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38 Cards in this Set
- Front
- Back
Fxns of Skin
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1. Physical Protection
Barrier from external agents Prevents dehydration 2. Immune protection 3. Thermoregulation(sweat glands) 4. Sensation(Pressure, heat, pain) 5. Secretion-sweat 6. Absoprtion-uv radiation for vitamin d |
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Layers
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1. Epidermis
-sufrace epithelial cell -keratin -other 2.Dermis -midde supporting -blood nerves ct 3. Subcutatenous -deepest, fat, glands, blood vessels |
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Epidermis contents
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1. Stratified, Squamous Epithelium
called kertinocyes |
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Layers of Kertainocytes
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Bottom-top
1. basal 2. spiny 3. granular 4. cornified |
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Basal Layer
made up of? Location? Mitosis? Shape/nucleus? fxn? |
1. Basal stem cells
2. ret of basement membrane ony layer which is attahced(hemidesomones) 3. Mitoticly active 4. Cuboidal, oval nucleus 5. Replenishes the skin layer |
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Basal Layer cells problems
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Mitotically active-->mutations
E.G. basal cell carcinoma |
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Spiny Layer
cell layer thickness? rich in ? mitotically? shape? |
1. thickest cell layer
2. Rich in cytokeratin(radiate to inerdigitate cell attachments) 3. Sometimes mitotically active 4. cobble-stone, polyhedral appearance; spiny |
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Spiny Layer Filaments? Granules?
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Abundant tonofilaments towards skin-->tonofibrils
Lamellar Grandules-->water proof |
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Granular Layer
thickness? special? release? contain? shape? |
1-3 layers
dying lipid lamellar granules-glue+water proof Kertohyaline granules(protein rich, blue) Flat |
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Cornified Layer
Layers? connections? keratin? fate? time to reach this layer? appearance? |
several layers of dead flat kertinoycytes-"ghosts" no nuclue/organelles, PM present
no desmosome cnxns tons of keratin ghost slough off via desqumation 2 weeks to reach this layer Pink |
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Cornified Layer in body
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-thin skin-->thin cornified layer, few layers of spiny cells
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Thick skin
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-in areas of more wear/tear- thicker layer of cornified
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Cells other than kertinocyes in the epidermis
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1. melanocytes
2. langerhans 3. merkel |
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Melanocytes
produce? located? derived? |
1. melanin- cells w/ melanin are kertainocytes not melanocytes
2. basal layer of epidermis-round cell no desmosomes 3.Neural Crest NO pigmented granules |
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Melanin fxn
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protect from UV
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Melanin Production
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Melansomes contain tyrosinase
Tyrsosine is converted to DOPA(tyrosinase)-->melanin Melanin-->absorbed by keratinocytes mostly in mitotically active cells basal and spiny(most uv suspect) and absorbs UVs |
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Melanin in Skin Color
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# melanocytes = in all races
1/10kertinocyes Skin color= number and size of melanosomes in keratinocytes(more = darker) |
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Langerhans
fxn? presence? from? |
immune response- eat antigen then present in surface to produce response
present in all layers orginate from bone marrow(blood-->skin) |
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Merkel Cells
special? where? originate? |
specialized touch receptors synapse with peripheral nerves
scatted in basal layer(can't tell from melanocytes, pail cyto, oval nuc) Neural crest cells, blood-->skin |
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Epidermis characterisitcs
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Rete Ridge-downward growth into dermis- more pronounced in areas of stress(fingers)
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Dermal Pegs
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areas where dermis pushes into epidermis, areas of stress as well
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Pathology: Psoriasis
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Increase basal cells
incomplete keratinziation of upper layer cells -->Shedding |
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Pathlogy: Malignant Tumors
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Carcinomas
basal squamous melanoma |
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Basal Carcinoma
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slow growing from chronic sun exposure
increase risk with dna repair deficits and immuno suppresion |
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Squamous Cell Carcinoma
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Exposure to UV light
increase risk with immuno-suppression and dna repair deficits |
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Melanomas
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common
invasive and metastatic Deadly sun expose heriditary |
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Dermis
where? contains? |
Middle supporting layer
blood, nerves, CT CT:extracellular fibers colagen+elastics Derived form mesoderm |
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Dermis Nerve Endings
location? Receptors? |
Meissner Corpuscles
dermal papillae(jxn with epidermis) Tips of finds, lips, eyelids mechanoreceptors |
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Pacinian Corpuscles
located? shape? fxn? |
dermis/subcut region
large onion detects pressure/vibration |
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Subcutaneous layer
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1. deepest
2. fat glands bigger blood vessels 3. lose connective tissue |
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Other structures of skin:
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Glands: Eccrine, apocrine, sebaceous
Hair Nails |
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Eccrine Sweat Glands
fxn? location? shape of secretry and duct cells |
regulate temp
deep in dermis Secretory: single layer cuboidal, narrow lumen, surround by myoepithelium(squeezer) Duct-2 layers of cuboidal epithelium |
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Eccrine Duct?
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Ducts goes through epidermis and keratin layer
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Pathology of eccrine sweat glands?
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Cystic Fibrosis
disorder of epithelial transport of CL by channel protein CFTR channel proteins are located in eccrine sweat ducts -->sweat released has high Cl/Na concentration |
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Sebaceous Glands
Secrete? Near? Located? Appearance? |
oily, waxy substance -->sebum(cholestrol, triglycerides, cellular debris)
holocrine-->gland dies and becomes secretion Hair follicle(released into hair shaft) Everywhere Round, plump, lipid filled fluffy cells |
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Apocrine Sweat Glands
Wher? fxn? what? location? |
arm put, groin, nipple, ear
unknoiwn downgrowth of epidermis deep in dermis or subcut. region duct leads to hair follicle |
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Appocrine
Production? Shape? |
viscous milky secertion when nervous
secretory:simple cuboidal w/ myoepithelium always near hair follicle shaft |
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Hair Follicle
derived? landmarks? |
Epiuthelium
hair bulb-dermis blood vessels and nerve endings germ cells fibrocollagne follicle sheath erector pili muscle-goose bumps sweaty glands nearby |