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112 Cards in this Set
- Front
- Back
2 layers of the skin |
epidermis and dermis |
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Below the dermis is the _________, not technically a layer of the skin. |
hypodermis |
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Thicker skin has _______ glands, but no ______ or sebaceous glands. |
sweat, hair, sebaceous |
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Why do areas such as the palms of the hands, soles of feet, fingers, and toes, have thicker skin? |
Thicker skin covering these areas helps with friction and heat protection. |
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The skin is durable (able to withstand wear, pressure, or damage) due to a tough protein called __________ . |
keratin |
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Keratin is produced by cells called _____________. |
keratinocytes |
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Superficial layer of the skin? |
epidermis |
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The epidermis is made up of ... |
keratinized stratified squamous epithelium |
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What makes the epidermis tough and waterproof? |
keratin |
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Skin cells are linked by... |
desmosomes |
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The epidermis is avascular (has no blood vessels). Therefore, it receives nutrients from the dermis by... |
diffusion |
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The sparse (thinly dispersed or scattered) nerve endings in the epidermis detect... |
mild pain and light touch |
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The melanocytes are located in the _________ region of the epidermis. |
deepest |
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Melanocytes synthesize pigment called __________. |
melanin |
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What is the function of melanin? |
gives skin its color based on how much is present in the epidermis, also based on DNA |
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few within the epidermis; detect touch |
tactile/merkel cells |
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immune cells; prepared in case microbes, toxins, pathogens penetrate the skin, then alert the immune system to respond |
dendritic/langerhans cells |
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undifferentiated cells in the deepest region of the epidermis; give rise to keratinocytes |
stem cells |
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make up most epidermal cells; make keratin |
keratinocytes |
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As keratinocytes are produced from stem cells, they are pushed (upwards/downwards) and push on older cells ahead of them. |
upwards |
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Keratinocytes die as they move closer to the surface of the skin. Why? |
Because they are far away from the blood vessels of the dermis. Therefore, they are too far away to receive nutrients. |
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Dead keratinocytes flake off in tiny specks called ________, or larger clumps called ___________ if stuck together in sebum (oil). |
dander, dandruff |
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________ is deep to the epidermis, rich in collagen. |
Dermis |
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Boundary between the epidermis and dermis is wavy. Why? |
It really holds/interlocks the layers together. |
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The upward projections into epidermis is called______. |
dermal papillae |
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The downward grooves are called__________. |
epidermal ridges |
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Superficial layer of the dermis |
papillary layer |
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Deep layer of the dermis |
reticular layer |
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Areolar tissue in this layer of the epidermis allows immune cells to move through; has rich supply of blood vessels |
papillary layer |
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Thicker than papillary layer; mainly composed of collagen |
reticular layer |
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When the collagen in reticular layer is stretched extensively and torn, it leaves permanent stretching called ________. |
striae |
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What exactly do we know striae as? |
stretch marks |
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________ is deep to the dermis, also called _________________ tissue. |
Hypodermis, subcutaneous |
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The hypodermis contains much ___________ and ____________ tissue. |
adipose, areolar |
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Why is the hypodermis ideal for drug injections? |
Because it is highly vascularized |
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hypodermic that is primarily composed of adipose tissue, not uniformly distributed |
subcutaneous fat |
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The subcutaneous fat is thicker in _______ than in __________. |
females, males |
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Locations of the subcutaneous fat in males |
abdomen |
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Locations of the subcutaneous fat in females |
hips, thighs, breasts |
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___________ people have more subcutaneous fat than ____________ people. |
Younger, older |
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What determines the skin color? |
melanin |
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brownish black color |
eumelanin |
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reddish yellow color |
pheomelanin |
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Everyone has the same number of melanocytes, but differences exist in... |
the amount of melanin being produced |
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Freckles and moles are local accumulations or clusters of... |
melanin |
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yellow-orange pigment obtained through the diet |
carotene |
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red pigment in blood, gives red-pink hue to skin, especially where skin is thinner like the lips |
hemoglobin |
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blueness of the skin due to lack of oxygen, usually occurs in areas such as fingers, toes, and lips |
cyanosis |
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redness of the skin due to blood coming into the surface of the skin, usually occurs when exercising and nervous |
erythema |
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paleness due to reduced blood flow to the skin, occurs when you're shocked or sick |
pallor |
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genetic lack of melanin due to nonfunctional tyrosinase enzyme |
albinism |
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___________________ enzyme is needed to form melanin from tyrosine. |
Tyrosinase |
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Yellowing of the skin due to elevated bilirubin; usually occurs due to liver damage, in first-born babies |
jaundice |
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Bilirubin is the result of... |
hemoglobin breakdown, usually removed by liver |
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bruise due to dotted blood pooling |
hematoma |
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What is hair composed of? |
hard keratin |
