue pattern over the skin found in infants' trunk or extremeties in response to cooler room temperatures |
|
physiological jaundice |
a common variation in about half of newborns that causes yellowing of the skin, sclera, and mucus membranes. develops after the 3-4th day of life because of the increased numbers of RBC that hemolyze following birth and are coverted into bilirubin |
|
carotenemia |
a yellow-orange color in light-skinned persons but does not result in the sclera or mucous membranes. it results from ingesting large amounts of carotene-rich foods, and fades to normal color within 2 wks of withdrawing carotene-rich foods from the diet. |
|
milia |
tiny, white papules on the cheeks, forhead, and across the nose and chin due to sebum that occludes the opening of the follicles. they resolve spontaneously within a few weeks |
|
storkbite |
aka salmon patch, a flat, irregularly shaped red or pink patch found on the forehead, eyelid, or upper lid, but most commonly at the back of neck. present at birth and fades during the first year. |
|
acne |
caused by increased sebaceous gland activity in adolescence, can include milder open/closed comedones (white and black heads), or the more severe papules, postules and nodules. these lesions appear on the face, chest, back, shoulders |
|
striae |
jagged linear "stretch marks" of silver to pink color that appear during the second trimester on the abdomen, breasts, and sometimes thighs. they fade after pregnancy but do not disappear. |
|
vascular spiders |
lesions occuring in 2/3 of pregnancies in that have tiny red centers with radiating branches and occur on the face, neck, upper chest, and arms |
|
keratoses |
lesions that are raised, thickened aras of pigmentation that look crusted, scaly, and warty. there are many different forms, caused by/no relation to the amount of sun exposure, malignant or benign. common in older adults |
|
acrochordons |
overgrowths of normal skin that form a stalk and are polyplike. aka skin tags commonly occuring in older adults |
|
sebacceous hyperplasia |
raised yellow papules that have a central dpression. common on oler men's foreheads, nose, or cheeks |