Integumentary System

Intro + Accessory Structures **DOES NOT** INCLUDE SKIN COLOR SECTION

Epidermis

Most superficial layer of skin; made of stratified squamous epithelium

Keratinocytes

The most abundant epidermal cells, they function mainly to produce keratin

Melanocytes

Spidery-looking black cells that produce the brown-to-black pigments called melanin

Dermis

Dense, irregular connective tissue layer of the skin deep to the epidermis

Keratin

Protein that is responsible for the strength and water resistance of the skin surface

Collagen

A protein that is a main constituent of connective tissue and give the dermis its flexible strength

Melanin

A natural pigment that protects the cells in the skin from the hazardous effects of UV radiation by absorbing sunlight

Hypodermis

Deep to the skin, this layer of adipose tissue provides insulation and padding

stratum corneum

the most superficial layer of the epidermis consisting of dead cells

stratum basale

deepest epidermal layer made of a single row of cells that undergo rapid cell division

stratum spinosum

a layer of the epidermis that provides strength and flexibility to the skin, appears spiky, and is located just above the stratum basale

stratum granulosum

"Grainy layer" of cells that are actively producing keratin

stratum lucidum

a layer of the epidermis that is translucent due to keratin-filled dead skin cells found only in the thick skin of the fingers, palms, and soles

vascular

describes the dermis which has blood vessels

avascular

describes the epidermis which lacks blood supply

superficial fascia

another name for hypodermis which means "above the flesh"

subcutaneous layer

another name for hypodermis which means "below the skin"

callus

area of thick hard skin

desmosomes

Anchoring junctions that prevent cells from being pulled apart

dendritic cells

cells in the skin that detect pathogens and alert the immune system

tactile cells

sensory touch receptors also known as Merkel cells

integumentary system

organ system consisting of the skin, hair, nails, and some glands

Vitamin D

the sunshine vitamin; requires UV light on skin to synthesize

cutaneous

pertaining to the skin

integument

Latin for "covering"

hair

outgrowth of the skin composed of compacted keratin strands

follicle

epidermal infoldings that each house a single hair

papilla

any small projection

matrix

actively dividing cells at the base of a hair or nail

arrector pili

tiny muscle fibers attached to the hair follicles that cause the hair to stand erect

sebum

oil

medulla

kiddle

cortex

outermost layer

hard keratin

protein that makes up hair and nails

lunule

an opaque white crescent at proximal end of nail

nail folds

skin folds that overlap the border of a nail

eponychium

cuticle

hyponychium

edge underneath the nail end; aka the quick

Koilonychia

"spoon nail" sign of iron deficiency

malnutrition

indicated by lines on the nails

sudoriferous glands

sweat glands

eccrine glands

glands that produce watery sweat; found over most of the body

apocrine glands

Sweat glands in the pubic and underarm areas that secrete thicker sweat, that produce odor when they come in contact with bacteria on the skin

ceruminous glands

modified sweat glands, located in external ear canal, secretes cerumen (earwax)

sebaceous glands

secrete sebum (oil) into the hair follicles