Integumentary System

Nails

________: made of dead cells packed with keratin.

Accessory structures

________: originate in the dermis, extend through the epidermis to skin surface (hair follicles, exocrine glands, nails)

trigger inflammatory response

Repairing the integument: bleeding, swelling, pain; mast cells ________, a scab stabilizes and protects the area; macrophages clean the area; fibroblasts and endothelial cells divide producing granulation tissue.

Epidermis

________: stratified squamous epithelium, avascular, nutrients and oxygen diffuse from capillaries in the dermis.

Melanocytes

________: deep within epidermis, makes melanin, protection from UV damage.

soft fine

Types of hair: vellus hairs (________ hairs that cover most of the bodys surface) Terminal hairs (heavy, pigmented hairs on head, eyebrows, and eyelashes)

Melanoma

________: least common; melanocytes, spreading brown /black patches; quickly metastasizes to lymph and blood.

Keratinocytes

________: majority of cells, makes keratin, desmosomes.

Subcutaneous layer

________ (hypodermis): adipose tissue; deep to the dermis; connected to reticular layer by connective tissue; stabilizes position of the skin; large arteries and veins; fat.

Stratum Corneum

________: exposed surface of skin; 15 to 30 layers of keratinized cells; PROTECTS SKIN FROM ABRASION; exposed cells are shed after 2 weeks.

CELLS

________ OF EPIDERMIS: Keratinocytes, melanocytes, dendritic, tactile.

Tactile cells

________: sensory touch receptors.

Reticular Layer

________: dense irregular tissue; contains collagen fibers and elastic fibers; GIVES THE SKIN TOUGHNESS AND ELASTICITY.

cutaneous membrane

outer epidermis, inner dermis

Accessory structures

originate in the dermis, extend through the epidermis to skin surface (hair follicles, exocrine glands, nails)

Subcutaneous layer (hypodermis)

below the dermis

Epidermis

stratified squamous epithelium, avascular, nutrients and oxygen diffuse from capillaries in the dermis

CELLS OF EPIDERMIS

Keratinocytes, melanocytes, dendritic, tactile

Keratinocytes

majority of cells, makes keratin, desmosomes

Melanocytes

deep within epidermis, makes melanin, protection from UV damage

Dendritic cells

macrophages (WBC) immunity

Tactile cells

sensory touch receptors

Layers of keratinocytes from deepest to superficial

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

Stratum Basale

single row, actively mitotic, attached to basement membrane, forms a strong bond between the epidermis and dermis; has tactile cells (responds to touch) FORMS NEW KERATINOCYTES VIA MITOSIS

Stratum spinosum

the "spiny layer"; eight to ten layers of keratinocytes bound by desmosomes; cells appear spiny in histological sections; produced by division of cells in stratum basale, some of which continue dividing; contains dendritic cells which are active in immune responses

Stratum granulosum

three to five layers of keratinocytes; most cells stop dividing and produce keratin; forms dense granules, promotes cellular dehydration and cross-linking of keratin fibers; HELPS FORM KERATIN IN SUPERFICIAL LAYERS

Stratum lucidum

found only in thick skin; made of flat, dead keratinocytes

Stratum Corneum

exposed surface of skin; 15 to 30 layers of keratinized cells; PROTECTS SKIN FROM ABRASION; exposed cells are shed after 2 weeks

Dermis Layers

outer papillary layer and deeper reticular layer (80%)

Papillary layer

areolar tissue; contains capillaries, lymphatic vessels, and sensory neurons; PROVIDES NUTRIENTS TO SUPERFICIAL LAYERS

Reticular Layer

dense irregular tissue; contains collagen fibers and elastic fibers; GIVES THE SKIN TOUGHNESS AND ELASTICITY

Subcutaneous layer (hypodermis)

adipose tissue; deep to the dermis; connected to reticular layer by connective tissue; stabilizes position of the skin; large arteries and veins; fat

Immediate concerns for tissue damage

Dehydration (fluid loss), eloctrolyte imbalance, infenction

How do you evaluate the severity of burns

rule of nines (% of body burned due to estimate fluid loss)

Basal cell carcinoma

most common; stratum basale cells invade dermis and hypodermis; appears as shiny dome shaped nodules

Squamous cell carcinoma

stratum spinosum keratinocytes, appears as scaly red papules on scalp, ear, lips, hands; fast growing

Melanoma

least common; melanocytes, spreading brown/black patches; quickly metastasizes to lymph and blood

Hair structure

medulla (central core), cortex (intermediate layer), cuticle (surface layer)

Types of hair

vellus hairs (soft fine hairs that cover most of the bodys surface) Terminal hairs (heavy, pigmented hairs on head, eyebrows, and eyelashes)

Sabaceous glands

oil glands, discharge lipid secretion into hair follicles (lubricates and protects hair shaft); inhibits growth of bacteria

Approcrine sweat glands

found in armpits, around nipples, and pubic region; produce stinky, cloudy secretions

Eccrine sweat glands

glands that discharge directly onto the skin; widely distributed; secretions are 99 percent water plus salt

Ceruminous glands

produce earwax

Nails

made of dead cells packed with keratin

Repairing the integument

bleeding, swelling, pain; mast cells trigger inflammatory response, a scab stabilizes and protects the area; macrophages clean the area; fibroblasts and endothelial cells divide producing granulation tissue