A&P chapter 5 section 5.1
circulation
nail beds and gums color provide information about what?
2 (22 square feet)
In adults how many square meters is skin?
2 3 4 1
1. cells are sloughed off 2. cells form in stratum basale 3. rise to surface 4. become keratinized what is the correct order ? ( this process takes 4-6 weeks)
melanocytes
8% of epidermis cells are this and it develops from the ectoderm of a developing embryo and produces the pigment melanin?
keratinocytes
90% of epidermal cells are what cell?
age spots
As a person ages what blemish may develop in skin
skin
Because of its visibility what reflects our emotions (frowning, blushing) and some aspects of normal physiology like sweating?
amount of heat loss (thermoregulation)
Blood vessels increase and more blood flows through them which increases what?
no and because its avascular
Can you bleed if you cut the epidermis? and why?
A
Carotene is a precursor of what vitamin
more flattened
Cell in the more superficial layer of the stratum spinosum become what shape?
thornlike spines
Cells of the stratum spinosum shrink and pulled apart when prepared for microscope examination, except where membranes join at desmosomes, so they appear to be covered with what?
Homeostasic imbalance
Changes in skin color may indicate what in the body? example (bluish skin color is associated with hypoxia an oxygen deficiency in tissue, is a sign of heart failure).
ability to stretch (around joints and in pregnancy and obesity)
Combination of collagen and elastic fibers in reticular region provides the skin with strength and extensibility. What does extensibility mean?
skin
Conditions like warts, age spots, and pimples involves only what organ?
melanin in epidermis
Dark- skinned individuals have a large amount of what where? (yellow to reddish-brown)
UV radiation
Darker and more melanin helps protect the skin from what?
keratohyalin
Darkly staining granules of a protein that assembles keratin intermediate filaments into keratin is called what? (stratum granulosum)
hair root plexus
Dendrites of neurons form what which is sensitive to touch and generates nerve impulses if hair shafts are moved?
flattened process of a nerve cell
Describe the tactile disc (merkel disc) structure
amount of pigment the melanocytes prduce and transfer to keratinocytes.
Differences in skin color is due to what?
no
Does water enter the body through the skin?
growth epidermis (rate of cell division in stratum basale)
EGF or epidermal growth factor (hormone like protein) plays a role in what?
strong bond
Epidermal ridges creates what between the epidermis and dermis in a region of high mechanical strength
The basement membrane positioned between the epidermis and the dermis
Hemidesmosomes in the straum basale that are attached to keratin intermediate filaments binds keratinocytes to what?
milky or yelowish
How does apocrine sweat appear? (in color)
2-6 years
How long is hair in growth stage
10-15 mins twice a week
How much UV light (sun) is required for Vitamin D syntheisis
hair follicele
In apocrine glands where does the excretory duct open up to?
strata or layers
In most regions of the body the epidermis has four what?
melanin
In the epidermis what is a yellow red or brown-black pigment that contributes to skin color and absorbs damaging UV light?
keratohyalin
Intermediate filaments are assembled into keratin in the stratum granulosum what is this called ?
yes
Is the number of melanocytes the same in all people?
males
Is there more terminal hair on males or females?
keratin
Keratinocytes cells are arranged in four or five layers and produce what protein?
stem cells in the stratum basal
Kertynocytes in the stratum spinosum, are produced by what and where?
desmosomes
Keratin intermediate filaments attach to what junctions in the stratum basale?
organelles in the cells are regressing
Keratin intermediate filaments become more apparent in stratum granulosum and layers above it of epidermis because what?
resting stage
Last stage of hair growth ?
the basal epithelial stem cells to divide and the keratinocytes to grow and develop
Molecules from the small blood capillaries in the dermal papillae that diffuse to the cells in the stratum basale allows what?
