Chapter 6; The Integumentary System Flashcards
dermatology
branch of medicine specializing in the care and treatment of the skin
integumentary system
consists of the skin, hair, nails, and their associated glands
skin (integument)
the body’s largest and heaviest organ
epidermis
outer layer of skin (stratified squamous epithelium)
dermis
deeper connective tissue layer
hypodermis
another layer of connective tissue below the dermis
thick skin
covers the palms, soles, and corresponding surfaces of the fingers and toes
stratum corneum
very thick surface layer of dead cells
thin skin
an epidermis about 0.1 mm thick, with a thin stratum corneum. It possesses hair follicles, sebaceous glands, and sweat glands
keratin
protein that is packed into the epidermal cells
acid mantle
protective acidic film
epidermis
a keratinized stratified squamous epithelium
stem cells
undifferentiated cell that divide and give rise to the keratinocytes
stratum basale
deepest layer of epidermis
keratinocytes
great majority of epidermal cells
melanocytes
occur only in stratum basale, amid the stem cells and deepest keratinocytes
melanin
they synthesize the brown to black pigment
melanosomes
melanin-containing fragments
tactile cells
receptors for touch
tactile disc
the tactile cell and its nerve fiber
dendritic cells
immune cells that originate in the bone marrow but migrate to the epidermis and epithelia of the oral cavity, esophagus, and vagina
stratum basale
consists mainly of a single layer of cuboidal to low columnar stem cells and keratinocytes resting on the basement membrane
stratum spinosum
consists of several layers of keratinocytes
artifact
artificial appearance
stratum granulosum
consists of three to five layers of flat keratinocytes-more than thick skin than in thin skin
keratohyalin granules
layer of keratinocytes that are coarse, dark-staining
stratum lucidum
a thin zone superficial to the stratum granulosum
eleidin
clear protein that is densed in keratinocytes
stratum corneum
consists of up to 30 layers of dead, scaly, keratinized cells that form a durable surface layer
filaggrin
a protein that is released by keratohyalin granules
envelope proteins
tough layer that is beneath the plasma membrane
exfoliate
the process of dead keratinocytes that flake off from the epidermal surface
dander
the flakes that come off
dandruff
clumps of dander stuck together by sebum (oil)
dermal papillae
the upward waves are fingerlike extensions of the dermis
epidermal ridges
downward epidermal waves between the papillae
friction ridges
wavy boundary that forms and produces fingerprints
papillary layer
a thin zone of areolar tissue in and near the dermal papillae
reticular layer
consists of dense irregular connective tissue
striae
stretch marks
subcutaneous fat
hypodermis composed predominantly of adipose tissue
eumelanin
brownish black
pheomelanin
reddish yellow sulfur-containing pigment
hemoglobin
the red pigment of blood, imparts reddish to pinkish hues as blood vessels show through the skin
carotene
a yellow pigment acquired from egg yolks and yellow and orange vegetables
cyanosis
blueness of the skin resulting from a deficiency of oxygen in the circulating blood
erythema
abnormal redness of the skin
pallor
pale or ashen color that occurs when there is so little blood flow through the skin that the white of the dermal collagen shows through
albinism
a genetic lack of melanin that usually results in milky white hair and skin, and blue-gray eyes
jaundice
yellowing of the skin and whites of the eyes resulting from high levels of bilirubin in the blood
hematoma
bruise that is a mass of clotted blood showing through the skin
friction ridges
the markings on the fingerprints that leave distinctive oily fingerprints on surfaces we touch
lamellar corpuscles
improves one’s grasp and aid in the manipulation of small and rough-surfaced objects
flexion lines (flexion creases)
the lines on the flexor surfaces of the digits, palms, wrist, elbows, and other places
freckles
flat melanized patches that vary with heredity and exposure to the sun
mole (nevus)
an elevated patch of melanized skin
hemangiomas
patches of skin discolored by benign tumors of the blood capillaries
capillary hemangiomas (strawberry birthmarks)
bright red to deep purple and develop small capillary-dense elevations that give them a strawberry-like appearance
cavernous hemangioma
flatter and duller in color
port-wine stains
flat and pinkish to dark purple in color
accessory organs (appendages)
hair, nail, and sebaceous glands
soft keratin
makes up the stratum corneum
hard keratin
makes up the hair and nails
pilus
hair
hair follicle
a slender filament of keratinized cells that grows from an oblique tube in the skin
lanugo
fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development
vellus hair
fine, pale hair
terminal hair
longer, coarser, and usually more heavily pigmented
shaft
the portion of a hair above the skin
root
all of the stuff beneath the surface
bulb
dilation of the hair
dermal papilla
provides the hair with its sole source of nutrition
hair matrix
hair’s growth center
medulla
