Integumentary System (CH 6) - Weebly fileIntegumentary System (CH 6) Cutaneous Membrane (skin)...
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Transcript of Integumentary System (CH 6) - Weebly fileIntegumentary System (CH 6) Cutaneous Membrane (skin)...
Integumentary System (CH 6) Cutaneous Membrane (skin)
contains the following tissues
Stratified squamous epithelium Glandular epithelium Dense irregular connective Adipose connective Smooth muscle Nervous
7 FUNCTIONS 1. Protection
from water loss, injury, chemicals, and microorganisms pH level of 56 to prevent microorganism growth
Langerhans cells (epidermis) Type of white blood cell; assimilates, processes, and carries antigens(a
toxin/foreign substance) to nearest lymph node for further immune system processing
Macrophages and mast cells (dermis) Immune system
2. Excretion urea + uric acid through sweat
3. Regulation of body temp. (negative feedback mechanism) stimulus → receptors(receive) → control center → effectors (exit) → response
Hyperthermia → abnormally high Hypothermia → abnormally low
4. Sensory reception Light touch = Meissner's corpuscles
dermal papillae concentrated in fingertips, palms, soles, eyelids, tip of the tongue
and genitals Pressure detection = Pacinian corpuscles
dermis and subcutaneous region 5. Contains immune system cells
Keratinocytes → stimulates white blood cell production Langerhans cells + macrophages Interacts with Thelper cells (suppress/stimulation of immune system)
6. Synthesizes vitamin D
needed for bone/tooth development 7. Acts as a blood reservoir
dermis houses 10% of body’s blood vessels skin requires 12% of body’s blood
AGED SKIN Skin becomes scaly Age spots appear Epidermis thins Dermis reduces Loss of fat Wrinkling Sagging Sebaceous glands secrete less oil Melanin production slows Hair thins Number of hair follicles decrease Nail growth becomes impaired Sensory receptors decline Body temp. unable to be controlled Diminished ability to activate Vitamin D
2 LAYERS OF SKIN
1. Epidermis Keratinized (dead/fibrously structured cells) stratified squamous epithelium Avascular Melanocytes (produce melanin = skin color) Thickest on palm + soles (most friction 0.81.4 mm)
Layers of the Epidermis Characteristics
Stratum Corneum Many layers of keratinized epithelial cells (flattened
with no nucleus b/c dead)
Stratum Lucidum Cells appear clear; nuclei, organelles and cell membrane are no longer visible
Stratum Granulosum 35 layers of flattened granular cells; contain shrunken fibers of keratin and shriveled nuclei
Stratum Spinosum Many layers of cells w/ centrally located large, oval nuclei + developing fibers of keratin; cells become flattened
Stratum Basale single row of cuboidal/ columnar cells (dividing and growing) + melanocytes
2. Dermis
12mm thick on average FUNCTIONS → bind epidermis + underlying tissue & nourish the epidermis muscle cells, sensory receptors, blood vessels, hair follicles, and glands
Layers of Dermis Characteristics
Papillary 20% loose connective tissue + papillae (fingerlike projections EX: forms fingerprints) + Meissner corpuscles
Reticular 80% dense connective tissue + bundles of collagen, elastic, and reticular fibers (gives skin strength + resilience) + Pacinian corpuscles
Accessory Structures
Hair follicles epidermal cells tubelike depression extends into dermis hair root + shaft + papilla dead epidermal cells melanin arrector pili muscle
Nails
nail plate + bed + lunula
Sebaceous glands (oil)
usually associated with hair follicles holocrine glands + sebum secretion NONE on palms and soles
Sudoriferous Glands (sweat)
widespread on skin originates in deeper dermis or hypodermis eccrine + apocrine +ceruminous + mammary
SUBCUTANEOUS LAYER/ HYPODERMIS (Beneath the Skin)
loose connective + adipose insulates contains major blood vessels
SKIN COLOR
Genetic Factors varying amounts of melanin + granules (thicker/ bigger = darker) albinos have no melanin
Environmental Factors sunlight + UV light + X rays = darker melanin
Physiological Factors dilation of dermal blood vessels constriction of dermal blood vessels accumulation of carotene Jaundice (yellowing)
HEALING CUTS
CLINICAL APPLICATION
Epidermolysis Bullosa hereditary (two recessive genes from each parent make it) children born with inability to produce collagen7 protein
lacking glue that binds inner and outer layer of skin together skin just tears apart (like velcro failure)
Acne Vulgaris MOST COMMON SKIN DISORDER sebum + epithelial cells clog glands anaerobic bacteria trigger inflammation
whiteheads + blackheads hormonally induced androgens stimulate sebum production treatment → antibiotics, topical creams, or birth control pills
Athlete’s Foot (moist environments + spread by contact) fungal infection
skin + toes + soles Ringworm (moist environments + spread by contact)
fungal infection ring pattern
Birthmark (Nevus) over 80% babies have one 2 TYPES
Vascular Pigmented
common types are café au lait spots, moles, portwine stains, Mongolian spots, and hemangiomas
rare = tumor growth or disfigurement
Boil = bacterial infection of skin Carbuncles = bacterial infection spread into subcutaneous tissue Eczema
noncontagious blistering, crusting, bleeding, scaling, oozing, and itching some are hereditary
Psoriasis skin growth of abnormally high rate
red patches + silvery scales related to immune system can be hereditary
Cancer (skin) Carcinomas
MOST COMMON TYPE OF SKIN CANCER epithelial cells squamous/basal types treatment → surgical removal
Melanomas melanocytes harder to treat tanning bed increase = increase in last 20 yrs
Rule of Nine (burns)
1st degree (superficial partialthickness burn) only epidermis
edema (swelling) +shedding area = red heal w/ no scar
2nd degree (deep partialthickness burn) epidermis + dermis
fluid escapes from capillaries and collects in epidermal cells = blistering area = red/ waxy white usually heals w/o scarring
3rd degree (fullthickness burn) epidermis + dermis + accessory structures
area = leathery/red/black/white skin grafts often necessary (autograft or homograft) scarring will occur