Epidermis, Dermis, Hypodermis

Epidermis

-outermost
-stratified squamous epithelium
-innermost layer constantly goes through mitosis
-No blood vessels
-uses diffusion for O2 and nutrients
-keratin: toughens and waterproofs
-Melanin: produced by melanocytes for skin color

Stratum Basale

burned
-stem cells that divide to create keratinocytes
-tightly bound to the dermal layer
-contains stem cells, melanocytes, and merkel cells

Stratum spinosum

sun
-Prickly Layer: desmosomes between cells bond them together
-cells producing keratin
-Contains Langerhans cells which act as microphages (immunity)

Stratum Granulosum

get
-Granules form in cells as keratin builds up
-produce glycolipid to waterproof the skin
-the cell begins to die as keratin builds up

Stratum Lucidum

lets
-smooth translucent layer
-only in thick layers
-cells are dead

stratum corneum

come
-uppermost layer of skin
-cells are flat and dead
-15-30 layers thick

Dermis

-Deeper and thicker
-mainly of connective tissue
-contains collagen and elastic fibers
-has many blood vessels
-contains a network of nerves, hair follicles, and glands

Subcutaneous

-layer of connective tissue and fat under the skin
-insulates the body
-stores fat
-cushions and protects underlying tissues
-attaches to muscle