Insulates, cushions the underlying body tissue, protects the entire body from mechanical damage, chemical damage, thermal damage, bacterial damage
Cornfield layer
Hardened uppermost layer; prevents water loss
Capillary network
Regulating heat loss from the body surface
Dermis
Underlying connective tissue
Avascular epidermis
Keratinized stratified squamous epithelium
Keratinocytes
Most abundant epidermal cells;produce keratin fibrils; connected to each other by desmosomes
Keratin
Fibrous protein that gives the epidermis durability and protective capabilities
Melanocytes
Spidery black cells that produce melanin
Melanin
Nuclei of the cells in the deeper epidermal layers; shielding their genetic material from damaging effects of ultraviolet radiation
Epidermal dendritic cells
Langerhans cells; immunity
Tactile (merkel) cells
Conjunction with sensory nerve endings; sensitive touch receptors
Stratum Basale
Constantly undergoing mitotic cell division> stratum germinativum; 10% to 25% are melanocytes; receive adequate nourishment via diffusion of nutrients from the dermis
Stratum spinosum
thick weblike bundles of intermediate filaments made of a pre-keratin protein; receive adequate nourishment via diffusion of nutrients from the dermis
Stratum granulosum
abundant granules contained by cells 2 types; lamellated> waterproofing glycolipid secreted into extracellular space, Keratohyaline> forms the keratin fibrils
Stratum lucidum
translucent bond of flattened dead keratinocytes
stratum corneum
20 to 30 layers; cells are dead and flattened scalelike remnants are fully keratinized
papillary layer
composed of areolar connective tissue; uneven; superior surface> dermal papillae- attach it to epidermis above; allows heat to radiate to the skin surface, pain, touch receptors