Layers of the Skin

epidermis

the superficial, thinner layer of skin, composed of keratinized stratified squamous epithelium

dermis

a layer of dense irregular connective tissue lying deep to the epidermis

subcutaneous layer

a continuous sheet of areolar connective tissue and adipose tissue between the dermis of the skin and the deep fascia of the muscles

stratum basale

the deepest layer of the epidermis consisting of stem cells capable of undergoing cell division to form new cells

stratum spinosum

a layer of the epidermis that provides strength and flexibility to the skin

stratum granulosum

a layer of the epidermis that marks the transition between the deeper, metabolically active strata and the dead cells of the more superficial strata

stratum lucidum

a layer of the epidermis found only in the thick skin of the fingers, palms, and soles

stratum corneum

the most superficial layer of the epidermis consisting of dead cells

dermal papillae

a fingerlike projection of the dermis that may contain blood capillaries or Meissner corpuscles (of touch)

hair follicle

a structure composed of epithelium that surrounds the root of a hair

shaft

the superficial portion of the hair

root

the portion of a hair that penetrates into the dermis and sometimes the subcutaneous layer

sebaceous gland

an exocrine gland in the dermis associated with a hair follicle that secretes oil

arrector pili

a smooth muscle attached to hair follicles that causes "goose bumps" to appear on the skin when contracted

pacinian corpuscle

a type of nerve ending located in the subcutaneous layer that is sensitive to pressure; also described as "lamellated"

free nerve ending

dendrites that lack any obvious structural specialization; used to generate sensations of warmth, coolness, pain, tickle, and itch

Meissner corpuscle

a tactile nerve ending receptor in the dermal papillae that is sensitive to touch