Vitamin D
Most cells in the immune system have what vitamin receptors
hair
The forms of melanin yellow to red and brown to black is more apparent where?
inner medulla
The three concetric layers of cells are the medulla, cortex, and cuticle of the hair, what is lacking in thinner hair?
palms and soles
Sebaceous glands are not present where?
epidermis
Several distict layers of keratinocytes in various stages of development form what?
protective features
Skin can ward off damage from the environment (microbes, sunlight, trauma and pullution) because of what?
heels
Skin on average is 1-2 mm thick but ranges in thickness from .5 mm on eyelids and 4.0 mm where?
stem cells
Some cells in the strtum basale layer undergo cell division to continually produce new keratinocytes. What cell is this?
papillary surface of the dermis
What forms the epidermal ridges?
forming new cells
Stratum basal is also knows as the stratum germinativum to indicate its role of what?
pore
Sudoferous glands are in the deep dermis and the excretory duct projects through to the epidermis and ends as what at the surface of the epidermis?
palms and soles
Sweat first forms on forehead and scalp and lastly where?
true
Sweat secreted from apocrine sweat glands are odorless? T or F
puberty
Terminal hair replace vellus hairs (peach fuzz) in what stage of life?
stratum basale
The deepest layer of the epidermis is called what?
cuticle
The eponychium is also known as
cells in stratum corneum (membrane-enclosed packages of keratin)
The final product of differentiation process of keratinocytes is what?
increases the source of nutrition for the epidermis. (blood vessels from the papillary surface is increased)
The increase surface contact between the dermis and epidermis by the dermal papillae does what for the dermis?
temperature
The integumentary system helps maintain a constant body what?
epithelial root sheath
The internal and external root sheath are reffered to as what?
basal layer
The keratinocytes of the stratum spinosum produce coarser bundles of keratin in intermediate filaments than those of what layer?
Acts as a water-repellent sealant (retarding loss and entry of water and entry of foreign matrial) Deposited between cells of stratum granulosum, stratum lucidum, and stratum corneum)
The lipid rich secretion from keratinocytes lamellar granules have what function? and where are they deposited?
keratinocytes
The nuclei of what cell in the stratum basale are large, with their cytoplam containtaing many ribosomes, a small golgi complex, few mitochondria and some rough ER
directly onto the surface of the skin
The secreting portion of a sebaceous gland lies in the dermis and opens into the neck of a hair follicle except in lips, glans penis, labia minora, and tarsal glands of eyelids where the secreting portion opens up to where?
vitamin D
The skin synthesizes what vitamin?
keratinocytes
The stratum basale is composed of a SINGLE row of cuboidal or columnar what cells?
8-10
The stratum spinosum consists of numerous keratinocytes arranged in how many layers?
finger tip
The thickened stratum corneum region called hyponychium secured the nail to what?
where exposure to friction is greatest (fingertips, palms, and soles)
Thick skin is located where?
pigments needed for vision
Vitamin A into carotene is needed to synthesize what
skin
What acts as a blood resevoir?
keratin intermediate filaments inserted into desmosomes
What adds strength and flexibility to the skin in the stratum spinosum?
fibers
What anchors the skin to the subcutaneous layer, which in turn attaches to underlying fascia (connective tissue around muscles and bones)
hormones secreted during puberty that cuases hair growth
What are androgens
The series of ridges and grooves (either straight or loops) on palms, fingers soles and toes
What are epidermal ridges that are formed by papillary surface? (what they look like)
chickenpox, cold sores, or measles
What are examples of normal skin eruptions or rashes that may reveal systematic infections or diseases of internal organs?
present in keratinocytes, release lipid-rich secretion
What are lamellar granules?
ceruminous glands
What are modified sweat glands in the external ear that produce waxy lubricating secretion called?
nails
What are plates of tightly packed, hard, dead, keratinized epidermal cells that form a solid covering over the dorsal surfases of the digintals?
eccrine sweat glands
What are simple, coiled tubular glands that are much more common than apocrine sweat glands?
increase surface area of epidermis which increases grip and number of corpuscles of touch which increase tactile sensitivity
What are some functions of epidermal regions?
keratinocytes, melanocytes, intraepidermal macrophages, and tactile epithelial cells
What are the four principal types of cells in the epidermis?
