Color 16744448

What are the sensation by nerves for?-Temp, touch, pressure, and pain

What does the tissue excrete small amountsof?-Salt, organic wastes (urea), and immunityagainst bacteria

Synthesis of VitD-UV light helps produce vita (aids in Ca2+ & Phosphorus absorption)

Epidermis-Outer layer of stratified

Stratum Basale-Bottom layer of cells that divide

Keratinization-Older cells pushed up from stratum basal and harden as cells die and percentage of keratinncreases

Stratum Corneum-Top layer of dead keratinized cells

Melanin-Dark pigment that absorbs UV light.

Basement Membrane-connects epidermis and dermis

Dermis-Inner layer of loose connective tissue

Parts of a Dermis-Collagen, elastin fibers, blood vessels, smooth muscle, nerves

Dermal Papillae-Projections of dermis making an uneven edge between epi and dermis which form fingerprints

Macrophages-Wandering eater cells

Subcutaneous layer-Loose connective and adipose tissues binding skin (dermis) to underlying tissue

Calluses and Corns-increased mitosis where skin rubs; results in thickened areas

Pressure Ulcer or Bed sores-Blood flow to skin interrupted by pressure from maintaining one position too long. Cells die, tissues break down (necrosis).

Accessory Organs types-Nails, Hair Follicles, Sulorlferous, Nerves

Function of Nails-Protect ends of fingers and toes

Lunula-Half moon region of fasted cell division. New cells highly keratinized.

Hair Follicles-Tube like depression that holds hair.

Hair Root-Produce new cells by mitosis. Old cells pushed toward surface and die

Lots of Melanin-Dark Hair

Medium Melanin-Blonde Hair

No Melanin-White Hair

Mix of Melanin-Grey Hair

Trichosiderin in Melanin-Red Hair

Sudoriferous-Ecrine, Apocrine, Ceruminous, Mammary, Sebaceous glands

Ecrine Gland-water, salt, urea, andurin acid are used to cool the body

Apocrine Gland-Axillary regions, groin get active when upset or frightened or in pain

Ceruminous Gland-Modified to decorate ear wax

Mammary Gland-Produce milk postpartum

Sebaceous Gland-Produce Sebum (oil)

Meissner's Corpuscle-Touch receptors, superficial and closer to surface

Pacinian Corpuscle-Pressure receptors, deep and deeper in Dermis

Thermoreceptors-Free nerve endings for temp

Pain Receptors-Free nerve endings for pain

1st Step of Exercise-Muscles produce heat

2nd Step of Exercise-Blood carries heat away

3rd Step of Exercise-Blood reaches brain

4th Step of Exercise-Hypothalamus compares to set point

5th Step of Exercise-Message sent out to dilate dermal blood vessels

6th Step of Exercise-Heat escapes

1st Step of Cold Temp-Hypothalamus detects

2nd Step of Cold Temp-Dermal vasoconstriction

3rd Step of Cold Temp-Reduced heat loss

4th Step of Cold Temp-Skeletal muscles contract (shiver)

Inflammation-Swelling due to blood vessel dilation, fluids leave vessel carrying nutrients & oxygen

1st Degree Burn-Epidermal cells only. Redness & swelling. Heals in up to two weeks with no scarring.

2nd Degree Burn-Destroys some epidermis & some dermis. Blisters, colored from deep red to white. Heals by accessory organs epithelial mitosis

3rd Degree Burn-Destroys epidermis, dermis, and accessory organs. Skin dry & leathery, red to black to white. Heals from epithelial cells spreading in from the margins or transplant

Carcinmas-Basal cell carcinoma or squamous cell carcinoma. Most common type. Orginates in epithelial cells. Slow growing.

Melanomas-Malignant melanomas or melanocarcinomas. Uncommon./5% of skin cancers. Originates in melanocytes. Fast growing and spreads.

Characterstics of Melanomas-Asymmetry, border irregularity, color uneven, diameter, larger than a pencil eraser. Any mole that changes, itches, or bleeds.