✅
skin-
epidermis- ✅ the outer layer of the skin covering the exterior body surface
of vertebrates
dermis- ✅ the deep vascular inner layer of the skin
hypodermis-✅ layer of cells that secretes the chitinous cuticle
integument-✅ meaning covering
skin, hair, nails, glands-✅ components of the integumentary system
functions of integumentary system-✅ protection, sensation, temp
regulation, excretion, vitamin D protection
epidermis of the finger-✅
✅
dermis of the finger-
epipdermis- ✅1st major skin region (outside) Composed of stratified
squamous epithelium
keratinization-✅ process in which new cells (with keratin) push old cells to
surface
40-56 days for new cells to reach surface
strata of the epidermis-✅ (from most superficial to deep) stratum corneum
stratum lucidum stratum granulosum stratum spinosum stratum basale
stratum corneum- ✅ outermost layer of epidermis
20-30 layers of dead squamous cells filled with keratin
, accounts for 75% of epidermal thickness
Provides protection to deeper tissues from mechanical injury, inward or
outward diffusion of water & other molecules and invasion of
microorganisms
dandrufff-✅ excessive sloughing of s. corneum
✅ forms when stratum corneum has frequent friction
callus-
corn-✅ thickened s. corneum over bony bony prominences
stratum lucidum-✅ translucent and allowing light to pass through it easily
Absent in thin skin
stratum granulosum- ✅contains flattened cells pushed up from the deeper
strata
cells form protein granules
when cells leave this stratum, cells have died
stratum spinosum- ✅ multilayer of distorted (spined) cells
cells look spiny
stratum basale- ✅ deepest stratum of the epidermis
single sheet of columnar cells that continue to divide
firmly attached to dermis
Stratum Germinativum- ✅ S. spinosum + S. basale
epidermis- ✅
dermis- ✅
dermal papillae- ✅
duct of merocrine sweat gland- ✅