terminal hairs
What are the pigmented hairs that appear prior to birth after lanugo hair is shed? (in eyebrows and eyelashes and scalp hair)
nail body (visible portion of nail), nail root (burried in fold) and free edge (extends past distal end)
What are the three parts of the nail?
melanin, hemoglobin and carotene
What are the three pigments that impart a wide variety of colors to the skin?
hair root plexuses
What are the touch receptors associated with hair follicles called?
thin skin(hairy) thick skin(hairless)
What are the two major types of skin and which one is hairy or hairless?
intraepidermal macrophages (alert immune system to the presence of potentially harmful microbial invaders) and macrophages in the dermis (phagocytosis)
What are the two types of cells that that carry out protective functions that are immunological in nature
swating and adjusting the flow of blood in the dermis
What are the two ways the skin contributes to thermoregulation?
cells in stratum corneum
What are think flat plasma membrane enclosed keratin
skin
What body organ is the most easily inspected or more exposed to infection, disease and injury?
melanin
What causes the skins color to vary from pale yellow to reddish-brown to black?
intraepidermal macrophages
What cell type arise from red bone marrow and migrates to the epidermis? (is a small fraction of the epidermal cell)
intraepidermal macrophages, and projections of the melanocytes
What cells are also present in the stratum spinosum besides keratinocytes?
sebum
What coats the surface of hairs and helps keep them from drying and becoming brittle, prevents excessive evaporation of water from the skin, keeps skin soft and pliable, and inhibits the growth of some (but not all bacteria).
dermal papillae and epidermal ridges
What connection helps the epidermis and the dermis not separate with shearing forces?
molecules
What diffuses from the small blood capillaries in the dermal papillae to the cells of the stratum basale
tough protein keratin
What do keratin intermediate filaments form in the more superficial epidermal layer?
enzymatic activity which increases amount and darkness of melanin production
What does UV light increase within melanosomes
injury, suns rays and heat loss
What does hair on your head protect you from? (3 things)
keratin intermediate filaments
What does the cytoskeleton within keratinocytes of the stratum basale include
stratum granulosum
What does the epidermis of the nail lack?
water ammonia urea salts and CO2
What does the integumentary excrete?
tightly joins them to one another
What does the keratin intermediate filaments in desmosomes in the stratum spinosum do to cells?
tactile epithelial cells
What epidermis cell type are the least numerous and is located in the deepest layer of the epidermis?
tactile epithelial cell
What epidermis cell type contacts the flattened process of a sensory neuron (nerve cell) called tactile disc
intraepidermal macrophages
What epidermis cell type participates in immune responeses mounted against microbes that invade the skin, and are usually damaged by UV light?
phemelanin, and eumelanin (brown to black)
What form of melanin is pale yellow to red and what form is brown to black?
apocrine sweat glands
What gland is found in the axilla (armpit), groin, areolae (around nipples), and bearded reagions of the face
sudoriferous glands (sweat glands)
What gland secretes sweat or perspiration into hair or skin through pores?
sebaceous glands (oil glands)
What glands are simple branched acinar glands that are usually connected to hair follicles?
regression stage
What happens after growth stage when cells of the matrix stop dividing (hair follicle shrinks)? (what stage)
become keratinized and die
What happens to cells as they are being pushed upward
old hair root falls out
What happens to hair after resting stage
physiological or emotional stress causing "goose bumps"
What happens when arrector pili contract
dermal papillae
What increases the surface contact between the dermis and epidermis?
tension lines
What indicates the predominant direction of underlying collagen fibers? (if surgical incision runs through the parallel of this line aka the collagen fibers it will heal with only a fine scar)
bundles of keratin intermediate filaments
What inserts into the desmosomes in each of the spinelike projections of the stratum spinosum
nevus or mole
What is a round, flat, or raised area that represents a benign localized overgrowth of melanocytes that usually develops in adolescence or childhood
acne
What is an inflammation of a sebaceous gland that usually begins at puberty when the sebaceous glands are stimulated by androgens?
