Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Epidermis
chapter 6- integumentary system
| Term | Definition |
|---|---|
| Epidermis | - outerlayer - stratified squamous epitheliums -cornified or keratizinized to prevent water loss -avascular |
| Functions of Epidermis | - protect against water loss, harmful chemicals, mechanical injury, and pathogens |
| keratinization | - process of hardening, dehydration, and keratin accumulation - occurs in epidermal cells as they migrate outward |
| Keratin | - though, fibrous, waterproof, protein made and stored in cells - made of keratinocytes - form outermost layer, stratum corneum |
| stratum corneum | - location: superio (outermost) layer - characteristics: many layers of keratinized, dead epithelial cell that are flattened and non nucleated |
| Stratum lucidum (only present in thick skin) | - location: between stratum corneum and stratum granulosum on soles and palms - characteristics: cells appear clear; nuclei organelles, and and cell membranes are no longer visible |
| Stratum granulosum | - location: beneath the stratum corneum - characteristics: three to five layers of flattened granular cells that contain shrunken fibers of keratin and shriveled nuclei |
| Stratum spinosum | - location: beneath the stratum granulosum - characteristics: many layers of cells with centrally located, large oval nuclei and developing fibers of keratin; cells becoming flattened |
| Stratum basale | - location: deepest layer - characteristics: a single row of cuboidal or columnar cells that divide and grow; this layer also includes melanocytes |
| dedritic cells | - found in stratum basale -phagocytes; protect skin and underlying tissues from infection |
| tactile cells | - found in stratum basale -act as sensory receptors for light tough |
| melanocytes | - found in stratum basale -produce the pigment melanin - absorbs UV light from sunlight and provides skin color |
| melanin | - distributed to keratinocytes, to protect from UV radiation - Dan damage, fibroblast damage, skin cancer |
| eumelanin | brownish-black pigment |
| pheomelanin | reddish-yellow pigment |
| Skin Color- hereditary factors | - all people have the same amount of melanocytes, the amount of melanin produced is genetic - varying distribution and size of ,melanin granules - albinos inherit mutation in melanin genes; lack melanin |
| skin color- environmental factors | - sunlight - UV light from sun lamps - X-rays |
| skin color- physiological factors | - Oxygenation in blood or dermal vessels - vasodilation' vasoconstriction of formal blood vessels - accumulation of carotene pigment from diet |
| Basal cell carcinoma | - most common skin cancer, nonlethal |
| Squamous cell carcinoma | - rarely deadly cancer |
| Melanoma | - arise from melanocytes - least common (4% of skin cancer) - cause 80% of skin cancer death |
Created by:
quinnbrown
Popular Science sets