Mcgraw Hill Chapter 6 Integumentary System

integumentary system is made up of

skin

hair

nails

sweat glands

sebaceous glands

layers of integument

epidermis and dermis

the cutaneous membrane is

the most superficial region (skin)

the epidermis is

stratified squamous epithelium

the epidermis function is

absorption and secretion

protection from abrasion of stem cells

layers of epidermis in order from deep to superficial

stratum basale

stratum spinosum

stratum granulosum

stratum lucidum

stratum corneum

stratum basale

living layer

mitotic division of keratinocytes

melanocytes and tactile cells

stratum spinosum

has epidermal dendritic cells fight off infection

stratum granulosum

keratinocytes go through keratinization

stratum lucidum

found only in the thick skin

translucent layer of of eledin protein that fills the cell

stratum corneum

outermost layer of epidermis

20/30 layers dead keratinocytes

protects against abrasian

how long does it take for keratinocytes to go from stratum basale to the superficial surface and stratum corneum

25-45 days

difference between thick and thin skin

thick skin is only in palms of hands and soles of feet and have 5 layers of epidermis

thin skin is everywhere else and only has 4 layers of epidermis

what contributes to skin color

comes from melanocytes being more active in making more melanin from UV light

hemoglobin brings more oxygen to blood making it more red

carotene yellow orange pigment from vegetables

skin color changes from diagnostic value

cyanosis- blue oxygen deficiency

polar- pale decrease in blood flow

hematoma- bruising clots of blood under skin

erythema- blush increased blood flow

jaundice- yellowing from bilirubin release

common skin markings inlcude

nevus- mole overgrowth of melanocytes

freckles- increased spot of melanocyte activity

hemangiomas- birthmarks discoloration of benign blood vessel tumors

epidermis structure

Avascular dead outer layer

nourished by diffusion from capillaries of papillary layer of dermis

composed of cells arranged into strata (layers) and

separated from dermis by basement membrane

Dermis structure

vascular layer below epidermis

made of connective tissue layers

collagen and elastic fibers

sweat glands hair follicles

layers / structures found in the dermis

has hair follicles

nail roots in papillary layer

has papillae connecting to epidermal ridges

sebaceous glands

sweat glands

reticular layer of dense irregular ct has elastic and collagen fibers

purpose of dermal papilla

increase surface area b/w dermis and epidermis

increase amount of oxygen exchange

nourish avascular epidermis

give fingertips grasp

subcutaneous layer is

NOT part of the integument

below dermis

called hypodermis

drug injection site

highly vascularized increase rapid absorption

made of areolar and adipose ct

function of integumentary system

protection

prevention of water loss

metabolic regulation

secretion/absorption

immune function

sensory reception

structure / function of eponychium

cuticle

overlines nail root

protects epidermis from bacteria

thickened skin layer at base of nails

structure / function of free edge of nail

aid in grasping of fingers

protect digits

distal edge white part

structure / function of nail bed

epidermal layers deep to nail plate

structure / function of nail body

layer of compact high keratinized epithelial cells

protect digits

pink part

structure / function of nail matrix

mitotic cells correspond to stratum basale

growth zone of nail

structure / function of nail root

smallest part

in nail plate under the nail

growth of nail

structure / function of lunula

part of nail matrix

crescent shape at bottom of nail

shapes outermost part of nail

strcuture / function of nail folds

folds of skin overlapping nail

structure / function of hyponychium

thickened stratum corneum under where free nail edge hangs

functions of hair (6)

protection

facial expression

heat retention

sensory reception

visual identification

chemical signal dispersal

structure of hair bulb

surrounds hair papilla

made of ct

only living region of epithelial cells

structure of hair root

zone of hair from bulb to skin surface

structure of hair shaft

portion of hair beyond skin surface no nerve endings

has cuticle

medulla

cortex

image of hair coretex medulla epithelial root sheath connective tissue root sheath

arector pili muscle

ribbons of muscle from hair follicle to dermal papillae causing goosebumps bc of hair elevation contractions

Stages of hair growth

Anagen (Growth stage)

Catagen (Transition/regression stage)

Tetagen (Final resting stage)

basis for hair color and texture

hair color- synthesis of melanin lightening w age to gray

hair texture- circle is straight, oval is wavy, flat is curly

types of sweat glands

merocrine sweat glands- thermoregulation sweat on surface of skin

apocrine sweat glands- body odor during adolescence

function / location of sebaceous glands

they secrete oil

lubricate cover hair follicle and skin with sebum for protection

ceruminous glands

modified apocrine sweat gland

located in external ear canal

secretes cerumen (earwax)

mammary glands

modified apocrine sweat glands of breasts that produce milk

regeneration is

replacement of damaged/dead cells with same type of cell restoring function

fibrosis is

gap filled with scar tissue bc collagen makes fribroblasts

functional activity is NOT restored

third degree burns are determined by

invasion of the epidermis, dermis, and subcutaneous layer

needs skin grafts

severe scarring

burns are dangerous and disrupt the body's homeostatic mechanisms by

causing dehydration from water loss

infection and sepsis

no protective barrier

electrolyte imbalance

slows thermoregulation

treatments of burns include

managing fluids

relieve swelling

remove dead tissue

control infection

increase caloric intake

skin grafting for third degree burns

effects of aging on the integumentary system

1 decrease in number of stem cell activity

2 decrease in collagen fibers

3 elastic fibers lose elasticity-crease lines make wrinkles

4 decrease in immune response bc dendritic cell lower and hair follicles make few to none

5 UV radiation damages DNA in epidermal cells causing skin cancer

basal cell carcinoma

Most common form of skin cancer

Originates in stratum basale due to mutations caused by overexposure to UV radiation

squamous cell carcinoma

Type of skin cancer more serious than basal cell carcinoma

uncontrolled overgrowth of abnormal squamous cells

malignant melanoma

Most serious form of skin cancer; often characterized by black or dark brown patches on the skin

caused by melanocytes

Clinical View: UV Radiation , Sunscreens, and Sunless Tanners

sun makes UV radiations

sunscreen blocks UVA/B rays

sunless tanner stains skin no increase in melanin

*Clinical View: Nail Disorders

nails show overall health

brittle nails- separate nail plate bed

ingrown nails- nail digs into skin

yellow nail syndrome- growth/thickening slows

onchomycosis- fungal infection

Beau's lines- temp interference w/ nail growth

*Clinical view: Acne and treatments

acne- plugged sebaceous ducts

during puberty

increase activity of gland secretion

blocks pores

treatments- salycilic acid, antibiotics, vitamin A, benzoyl peroxide

Clinical View: Burns

death caused by heat radiation chemicals sunlight

threat to life from fluid loss and dehydration infection

*Clinical view: Botox and wrinkles

botox- treatment for wrinkles of facial muscle expression

blocks nerve impulses to facial muscles

injected to superficial facial muscles temporary

muscles regain function