The Integumentary System

Front 1

Epidermis

Back 1

The stratified squamous epithelium consists of keratinocytes, melanocytes, Merkel cells, and Langerhans cells.

Front 2

Stratum basale

Back 2

The deepest epidermal layer, firmly attached to the basal lamina. This layer is composed of basal cells, or large stem cells.

Front 3

Stratum spinosum

Back 3

Each time a basal cell divides, it is pushed into the stratum spinosum, which is several cells thick.

Front 4

Stratum granulosum

Back 4

A water-resistant layer superficial to the stratum spinosum. Composed primarily of keratinocytes, this layer prevents diffusion of nutrients and waste of more superficial epidermal layers, causing cells to die.

Front 5

Stratum lucidum

Back 5

A glassy, "clear-layer," that cover the stratum granulosum in the thick skin of palms and soles.

Front 6

Stratum corneum

Back 6

The most superficial layer of thick and thin skin, composed of 15-30 layers of dead cells.

Front 7

Dermis

Back 7

Layer of skin that lies deep to the epidermis, composed of a superficial papillary layer, and a deeper reticular layer.

Front 8

Papillary layer

Back 8

Consists of loose connective tissue, containing the capillaries supplying the epidermis and axons of sensory neurons.

Front 9

Reticular layer

Back 9

Consits of dense irregular connective tissue, that surrounds blood vessels, hair follices, nerves, sweat glands, and sebaceous glands.

Front 10

Lines of cleavage

Back 10

The orientation of collagen and elastic fibers as stress is placed on the skin during normal movement.

Front 11

Cutaneous plexus

Back 11

Network of vasculature that supplies adipose tissue and tissues of the skin.

Front 12

Papillary plexus

Back 12

Network of vasculature, primarily capillaries, at the epidermal-demal boundary.

Front 13

Superficial fascia

Back 13

Or, subcutaneous layer, is important in stabilizing skin in relation to underlying tissues such as skeletal muscle or organs.

Front 14

Sebaceous glands

Back 14

Or, sweat glands, produce a waxy or oily secretion into hair follicles, called sebum, which coats the keratin of the hair.

Front 15

Sebaceous follicles

Back 15

Sebaceous glands which never produce hair. Presence of bacteria here produces inflammation, known as folliculitis, in which the gland becomes blocked causing a furuncle, or boil.

Front 16

Apocrine sweat glands

Back 16

Sweat glands that release axillary, areolar, and inguinal secretions. Typically viscous, cloudy, and odorous.

Front 17

Merocrine sweat glands

Back 17

Widespread sweat glands that produce "sweat," or sensible perspiration, that function for thermoregulation, excretion, and protection.

Front 18

Mammary glands

Back 18

Anatomically related to apocrine sweat glands, secretion is controlled by sexual and pituitary hormones.

Front 19

Cerumnious glands

Back 19

Modified sweat glands located in the external auditory canal. They produce cerumen, or "earwax", which coats and protects tiny hairs in the ear canal from particles and insects.

Front 20

Eponychium

Back 20

Or, cuticle, is a portion of the stratum corneum which extends over the exposed nail nearest the root.

Front 21

Hyponychium

Back 21

The free edge of the nail body which extends over a thickened stratum corneum.

Front 22

Psoriasis

Back 22

Stem cells in the stratum basale become unusually active causing hyperkeratosis in specific areas, creating small silvery scales that continuously flake off.

Front 23

Hyperkeratosis

Back 23

The increased production of keratin, often causing calluses or corns.

Front 24

Xerosis

Back 24

Plasmalemmae in the outer layers of the skin gradually deteriorate and the stratum corneum becomes more a collection of scales than a single sheet.

Front 25

Acne

Back 25

Sebaceous glands become blocked and secretions accumulate, causing inflammation and a fertile zone for bacteria.

Front 26

Seborrheic dermatitis

Back 26

Inflammation around abnormally active sebaceous glands. The scalp is most often involved, causing dandruff.

Front 27

Basal cell carcinoma

Back 27

Malignant cancer that originates in the stratum basale, two thirds of which are a result of chronic UV exposure. Metastasis almost never occurs.

Front 28

Squamous cell carcinoma

Back 28

Less common, but almost completely restricted to sun-exposed areas. Metastasis seldom occurs.

Front 29

Malignant melanoma

Back 29

An extremely dangerous condition in which cancerous melanocytes grow rapidly and metastisize throughout the lymphoid system.

Front 30

Capillary hemangioma

Back 30

Or birthmark, is caused by a tumor in the capillaries of the papillary layer of the dermis.

Front 31

Erythema

Back 31

Redness cause by dilation due to capillary dilation.

Front 32

Granulation tissue

Back 32

A combination of fibrin, fibroblasts, and capillaries that form during tissue repair.

Front 33

Keloid

Back 33

A thickened area of scar tissue formed by a shiny, smooth, epidermal surface.

Front 34

Papule

Back 34

A circumscribed, solid elevation in the skin.

Front 35

Scab

Back 35

A fibrin clot that forms at the surface of the skin.

Front 36

Vesicle

Back 36

Or pustule, is a small, circumscribed elevation of the skin containing fluid.