the outermost layer; contains keratin; non-vascular layer
Keratin
protein that is tough, waterproof; fill skin cells
Layers of the Epidermis
stratum germinativum, stratum corneum
Stratum Germinativum
layer of the epidermis that is the only one capable of producing new cells
Stratum Corneum
outer epidermis that flakes off as the skin renews itself
Melanin
pigment that gives skin its color; dark-skinned people will have more pigment; cells that are active and produce more melanin (freckles- irregular patches of melanin
Dermis
AKA corium; true skin; innermost layer; has blood vessels, nerves, and glands
Layer of the Dermis
subcutaneous layer
Subcutaneous Layer
has a generous supply of adipose tissue
Skin
classified as an organ; enveloping membrane; AKA integumentary system; does not breathe; heat is lost from the skin by evaporation
Skin Contains Kinds of Tissue
nerve, connective, epithelial
Skin Properties
pH slightly acidic, prevents growth of pathogens; contains compound converted to VitD (sunshine) when exposed-uv rays of the sun (ca assists absorption of Vit D); people who sunbathe more prone to wrinkles, skin cancers, dry skin & sunburn
Sweat Glands
regulate heat, odor, & sweat; called suderiferous glands; main function-regulate body temp.; when functioning, we perspire from pores; ceruminous
Pores
openings of the sweat glands
Ceruminous Gland
modified sweat gland; produce cerumen (ear wax) that protects the ear drum
Sebaceous Glands
sac-like structure that secretes sebum; secrete substances into a hair follicle; main function is to lubricate skin
Sebum
very oily substance
Hair
covers most of the body (not palms of hands or soles of feet); consists of dead cells and keratin; will grow as long as the follicle is not destroyed
Nails
originate in the outer layer of the epidermis; affected by general health; grow from the proximal end called the root