male-pattern baldness
What is androgenic alopecia
active form of Vitamin D
What is calcitriol (aids absorption of calcium
erythema
What is caused by redness of the skin, engorgement of capillaries in dermis by injury allergy heat infection or inflammation?
stretch marks (striae)
What is caused when there is internal scarring due to internal damage to the collagenous vascular part of dermis? (collegan fibers are disrupted and small dermal blood vessels rupture)
hair
What is composed of columns of dead keratinized epidermal cells bonded together by extracellular proteins?
cells stop migrating to each other in wound healing
What is contact inhibitation
subcutaneous layer
What is deep to the dermis and not part of the skin?
jaundice
What is due to the buildup of yellow pigment bilirubin?
When eccrine and (apocrine) glands release sweat in response to an emotional stress such as fear or embarrassment
What is emotional sweating? (or cold sweat)
epidermal ridge pattern
What is in part genetically determined and is unique for each individual? even twins
hirsutism
What is it called when a tumor produces an excessive amount of adrogens (masculining sex hormones) causing an excessive amount of body hair
impacted cerumen
What is it called when an abnomally large amount of cerumen accumulates in ear, not allowing sound waves from reaching eardrum?
Cystic acne
What is it called when an infection causes a cyst or sac of connective tissue cells to form which destroys and displaces epidermal cells?
melanocytes (melanin producing cells)
What is more plentiful in the epidermis of penis, nipples, around nipples, face and limbs
pallor
What is paleness of skin called that occurs in shock or anemia?
alopecia
What is partial or complete lack of hair?
lamellar granules
What is produced by keratinocytes that releases a water-repellent sealent that decreases water entry and loss and inhibits the entry of foreign materials?
sweat
What is produced by the body and is primarily water, ions (Na Cl), urea, uric acid, ammonia, amino acids, glucose, and lactic acid
lipids
What is released by lamellar granules to inhibit evaporation of water (and entrance of it)
insensible perspiration
What is sweat that evaporates from the skin before it is perceived as moisture called?
sensible perspiration
What is sweat that is excreted in larger amounts and is seen as moisture on the skin called?
melanin in malanocytes
What is synthesized from the amino acid tyrosine in the presence of an enzyme (tyrosinase) in the organelle melanosome
hair bulb
What is the base of each hair follicle and its surrounding dermal root sheath is an onion shaped structure called what?
cerumen (ear wax)
What is the combined secretion of ceruminous and sebaceous glands that is yellowish called?
virtiligo
What is the condition of partial or complete loss of melanocytes from patches of the skin? Antibodies attack the mekanocytes
dermis
What is the deeper, thicker part of skin?
lanugo
What is the fine nonpigmented downy hair that develops at about 12 weeks after fertilization called?
retards the growth of some microbes
What is the function of acidic sweat? (perspiration)
barrier that impedes entrance of foreign bodies, insects, water and prevents bacteria and fungi from entering cells
What is the function of cerumen and hairs in ear
provides additional level of toughness in thick skin
What is the function of the stratum lucidum (4-6 layers of flattened clear, dead keratinocytes that contain large amounts of keratin and thickened plasma membrane only found in thick thick skin)
thermoregualtion
What is the homeostatic regulation of body temperature called?
skin, hair, oil and sweat glands, nails and sensory receptors
What is the integumentary system composed of?
help regulate body temperature through evaporation
What is the main function of eccrine sweat glands?
dermatology
What is the medical specialty that deals with the structure, function, and disorders of the integumentary system?
sebum
What is the oily substance sebaceous glands secrete that is a mixture of triglycerides, cholesterol, proteins, and inorganic salts?
fibrosis
What is the process of scar tissue formation called?
thermoregulatory sweating
What is the role of eccrine sweat glands helping the body acieve thermoregulation called? (heat energy leaves body when you sweat)
help other cells of the immune system recognize an invading microbe and destroy it
What is the role of intraepidermal macrophages in the immune response?
vellus hairs (produced before birth)
What is the short fine pale hairs that cover most of body except eyelashes scalp and eyebrows called? (peach fuzz)
nail bed
What is the skin below the nail body (plate) called?
