Integumentary system

apocrine Sweat gland-organ made of specialized cells that produces and secretes sweat; its duct opens into a hair follicle

Arretor pilli-bundle of smooth muscle associated with each hair follicle; its contraction pulls the hair follicle upright

Dendritic Cells-immune system cell that resides in the epidermis; functions to ingest foreign

dermal papillar

dermal papillar-substances and activate the immune system peg-like projections of dermis that indent the overlying epidermis

dermis

deep layer of the skin

eccrine sweat glands

organ made of specialized cells that produces and secretes sweat; its duct opens onto the surface of the skin

epidermis

superficial layer of the skin

eponychium

the proximal nail fold that projects onto the nail body; also called the cuticle

Free edge (of nail)

distal part of the nail that protrudes beyond the nail plate or body

hair

flexible strands consisting largely of dead, keratinized cells that protrude from the skin; also called a pili

hair bulb

expanded deep end of the hair follicle

hair follicle

sheath of epidermis that surrounds the hair root

hair matrix

dividing cells that create the hair; lie adjacent to the hair papilla

hair papilla

a dermal papilla that protrudes into the hair bulb; contains a knot of capillaries that feeds the hair matrix

hyponychium

thickened region beneath the free edge of the nail that secures the free edge of the nail plate at the tip of the finger or toe

Keratincytes

epidermal cell that produces keratin (a fibrous protective protein)

Lunule

the region of the nail plate or body that lies over the thick nail matrix and appears as a white crescent

melanocyte

epidermal cell that synthesizes melanin (a pigment that protects against ultraviolet [UV] radiation

nail

clear protective covering on the dorsal surface of the distal part of a finger or toe

nail bed

epidermis upon which the nail lies

hail folds

skin folds that overlap the proximal and lateral borders of the nail

nail matrix

thickened proximal portion of the nail bed responsible for nail growth

hail plate or body

visible attached portion of a nail

Papillary layer

thin, superficial layer of the dermis

Pore

the opening of a sweat gland duct onto the skin's surface

Reticular layer

thick, deep layer of the dermis

Root (of hair)

part of the hair embedded in the skin

Root (of nail)

proximal portion of the nail embedded in the skin

sebaceous gland

glands that secrete oil or sebum

Shaft of hair

visible part of the hair that projects above the skin's surface

epidermis

thin layer of tissue covering the body's surface

Subcutaneous tissue

layer of tissue that lies deep to the skin, anchoring it to the underlying structures

Tactile cell

an epithelial cell present in the epidermal-dermal junction that is closely associated with a sensory nerve ending; functions as a sensory receptor for touch