BIO-168 Chapter 6
whitehead
a closed comedo
onychomycosis
a fungal nail infection causing a yellow discoloration
spoon nails
a nail malformation where the outer surface of the nails are concave rather than convex
urea
a nitrogenous waste produced from breakdown of amino acids
periderm
a protective layer of squamous epithelium
comedo acne
a sebaceous gland plugged with sebum
vernix caseosa
a waterproof protective covering over the skin of the fetus
albinism
absence of pigment in the skin, hair, and eyes; melanocytes cannot produce pigment
calcitrol
active form of vitamin D
3rd degree burn
all layers typically destroyed; cannot retain water, dehydration is a major concern
elastic fibers
allow stretch and recoil
escharotomy
an incision made in the dermis to lessen constriction
sebum
an oily mixture of lipids
blackhead
an open comedo
nevus
an overgrowth of melanocytes; aka a mole
melanin
any of the dark brown-black pigments or yellow-red pigments that occur in the skin, hair, and retina.
hyponychium
area of thickened epithelium underlying the free edge of the nail
alopecia areata
autoimmune disorder where the body attacks the hair follicles, leading to spot baldness
male pattern baldness
causes loss of hair first from only the crown region of the scalp rather than uniformly
apocrine glands
coiled, tubular glands that secrete out of hair follicles in the axillae, around the nipples, in the pubic region, and in the anal region
hair papilla
composed of a small amount of connective tissue containing tiny blood vessels and nerves
medulla
composed of loosely arranged cells and contains soft, flexible keratin; not found in all hair types
dermis
connective tissue layer of the skin beneath the epidermis; contains primarily collagen fibers
hair bulb
consists of epithelial cells and is a swelling at the base where the hair originates in the dermis
stratum basale
deepest epidermal layer made of a single row of cuboidal to low columnar cells; attached to an underlying basement membrane
subcutaneous layer
deepest layer of the skin but not included in the integumentary system; composed of areolar and adipose connective tissue
connective tissue root sheath
derived from the dermis and surrounding the epithelial root sheath
epithelial tissue root sheath
derived from the epidermis
free edge
distal, light-colored region at which the nail ends
subcutaneous layer
drugs are often injected into which later?
mesenchyme
embryonic connective tissue
2nd degree burn
epidermal and upper dermal; blistered and painful skin
1st degree burn
epidermal damage; redness, pain, and slight edema; aka superficial burn
hirsutism
excessive terminal hair growth
vellus hair
fine, nonpigmented hair covering most of the fetal body.
lanugo hair
fine, soft, unpigmented fetal hair; usually replaced by vellus hair at birth
fibrosis
formation of fibrous connective tissue as a repair or reactive process.
hair
found almost everywhere on the body minus the palms, soles, lips, and portions of external genitalia
cryosurgery
freezing tissue to destroy cells
acne
general term for plugged sebaceous ducts
stratum granulosum
granular layer made of 3-5 layers of keratinocytes
diffuse hair loss
hair is shed from all parts of the scalp
nail plate
hard, visible part of the nail made up of the free edge, nail body, and nail root
friction ridges
help increase friction on contact
epidermal dendritic cells
immune cells that help fight infection in the epidermis; aka Langerhans cells
collagen fibers
impart tensile strength
what two cell types make up the stratum spinosum?
keratinocytes and Langerhans cells
cyst
large, fluid filled nodule
freckles
localized areas of increased melanocyte activity
terminal hair
long, coarse, pigmented hair found on the scalp, legs, arms, and bodies of males and females.
desmosomes
membrane junctions
mammary glands
modified apocrine sweat glands that can produce milk in females
ceruminous glands
modified sweat glands, located in external ear canal, secretes cerumen (earwax)
merocrine glands
most numerous and widely distributed sweat glands; simple, coiled, tubular glands that secrete sweat directly onto skin surface
dendritic cells
motile cells in the dermis that serve an immune function
brittle nails
nails prone to vertical splitting at the nail edge
epidermal derivatives
nails, hair, exocrine glands
vasoconstriction
narrowing of the blood vessels, which decreases blood flow; conserves heat
hair follicle
oblique tube surrounding the hair root, extending into the dermis and sometimes the subcutaneous layer
yellow nail syndrome
occurs when nail growth and thickening slows
ingrown nails
occurs when the nail edge digs into the skin around it
sweat pore
opening of a sweat duct
hair cuticle
outermost layer that coats the hair
hemoglobin
oxygen-binding protein found in red blood cells
pustule
papules containing pus
melanocytes
pigment-producing cell in the basal layer of the epidermis.
hair buds
pockets of cells that become hair follicles
shaft
portion of hair extending beyond the skin surface
keratinization
process during which keratinocytes fill with the protein keratin.
absorption
process of moving substances, such as products of digestion, into the blood or lymph.