dermatoglyphics
What is the study of a pattern of epidermal ridges called?
epidermis
What is the superficial, thinner portion of skin called?
skin grafts
What is the transfer of a patch of healthy skin taken from a donor site to cover a wound where new skin could not regenerate due to the stratum basal and its stem cells being destroyed called?
carotene
What is the yellow-orange pigment that gives egg yolks and carrots their color?
dermis
What is vascular dermis or epidermis?
stratum granulosum (nuclei and organelles begin to degenrate)
What layer in epidermis of skin has cells that are undergoing apoptosis due to the cell moving away from blood supply?
stratum lucidum
What layer is only found in thick skin? (fingertips, palms and soles)
stratum granulosum
What layer marks the transition between deeper, metabolically active strata and the dead cells of the more superficial strata?
stratum corneum
What layer of epidermis consists of 25-30 layers of flattened dead keratinocytes? (can be a few layers or up to 50)
stratum lucidum
What layer of epidermis is clear and has dead keratinocytes in thick skin?
subcutaneous layer
What layer serves as a storage depot for fat and contains large blood vessels that supply the skin?
when the sweat interacts with bacteria on the surface of the skin
What makes apocrine sweat have an odor?
inner medulla
What part of hair contains larger amounts of pigment granules in dark hair and lack of pigment granules in white hair?
papilla of the hair (from hair bulb)
What part of hair is a nipple shaped indentation that contains areolar connective tissue and many blood vessels that nourish the growing hair follicle?
cuticle of hair
What part of hair is most heavily keratinized and is arranges like shingles on the side of a house?
hair matrix
What part of hair is responsible for growth of existing hair and produces new hair its also the germinal layer of hair?
nail matrix
What part of the nail divides mitotically to produce new nail cells?
epidermis
What part of the skin is composed of keratanized stratified squamous epithelium?
migratory phase
What phase of deep wound healing does the clot become a scab and fibroblasts begin synthesizing scar tissue as well as blood vessels begin to regrow?
maturation phase
What phase of deep wound healing does the scab slough off and everyhing goes back to normal (fibers and fibroblasts)
proliferative phase
What phase of deep wound healing is characterized by extensive growth of epithelial cells beneath the scab, collagen fibers, and growth of more blood vessels?
hair
What protect foreign particles getting in your eyes, ears, and nose?
Nails
What protects the distal ends of digits and provides support and counterpressure to the palmar surface of finger? (touch perception and manipulation)
dermis (dermis has an extensive network of small blood vessels)
What serves as an important source of nutrition for the overlying epidermis?
hair follicle (external root sheath and internal root sheath)
What surrounds the root of the hair?
after birth-eccrine puberty-apocrine
What sweat gland starts to function soon after birth, and which one starts to function during puberty?
dermal papillae and epidermal ridges
What two parts of skin fit together to form an extremely strong junction between layers which strengthens the skin against shearing forces?
emotional sweating
What type of sweating occurs first on palms, soles, and axillae and then spreads to other areas?
when melanin-containing keratinocytes are shed from the stratum corneum
When is a tan lost?
third month of fetal development and are downward projections of the epidermis into the dermis between the dermal papillae and papillary region
Where and when are epidermal ridges found?
margins of lips, nail beds, glands penis, glans clitoris, labia minora, or eardrums
Where are eccrine glands not present?
dermis
Where do the fibers that anchor skin to the subcutaneous layer that also anchors it to underlying fascia extend from?
directly onto surface of the external auditory canal or into ducts of sebaceous glands
Where does the excretory ducts of ceruminous glands open up to?
subcutaneous layer
Where does the secreting portion of ceruminous sweat glands lie?
stratum spinosum
Where intraepidermal macrophages found?
deep to the shaft that penetrates into dermis and sometimes into subcutaneous layer
Where is the hair root?
lunula
White cresent-shaped are of the nail is called what?
because the ducts of sweat glands open on the tops of the epidermal ridges as sweat pores they leave a mark on a smooth object. (the sweat with the ridges)
Why are fingerprints formed?