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Each individual hair is called a _______ and grows in a tube called a ___________. |
pilus (plural:pili), hair follicle |
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fine unpigmented hair of a fetus during the last three months of gestation (pregnancy) |
lanugo |
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fine, pale hair present on head of newborn, hair of children, face, stomach |
vellus hair |
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longer, coarser, more pigmented hair, locations include scalp, eyebrows, eyelashes, axillary (armpit) hair, pubic hair, male facial hair, some hair on trunks and limbs |
terminal hair |
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Each hair can be divided into ____ distinct zones. |
3 |
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What are the 3 zones of the hair? |
bulb, root, shaft |
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origin of hair in dermis or hypodermis, only living region of the hair |
bulb |
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within follicle, above bulb but not above surface of the skin |
root |
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portion of the hair that extends above the surface of the skin |
shaft |
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bulb receives nutrients from a bud of vascular connective tissue called... |
dermal papilla |
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Above dermal papilla is the ___________ |
hair matrix |
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What is the function of the hair matrix? |
It is the growth center of the hair, cells are mitotically active (cell division) |
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In cross-section, hair has ____ distinct layers. |
3 |
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innermost layer, contains cells and air |
medulla |
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middle layer, several layers of elongated keratinized cells, contains eumelanin and pheomelanin |
cortex |
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outermost layer, multiple layers of thin, scaly cells that overlap, interlocking with cells in the follicle |
cuticle |
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Hairs have ___________________ which allow the skin to stand upright in response to fear or cold temperatures. |
piloerector muscles |
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What detects when the hairs move. |
receptors |
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Hair-textures are based on... |
differences in cross-sectional shape |
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Hair alternates between the stages of hair growth, degeneration, and resting called... |
hair cycle |
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Hairs spend 90% of their time in anagen. What happens in anagen? |
Anagen is the growth phase. Stem cells multiply, forming root sheath, sheath cells become hair cells and make keratin. |
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mitosis stops, sheath cells die, base of hair keratinizes. |
catagen |
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Hair in the catagen is phase is now called____________ and loses anchorage. |
club hair |
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resting period until anagen beings again |
telogen |
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What are the time periods of the following: anagen, catagen, and telogen? |
Anagen: 6-8 years Catagen: 2-3 weeks Telogen: 1-3 months |
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thinning of the hair, resulting in baldness |
alopecia |
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What happens in alopecia? |
Hair is shed before it can emerged from the hair shaft. Follicles begin to form vellum hair instead of terminal hair. |
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Alopecia may worsen due to... |
immune system, stress, lack of nutrients |
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Hair things in certain regions of the scalp faster than other. |
pattern baldness |
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Genetic cause, only dominant in males, expressed in presence of high testosterone, cause replacement of terminal hair with vellum hair; recessive in women |
pattern baldness |
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excessive or undesirable hairiness in unhairy regions such as chin and upper lips; common in women with hypersecretion of testosterone |
hirsutism |
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What are nails composed of? |
thick keratin in parallel |
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Hard portion of the nail is called the... |
nail plate |
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The nail plate consists of... |
free edge, nail body, nail root |
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overhangs finger/toe, appears white |
free edge |
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attached portion, appears pink due to underlying blood vessels |
nail body |
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extends proximally into finger/toe |
nail root |
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Nail root is covered by... |
nail fold |
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underneath the nail plate is the___________ which is the location of mitosis |
nail bed |
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nail bed is thick, obscuring blood vessels... |
white lunule |
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also called sweat glands |
sudoriferous glands |
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What are two types of sudoriferous glands? |
apocrine and eccrine/merocrine |
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located in groin, anal region, underarms, areola, beard area in males |
apocrine |
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lead into hair follicles, produce secretion by exocytosis, ACTIVATED AT PUBERTY |
apocrine |
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located all over the body, especially on palms of hands, soles of feel, forehead |
eccrine/merocrine |
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What is the function of merocrine glands? |
to cool the body, eliminate some wastes |
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produce oily secretion called sebum |
sebaceous glands |
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produce secretion of sebum and dead epithelial cells, called cerumen, or earwax |
ceruminous glands |
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located in external ear canal; makes it waterproof and sticky |
ceruminous glands |
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produce breastmilk in response to hormones towards the end of pregnancy |
mammary glands |
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channel breastmilk through a duct to the nipple |
mammary glands |
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damage to cells in response to UV radiation and DNA damage |
skin cancer |
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epidermal cells, most common type, least deadly, seldom metastasizes (spread to another location) |
basal cell carcinoma |
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keratinocytes, easy to treat but can metastasize |
squamous cell carcinoma |
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melanocytes, aggressive and commonly drug-resistant, quickly metastasizes |
melanoma |
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ABCDE Method |
A-Asymmetry B-Border-distinct border of the spot C-Color-uniform color D-Diameter-smaller than head of eraser E-Elevation and Evolution |