Integumentary System 01

Carotene

yellow-orange pigment

Stratum corneum

the most superficial layer of the epidermis consisting of dead cells

Melanin

a dark brown to black pigment occurring in the hair, skin, and iris of the eye

Eumelanin

Produces brown to black pigments

Pheomelanin

Produces yellow to red pigments

stratum basale

deepest layer of the epidermis, made of epidermal stem cells

stratum granulosum

3rd layer of the epidermis, granular layer

stratum spinosum

The spiny layer just below the stratum granulosum

Melanoncytes

melanin producing cells in the epidermis

Dermis

Inner layer of skin

Epidermis

outermost, top layer of skin

Keratinocyte

epidermal cell that produces keratin

Langerhans (dendritic) cells

Immune cells (phagocytic) that respond against microbes and cancers; in stratum spinosum layer

Fibroblasts

In connective tissue, cells that secrete the proteins of the fibers.

Arrector pili

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

Cyanosis

bluish discoloration of the skin

Dermal Circulation and Skin Color

Increased circulation causes the skin to have a red/pink tint.

Decreased circulation causes the skin to appear very pale.

Cholecalciferol (Vitamin D3)

The form of vitamin D found in animal foods, supplements, and formed in the skin. This is the form absorbed from the skin into the blood

Calcitriol

A hormone produced from vitamin D

Epidermal growth factor

Abbreviated EGF; stimulates cells to reproduce and heal.

Papillary layer

Outermost layer of the dermis, directly underneath the epidermis

dermal papillae

Found in the upper layers of the dermis, they create your fingerprint pattern

Reticular layer

Deeper layer of the dermis that supplies the skin with oxygen and nutrients

Collagen fibers

provides flexibility and strength

Elastic fibers

Flexible and "stretchy" fibers that add elasticity to tissue

Dermatitis

inflammation of the skin's dermis

Skin turgor

properties of flexibility and resilience, dehydrated skin has reduced skin turgor

Cleavage lines

Collagen and elastic fibers in the dermis

Arranged in parallel bundles

Resist force in a specific directions

Dermal innervation

-extensive network of nerves in dermis

-monitors sensory receptors

-controls blood flow

-controls glandular secretion

Merkel (tactile) cells

Responsible for sensory actions in skin

Functions of integument

Protection of underlying tissues and organs

Excretion of salts, water, and organic wastes

Maintenance of normal body temperature

Production of melanin & keratin

Synthesis of vitamin D3

Storage of lipids

Detection of touch, pressure, pain, etc.

Coordination of the immune response

Accessory structures

hair, nails, glands

Stratum lucidum

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

Thick skin

Covers the palms of the hands and soles of the feet

Thin skin

Covers most of the body

Has four layers of keratinocytes

Basement membrane

Cells at the base of an epithelial layer are attached to this.

Keratinization

The process by which cells form fibrils of keratin and harden

Hypodermis

loose connective tissue layer of skin below the dermis