progressive decline of melanin production
Why does hair become gray?
to shield the nuclear DNA from damage by UV light
Why does melanin granules cluster over nucleus on the side towrds the skin in keratinocytes? (epidermis)
its location
Why is skin so vulnerable to damage from trauma, sunlight, mibrobes, and pollutants in the environment?
because it doesn't shed and is stable
Why is tattoo ink deposited in the dermis?
large
a large or little amount of UV light causes skin cancer?
lipids and proteins
apocrine contains the same sweat components as eccrine glands but with
ducts and lumens
apocrine glands are also simple, coiled tubular but have larger what than eccrine glands
no
are apocrine sweat glands active during thermoregulatory sweating?
blood vessels, nerves, glands, and hair follicles are embedded in what layer of skin?
blood vessels, nerves, glands, and hair follicles are embedded in what layer of skin?
fibroblasts macrophages, and a few adipocytes
cells in the dermis include?
ability to return to original shape after stretching
collagen and elastic fibers in reticular region also provides the skin with elasticity which means what?
papillary region
collagen fibers of reticular region are more netlike and and have a more regular arrangement than those where?
bluish
cyanotic is when skin appears what color with blood not picking up adequate amount of oxygen to lungs?
binds cells of the stratum basale to each other and to the cells of the adjacent stratum spinosum
desomoseome in the stratum basale that are attached to keratin intemediate filaments in keratinocytes connect what?
kidneys
eccrine glands also eliminate waste, urea, uric acid and ammonia from body but what other part of body has plays more of a role in this?
epithelial tissue
epidermis (superficial layer of skin) is composed of what tissue?
vitamin D
exposing the skin to a small amount of UV light is actually necessary for the skin to begin the process of synthesis of what?
melanin in patches
freckles is the accumulation of what?
sensitivity, cooldness, warmth, pain, tickling and itching
free nerve endings in dermis initiate what sensations
structure specialization
free nerve endings in dermis lack what?
migratory phase
granulation tissue is tissue filling the wound in what phase?
protect the body
hair and nails have what function?
red blood cells
hemoglobin is an oxygen carrying pigment in what cells?
exposure and friction stimulates increased cell and keratin production (abnormal thickening)
how are callus formed ?
5 (stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and a thick stratum coneum)
how many layers are in thick skin?
4.5-5 kg
how much does skin weigh in adults (about 7% of body mass)
basement membrane
in epidermal injuries basal cells that surround injurty break contact with what
keratinocytes
in the epidermis long slender melanocytes projections extend between keratinocytes and tranfer melanin granules to what?
injury
keratin protects deeper layers from what?
apoptosis
keratinocytes in stratum granulosum undergo what? (hint: they're dying)
divide
keratinocytes in the stratum spinosum have the same organelles as cells of the straum basal and SOME retain the ability to what?
(decrease amount of water) and foreign materials
lamellar granules blocks what from entering the skin?
pressure
lamellated corpuscles are sensitive to what?
dried and treated dermis
leather is dried and treated what of other animals?
translucent
light skinned individuals have little melanin in epidermis so the epidermis is what?
True
lymphatic system can flush out tattoo particles making them fade . T or F
melanocytes
melanin granules protect keratinocytes, but what cell is susceptible to damage by UV light? (epidermis)
damage
melanin protects, which causes it to increase production in response to DNA what?
tactile discs
melanocytes and tactile epithelial cellls with associated what are scattered among the keratinocytes of the basal layer
True
melanocytes are also present in the mucous membrane T or F
melanin
melanocytes produces what? in epidermis
true
multiple layers of dead cells in stratum corneum protect deeper layer from injury and microbes T of F
radiation therapy, chemo, age, genetics, gender and severe emotional stress or illness
normal hair loss is 70-100 hairs per day and growth and replacement can be altered by what?
dermis
nutrients and oxygen diffuse to the avascular epidermis from what where ?