holocrine glands
produce sebum that is discharged from the hair follicle onto the hair itself
eumelanin
produces brown to black pigments
pheomelanin
produces yellow to red pigments
secretion
production and release of active substances by a cell or gland
dermal papillae
projections of dermis that cause epidermal ridges and server as tactile receptors
keratin
protein that strengthens the epidermis, hair, and nails
nail root
proximal part embedded in the skin
cavernous hemangioma
reddish-blue, irregularly shaped, solid and spongy mass of blood vessels
debridement
removing dead tissue and debris from a wound
dermabrasion
sanding down tattooed skin
tactile cells
sensory touch receptors; aka Merkel cells
cortex
several layers of flattened cells surrounding medulla
nodule
similar to papules but go deeper within the skin, usually rupturing hair follicle walls
nail folds
skin folds that overlap border of nail
nail bed
skin underlying the nail plate
papule
small, solid skin elevation; do not contain pus
capillary hemangioma
strawberry birthmark; pink or red birthmark
striae
stretch marks
hair matrix
structure adjacent to the hair papilla in the hair bulb where special keratinization occurs
papillary layer
superficial layer of the dermis; made of loose, areolar connective tissue
lines of cleavage
tension lines that indicate the direction of collagen fiber bundlese
sensory reception
the ability of tactile sensory receptors to detect stimuli
nail matrix
the actively growing part of the nail
reticular layer
the deeper layer of the dermis composed of dense irregular connective tissue
anagen phase
the first and longest phase of hair growth where it is actively growing; can last from 18 weeks to 7 years
lunula
the half-moon-shaped, whitish area at the base of a nail
ectoderm and mesoderm
the integumentary system is derived from what two germ layers?
keratinocytes
the most abundant cell type in the epidermis and found throughout all epidermal layers; produce keratin.
cuticle
the narrow band of epidermis extending from the nail wall onto the nail surface; aka eponychium
mesoderm
the origin of the dermis is which layer?
ectoderm
the origin of the epidermis is which layer?
regeneration
the replacement of dead or damaged cells by the same type of cell as before
catagen phase
the second phase of hair growth where cell division ceases and the follicle undergoes involution; lasts about 3 to 4 weeks
cytokeratins
the specific type of keratin cells within keratinocytes
stratum spinosum
the spiny layer
dermatoglyphics
the study of the pattern of friction ridges
telogen phase
the third and final hair growth phase where the hair is usually shed; 3 or 4 months after this phase, the follicle enters the anagen phase again
stratum corneum
the top, hornlike layer consisting of 20-30 layers of dead keratinized cells
granulation tissue
the vascular connective tissue that normally forms during the healing of a wound
arrector pili
thin ribbons of smooth muscle extending from the hair follicle to the dermal papillae; produces goosebumps
stratum lucidum
thin, translucent layer of dead cells found only in thick skin made of 2-3 keratinocyte layers
nail pitting
tiny depressions or shallow holes appearing in the nail body
epidermis
top layer of keratinized stratified squamous epithelium of the integumentary system
sweat gland duct
transports the secretion to the surface of the epidermis or hair follicle
hemangioma
tumor consisting of blood vessels
rule of nines
used to estimate surface area of burn for determining fluid replacement
Beau's lines
visible depressions running across the width of the natural nail plate
nail body
visible, darker part of the nail
what vitamin is beta-carotene converted into?
vitamin A
cholecalciferol
vitamin D3 in response to keratinocytes being exposed to UV light
cerumen
waterproof earwax
(1) protection (2) water balance (3) vitamin D synthesis (4) secretion (5) absorption (6) temperature regulation (7) immune assistance (8) sensory perception
what are the 8 functions of the integumentary system?
(1) stratum corneum (2) stratum lucidum (3) stratum spinosum (4) stratum granulosum (5) stratum basale
what are the five layers of epidermis (top to bottom?)
(1) protection (2) heat retention (3) sensory reception (4) visual identification
what are the four functions of hair?
holocrine glands
what are the sebaceous glands known as?
(1) anagen (2) catagen (3) telogen
what are the three stages of the hair growth cycle?
merocrine and apocrine
what are the two different types of sweat glands?
connective tissue root sheath and epithelial tissue root sheath
what are the two layers within the hair follicle?
epidermis and dermis
what are the two layers within the integumentary system?
a papillary layer and a reticular layer
what are the two major regions of the dermis?
sweat and sebaceous glands
what are the two most common exocrine glands?
ceruminous glands and mammary glands
what are the two specialized integument glands?
3rd
what degree burn is considered a full-thickness burn?
1st and 2nd
what degree burns are considered a partial-thickness burn?
asymmetry, border, color, diameter, evolving
what is the ABCDE rule?
integument
what is the body's largest organ?
3-5 days
what is the healing time for a 1st degree burn?
2-4 weeks
what is the healing time for a 2nd degree burn?
basal cell carcinoma
what is the least dangerous type of skin cancer?
thermoregulation
what is the major function of merocrine glands?
skin cancer
what is the most common type of cancer?
basal cell carcinoma
what is the most common type of skin cancer?
malignant melanoma
what is the most deadly type of skin cancer?
immerse burn in cool water or apply cool, wet compress
what is the treatment for a 1st degree burn?
immerse burn in cool water or apply cool, wet compress; careful not to break blisters; elevate limbs
what is the treatment for a 2nd degree burn?
hospitalization; skin grafts usually necessary
what is the treatment for a 3rd degree burn?
subcutaneous layer
what layer is below the dermis?
keratinocytes, melanocytes, and tactile cells
what three cells make up the stratum basale?
subcutaneous fat
when adipose tissue predominates areolar tissue in the subcutaneous layer in the body
nail clubbing
when the nail enlarges or clubs at the edges and they grow curved around the tip; indicative of hypoxia
stratum basale
where does basal cell carcinoma originate?
melanocytes
where does malignant melanoma originate?
stratum spinosum
where does squamous cell carcinoma originate?
palms and soles
where is thick skin found?
stratum lucidum
which epidermal layer is found only in thick skin?
stratum granulosum
which layer does keratinization begin?
vasodilation
widening of the blood vessels, which increases blood flow; releases heat
carotene
yellow-orange pigment
root
zone of hair from bulb to skin surface