Functions and Layers of the Skin

Stratum spinosum

Irregularly shaped cells, several layers thick.

Melanocytes

Cells producing melanin for UV protection.

Basal cell carcinoma

Cancer from uncontrolled stratum basale cell division.

Squamous cell carcinoma

Cancer from uncontrolled stratum spinosum cell division.

Dermis

Layer of dense irregular connective tissue beneath epidermis.

Dermal papillae

Wavy layer creating fingerprints and increasing friction.

Papillary layer

Upper layer of dermis made of loose connective tissue.

Reticular layer

Lower dermis layer with collagen fiber bundles.

Functions of the skin

Protection, sensation, temperature regulation, excretion, vitamin D production.

Stratum corneum

Top layer of dead, keratinized cells, 20-30 thick.

Stratum lucidum

Thin, translucent layer in thick skin areas.

Stratum granulosum

Layer where cells flatten and accumulate keratin.

Stratum basale

Base layer where cells constantly divide.

Melanin

Pigment that protects against UV radiation.

Skin cancer

Uncontrolled cell division due to DNA mutation.

Melanoma

Cancer from uncontrolled melanocyte division.

Lines of cleavage

Collagen fiber arrangement important for surgical cuts.

Decubitus ulcers

Bedsores from restricted blood supply to skin.

Hypodermis

Subcutaneous layer connecting skin to underlying tissues.

Insulation

Function of hypodermis to retain body heat.

Nutrient storage

Hypodermis stores energy in fatty tissues.

Temperature regulation

Sweat and blood flow manage body heat.