integumentary system
oil and sweat glands are part of what system
keratinocytes
once inside what cell does the melanin granules cluster to form a protective veil over the nucleus, on the side toward the skin surface? (epidermis)
elastic and collagen
papillary region contains what fibers
reticular region
regular arranged collagen fibers helps skin resist stretching where?
integumentary system
sensory information about the surrounding environment is provided by what?
cutaneous sensations
skin also stores blood and detects what?
true
skin is important to self-image and many people spend a great deal of time and money to restore it to a more youthful appearance. True of False
true
skin is the largest organ of the body in weight. T or F
stratas or layers of epidermis
stratum basale, stratum spinosum, stratum granulosum, and a thin stratum coneum are the four what?
areolar and adipose tissue
subcutaneous also called the hypodermis consists of what two tissues?
lamellated corpuscles (pacinian corpuscles)
subcutaneous layer and sometimes dermis contains nerve endings called what?
regulates body temperature
sweat glads have what function
exocytosis (merocrine secretion)
sweat glands (eccrine and apocrine) release their secretion through what manner?
touch sensations
tactile epithelial cells and associated tactile discs detect what?
dermis
tattooing is permanent coloration of skin with a needle into macrophages in what layer?
embryonic epidermis
the accessory structures of the skin- hair, skin, glands, and nails develop from what?
skin
the cutaneous membrane is also known as what?
dermal root sheath
the dense dermis surrounding the hair follicle is called what?
albinism
what is the inherited inability of an individual to produce melanin?
4 (stratum basale, stratum spinosum, stratum granulosum, and a thin stratum coneum)
thin skin is described as having how many layers?
pink to red (hemoglobin) depending on oxygen content
translucent epidermis in skin causes these individuals to have what skin color?
dermal papillae
what are small nipple shaped structures that projects into the undersurface of epidermis and increases surface area of papillary region ?
color of skin
what can provide clues for diagnosing skin conditions (sign of loss of oxygen or sign of buildup of a pigment)
capillary loops (blood vessels), corpuscles of touch nerve endings and free nerve endings
what do dermal papillae contain?
thick collagen fibers, elastic fibers fibroblasts and macrophages
what fibers and cells are in reticular region of dermis
shed and replaced by deeper cells
what happens to cells in the outer stratum of the epidermis?
dermis
what has the ability to stretch and recoil easily?
statum spinosum
what is (superficial) right on top of the stratum basale?
fibroblasts
what is a predominate cell of the dermis?
depilatory
what is a substance that removes hair
dandruff
what is an excessive amount of keratinized cells of scalp called
plasma membrane of adjacent cells
what is arranged in complex wavy folds that fit like a puzzle in stratum corneum?
Cells that move up from one epidermal layer to the next, accumulating more and more keratin
what is keratinization?
electrolysis
what is the electric current used to destroy hair matrix so hair cannot regrow?
what is the thin superficial region and thick deeper region of the dermis called?
what is the thin superficial region (1/5th) and thick deeper region of the dermis called?
stratum basale
what layer of epidermis cells receives more nutrients and oxygen, and cells are more active ?
arrector pili
what muscle extends from superficial dermis of the skin to the dermal root sheath around the side of the hair follicle?
blood vessels, nerves, hair follicles , sebaceous (oil) glands, and sudoriferous ( sweat glands)
what occupies spaces between fibers and cells in reticular region
dermis
what part of the skin is composed of dense irregular connective tissue? (with collagen and elastic fibers that resist pulling and stretching)
growth stage
what stage of hair growth does the matrix divide
apocrine
what sweat gland secretes sweat during sexual activity?
connective tissue
what tissue is the dermis composed of?
dermis
what's thicker epidermis or dermis?
When outer layer of epidermis are stripped out (burns and abrasions)
when does the rate of cell division in stratum basale increase ?
above surface of skin
where is the hair shaft?
fatty areas of the dermis and subcutaneous layer
where is vitamin A stored if a lot is taken in, which might cause light skin individuals to turn orange?
inflammation phase
which phase of deep wound healing involves blood clot and inflammation and phagocytotic white blood cells called neutrophils?