a core of loosely arranged cells and air spaces
cortex
constitutes most of the bulk of the hair
cuticle
composed of multiple layers of very thin, scaly cells that overlap each other with their free edges directed upward
epithelial root sheath
an extension of the epidermis, consists of stratified squamous epithelium and lies immediately adjacent to the hair root
connective tissue root sheath
derived from the dermis and composed of collagenous connective tissue, surrounds the epithelial sheath and is somewhat denser than the adjacent dermis
bulge
a source of stem cells for follicle growth
hair receptors
nerve fibers that entwine each follicle and respond to hair movements
piloerector muscle (pilomotor muscle or arrector pili)
a bundle of smooth muscle cells extending from dermal collagen fibers to the connective tissue root sheath of the follicle
hair cycle
3 developmental stages
anagen
stem cells from the bulge in the follicle multiply and travel downward, pushing the dermal papilla deeper into the skin and forming the epithelial root sheath
club hair
hair left from the previous cycle
catagen
mitosis in the hair matrix ceases and sheath cells below the bulge die
telogen
when the papilla reaches the bulge, the hair goes into a resting period
alopecia
thinning of the hair, or baldness
pattern baldness
the condition in which hair is lost unevenly across the scalp rather than thinning uniformly
sex-influenced traits
when an allele is dominant in one sex and recessive in the other
hirsutism
excessive or undesirable hairiness in already that are not usually hairy
guard hairs (vibrissae)
guard the nostrils and ear canals and prevent foreign particles from entering easily
nail plate
the hard part of the nail
free edge
the overhanging tip of the finger or toe
nail body
the visible attached part of the nail
nail root
extends proximally under the overlying skin
nail fold
rised skin that is above the nail
nail groove
separated the margin of the nail plate
nail bed
skin underlying the nail plate
hyponychium
its epidermis of the nail
nail matrix
located at the proximal end of the nail, the stratum basal thickens into a growth zone
lunule
opaque white crescent on the nail
cuticle (eponychium)
dead skin from the nail
clubbed
swollen fingertips
sweat glands (sudoriferous glands)
apocrine and merocrine sweat glands
apocrine sweat glands
occur in the groin, anal region, axilla, and areola, and in mature males, in the beard area
sex pheromones
chemicals that exert subtle effects on the sexual behavior and physiology of other people
bromhidrosis
disagreeable body odor
merocrine (eccrine) sweat glands
widely distributed over the entire body, but are especially abundant on the palms, soles, and forehead
myoepithelial cells
found amid the secretory cells at the deep end of the gland
acid mantle
inhibits bacterial growth on the skin
insensible perspiration
perspiration evaporates about as fast as it is produced
diaphoresis
excessive sweating
cutaneous transpiration
a significant amount is also lost by water simply diffusing between the keratinocytes and evaporating from the skin surface
sebaceous glands
produces an oily secretion called sebum
sebum
an oily secretion that are flask-shaped with short ducts that usually open into a hair follicle
ceruminous glands
modified apocrine glands found only in the external ear canal
cerumen
earwax
mammary glands
milk-producing glands that develop within the female breast during pregnancy and lactation
mammae
breasts
mammary ridges (milk lines)
mammary glands form along lines
polythelia
when someone develops additional nipples or mammae along the milk line
lesions
zones of tissue injury
basal cell carcinoma
most common type of skin cancer, least deadly because it seldom metastasizes, but if neglected, it can severely disfigure the face
squamous cell carcinoma
arises from keratinocytes of the stratum spinosum
melanoma
skin cancer that arises from the melanocytes
burns
usually caused by fires, kitchen spills, or excessively hot bath water, but they also can be causes by sunlight, ionizing radiation, strong acids and bases, or electrical shock
eschar
burned, dead tissue
first-degree burns
involve only the epidermis and are marked by redness, slight edema, and pain
second-degree burns
involve the epidermis and part of the dermis but leave at least some of the dermis intact
partial-thickness burns
another name for first and second degree burns
third-degree burns
epidermis, all of the dermis, and often some deeper tissues are destroyed
fourth-degree burns
down to the bone
debridement
removal of eschar
acne
inflammation of the sebaceous glands
dermatitis
any inflammation of the skin caused by exposure to toxic foliage
eczema
itchy, red “weeping” skin lesions caused by an allergy
psoriasis
recurring, reddened plaques covered with silvery scale
rosacea
a red rashlike area marked by fine networks of dilated blood vessels
seborrheic dermatitis
recurring patches of scaly white or yellowish inflammation often on the head, face, chest, and back
tinea
any fungal infection of the skin, wormlike growth pattern sometimes exhibited
