Term
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Definition
1) Protection: Physical and chemical barrier to outside elements
2) Form: smooths out surface of layers deep to it
3) Maintain Hydration: Helps keep water in system
4) Temperature Regulation: heating/ cooling
5) Vitamin D Production
6) Detection of Stimuli
7) Blood Reservoir: Blood can be diverted away from skin to go to other organs
8) Excretion: removal of waste & water (sweat) |
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Term
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Definition
Epidermis: thin layer; most superficial; thick keratinized squamous epithelium; 4 cell types; 4-5 layers
Dermis: thick, 2nd(deep)layer; Strong connective tissue; bound together with fibers; matrix synthesized by fibroblasts |
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Term
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Definition
1)Keratinocytes: most numerous; backbone; deep layer is mitotic
2)Melanocyte: Basal layer of epidermis; makes melanin- once synthesized, melanin sent from melanocyte to kerotinoctyes (protects kerotinocytes from UV rays)
3)Langerhan's Cells: dendridic cell; manufactured in bone marrow
4)Merkel Cells: sensory receptor cells; associated with nerve ends |
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Term
| Layers of Epidermis (deepest to superficial) |
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Definition
1)Statum Basale (germinativum): bottom/deepest/youngest layer; single cell; mitotic
2)Statum Spinosum: spiny projections because cells retract
3)Statum Granulosum: flattened with modified keratin which forms granules which contain waterproofing glycolipid (keeps water from penetrating into body); last cells to be nourished by blood by diffusion; last layer of living cell
4)Statum Lucidum: only present in thick skin (palms/soles of feet)
5)Statum Corneum: thickened plasma membranes; protects deeper cells; cornified; desquamation(part that flakes off); 20-30 cell layers thick |
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Term
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Definition
1)Papillary layer: thin, superficial layer of connective tissue; many blood vessels, projections and
indentations, and dermal ridges
2)Reticular layer: deeper and much thicker; bundles of collagen fibers; dense irregular connective tissue; collagen gives strength and binds water; elastin gives recoil properties; striae=collagen tearing |
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Term
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Definition
1) Melanin: protein responsible for yellow, red, tan, and black; made in melanocytes; accounts for racial differences; Freckles/moles-concentration of melanin
2) Carotene: yellowish; from eating yellow vegetables/egg yolks
3) Hemoglobin: blood/redness; give you healthy look |
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Term
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Definition
Appendage of the skin; layers of dead keratinocytes
-primarily hard keratin
-shaft projects from skin
-Root imbedded in skin; not visible
-color determined by melanoctyes at base of follicle;
-Hair follicle extends deep to dermis and hypodermis |
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Term
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Definition
Appendages of the skin; modification of existing epidermis
-Hard keratin:(like statum corneum);for protection and grip on dorsal side
-Nail matrix(like statum germinativum of epidermis); where keratinocytes reside to generate the nail |
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Term
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Definition
Appendages of the skin
- Sweat: function is temp regulation;
- Sebacious:(oil glands); outgrowths of hair follicles; secrete sebum (oily lipid); Hormonal stimulation at puberty (clogged duct causes infection/acne)
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Term
| Hair Shaft (shape and layers) |
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Definition
-Shaft Shape equals the shape of hair; flat=curly, oval=wavy, Round=straight
Layers:
1)Medulla: innermost, bulky layer of flattened cells, softer keratin
2)Cortex: middle layer
3)Cuticle: outermost; single layer of keratinoocytes (arranged like shingles); maintains integrity of hair shaft and keeps shafts separate |
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Term
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Definition
| 1)Hair Bulb: contains statum germinativum (mitotic kerotinocytes); push up and outward to form hair layers 2)Root Hair Plexus: nerve/sensation 3)Papillae: blood supply to statum germinativum; melanocytes sit on top 4)Arrector Pili Muscle: attached to hair shaft; contracts when scared/cold; causes dimpling of overlying skin |
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Term
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Definition
1) Eccrine (merocrine): coiled, tubular gland open on much of body but concentrated on skin of palms, forehead, and soles of feet; ultrafilate of blood controlled by C.N.S
2) Apocrine: also merocrine but located in axillary regions; larger than eccrine; ducts empty into hair follicles (deeper in dermis/hypodermis); sweat, fat and protein but odorless (bacteria causes odor); begins functioning at puberty (not involved in temp regulation- just scared or exercising?
3) Ceruminous: wax producing gland in external ear canal; protects/keeps ear clean
4) Mammary: secretes milk |
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