1.12 Skin Flashcards
4 layers of epidermis
- stratum corneum
- stratum granulosum
- stratum spinulosum
- stratum basale
Which is the outermost layer of the skin?
stratum corneum
Which is the innermost layer?
stratum basale
function of the stratum corneum
- provides protection from infection
- waterproofing
- dry
function of stratum granulosum
water retention
function of stratum spinulosum
holds the two outer layers to the stratum basale
function of stratum basale
- regeneration of skin
- nutrient transfer
How is the stratum basale able to make new cells?
- because it’s in contact with the vascular dermis
- nutrient transfer occurs via osmosis
3 layers of skin
- epidermis
- dermis
- subcutaneous
keratinized
- dead, can’t absorb anything
- can be COATED
mucous membranes and keratinization
not keratinized, can absorb substances
How do the shapes of epidermal cells change from layer to layer?
go from columnar to flat from stratum basale to stratum corneum
shape of the interface between the dermis and epidermis
valleys and peaks
Why are there valleys and peaks in the interface between the dermis and epidermis?
- increases surface area
- greater strength against friction and shear forces
Why is greater surface area beneficial in the interface?
more opportunities for osmosis
What would happen if there weren’t valleys and peaks in the interface between the dermis and epidermis with respect to shear and friction?
- blister formation
- skin sliding
What happens to the interface between dermis/epidermis as you age?
- flattens out
- much easier to tear
How many layers in the dermis?
2
What are the 2 layers of the dermis?
- papillary
- reticular
function of the papillary layer of the dermis
nourishes the epidermis
function of the reticular layer of the dermis
binds everything above to the layer below
What do the layers of the dermis contain for strength and elasticity?
- collagen
- elastin
thickness of the dermis compared to epidermis
dermis is 20-30x thicker
examples of epidermal appendages
- hair follicles
- sebaceous glands
- sweat glands