CH 4 Integumentary System=skin and appendages

degrees of burns

-1st- epidermis damaged, temp discomfort -2nd- damage epidermis and upper dermis- blisters, no infection unless blister rupture (dermis open to environment- many vessels bacteria can travel) -1st and 2nd=partial thickness burn -3rd= full thickness burn- destroy entire skin- blackened area b/c nerves destroyed, regeneration not possible, blood plasma evaporate-fluid loss, pressure in vessels lower- cannot pump to brain-die, infections

malignant melanoma

-5% of skin cancers -arise from accumulated DNA damage in -if over 6mm-dangerous -resistance to immunotherapy and chemotherapy -melanocytes can divide quickly and have many mutations-travel through blood vessel and cause organ fails

recognize melanoma ABCDE rule

-Assymmetry-two sides of spot do not match -border irregularity- borders of lesions are not smooth- indentations -color-pigmented spot have different colors -diameter- larger than 6mm in diameter (size of pencil eraser

squamous cell carinoma

-arise from keratinocyte cells in stratum spinosum -lesions- scaly, reddened papule (small rounded elevated)- form shallow ulcer w/ raised borders -can metastasize to adj lymph nodes when not removed -sun induced -if caught early- surgery or radiation therapy- cure

skin cancer- carcinoma

-basal cell carcinoma-least malignant, do not usually migrate -cells of stratum basal proliferate and invade dermis and subcutaneous tissue -dome shaped nodule "pearly" beaded edge-surgically remove to heal

stratum lucidum

-dead translucent cells b/w granulosum and corner -only in thick skin- palms of hands and sole of feet -transition layer

hypodermis/subcutaneous tissue

-deep to reticular layer -made of adipose (fat)- nutrient storage -buffer between skin and muscle, anchor skin to underlying structure- allow skin to slide - prevent heat loss (insulates deeper tissue) -highly vascular- site of hypodermic injections -makes surgery dangerous- internal bleeding -not considered part of skin

reticular layer

-deepest skin layer -network of collagen and elastic fibers -collagen-toughness of dermis, attract and bind water-keep skin hydrated -elastic fiber- skin elasticity -stretch marks-when collagen tears -rich in nerve endings, blood vessels (body temp homeostasis), have hair roots, sweat and oil glands, pressure receptors-lamellar corpuscles -phagocytes endocytose bacteria that travel through epidermis

skin appendages

-derive from epidermis and extend to dermis -nails, hair, cutaneous glands- sebaceous and sweat glands

hair

-early humans- used as insulation from cold, now- only protection -produced by hair follicle-epithelial structure -enclosed by follicle=root, shaft- project from surface -hair forms- division of stratum basal epithelial cells in matrix(growth zone) of hair bulb-inferior end of follicle- go farther away from growing region- keratinized and die -medulla-central core of hair, surround by cortex layer-layers of flattened cells, surround by cuticle(most keratin)- single layer cells overlap like shingles- keep hair from matting -hair pigment-melanocytes in hair bulb -fastest growing tissue

cutaneous glands

-exocrine glands-release secretion to skin surface via ducts -sweat and sebaceous glands

dermis

-fibrous connective tissue -20% loose areolar tissue (papillary), 80% dense irregular tissue (reticular) -tension strength- keep skin from tearing -thermoregulation -highly vascularized and innervated -the leather of animals -2 layers- papillary and reticular

appendages: nails

-free edge, body (attached portion), root (embedded in skin), nail folds (skin overlap nail)- cuticle- edge of proximal nail fold -nail bed- stratum basal underneath -nail matrix-proximal area- responsible for nail growth- nail cells produce d by matrix- heavily keratinized and die -look pink b/c blood supply in dermis -lunule-white crescent

hair follicle

-inner epithelial root sheet form hair (made of epithelial tissue) -outer fibrous sheath- dermal connective tissue- supplies blood vessels (hair papilla) to epidermal portion-matrix in hair bulb -arrector pile-smooth muscle- connect each side of hair follicle to dermal tissue- contract when gold/frightened- hair upright

burns

-leading cause of accidental death -cell death, tissue damage caused by intense heat - body lose supply of fluids containing proteins and electrolytes- cause dehydration-shut down of kidney and circulatory shock- b/c low blood volume; fluids must be replaced immediately -heat loss- blood and heat brought to surface to heal cells faster- blood vessel always dilated -infections- lead cause of death, pathogens raid destroyed tissue and multiply, immune system is down

eccrine/mecrine gland

-most numerous -"true sweat"- clear secretion, primary water w/ salt, vitamin C, metabolic waste, lactic acid -sweat= acidic-inhibit growth of bacteria -regulate heat

papillary layer

-most superficial -made of loose areolar tissue- holds more fluid (blood), transfer nutrients and pick up waste from epidermis -dermal papillary- ejections into epidermis-give corrugated cardboard look, - house capillary roots (nutrient flow), pain and touch receptors, arranged in definite pattern (genetically determined)-create friction (grip)-friction ridges, and fingerprints

epidermis

-most superficial layer -made of thick stratified squamous epithelium -made of keratinocytes (most abundant) that make keratin-tough fiber -melanocytes- spider shaped cells found in stratum basale, produce melanin-put in melanosomes (sacs) and pushed out to keratinocytes -keratinocytes surround mealoncyte and take up melanin (store apical side) -melanin- allow for UV protection (harm dna), also digest melanin w/ lysosome- when go to apical side- karentincoyte are dead, no melanin, have sacs of keratin- give water proofing and protective property

sweat/ sudoriferous gland

-mostly water, pores lead to surface of skin -two types: eccrine and apocrine

sebaceous gland

-oily glands associated w/ hair follicles -oily product=sebum- secrete to upper third of hair follicle -oil b/c made of disrupted cells- lipids on PM -stimulated by hormones- acne- clogged sebaceous gland - pimple-infected pore, whitehead-not infected but clogged w/ sebum, black head=oxidized sebum -seborrhea- cradle cap in infants- overactivity of sebaceous glands

stratum corneum

-outermost layer (20 to 30 cells thick)- durable overcoat the protect cells underneath-waterproof -dead cell remnants- only keratin left

function of skin

-protect from heat, infection, chemicals, UV rays, cushions -waterproof barrier- keep water in and water out -insulator-regulate heat from body -sensory receptors

apocrine gland

-smelly parts- axillary/armpit and genital area -larger than eccrine gland -secretion contain fatty acids and proteins as well as substance from eccrine sweats -odorless, but when bacteria grow-more waste- smelly (fats are source of nutrients) -begin function by androgens (male sex hormones) during puberty -activated by nerve fibers during pain, stress and sex

stratum spinosum/ stratum granulosum

-stratum spinosum-healthy cells w/ dark nucleus -cells activity dividing, take up nutrients, make keratin -lose appearance of nucleus- looks more granular & flatter , more keratin,

layers of epidermis: stratum basal/ stratum germinativum slide 6

-stratum=layer of keratin -closest to dermis- skin stem cells located- allow regeneration of keratinoids, most nourished cells b/c nutrients diffuse from dermis -most cell division

integument

=epidermis+dermis+hypodermis