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59 Cards in this Set
- Front
- Back
The integument |
1. is the largest system of the body 2. sixteen percent of body weight 3. 1.5 to 2m2 in area |
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the integument is made up of two parts |
1. Cutaneous membrane (skin) 2. Accessory structures |
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two components of the cutaneous membrane |
1. outer epidermis ( superficial epithelium-epithelial tissues) 2. inner dermis (connective tissues) |
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Accessory structure |
1. originate in the dermis 2. extend through the epidermis to skin surface (Hair, Nails, Multicellular exocrine glands) |
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connections |
1. cardiovascular system 2. blood vessels in the dermis |
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Nervous system |
sensory receptors for pain, touch, and temperature |
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Hypodermis (superficial fascia or subcutaneous layer) |
1. loose connective tissue 2. below the dermis 3. location of hypodermic injections |
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Functions of skin |
1. protection of underlying tissues and organs 2. excretion of salts, water, and organic wastes (glands) 3. maintenance of body temperature (insulation and evaporation) 4. production of melanin |
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functions of skin |
1. production of keratin 2. synthesis of vitamin D3 3. storage of lipids 4. detection of touch, pressure, pain, and temperation |
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the Epidermis |
1. is avascular stratified squamous epithelium 2. nutrients and oxygen diffuse from capillaries in the dermis |
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Keratinocytes (cells of the epidermis) |
1. contain large amounts of keratin 2. are the most abundant cells in the epidermis |
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Thin skin |
1. covers most of the body 2. has four layers of keratinocytes |
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Thick skin |
1. covers the palms of the hands and soles of the feet 2. has five layers of keratinocytes |
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5 strata layers in order from the bottom |
1. stratum basale 2. stratum spinosum 3. stratum granulosum 4. stratum lucidum 5. stratum corneum |
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stratum basale |
1. attached to basement membrane by hemidesmosomes 2. forms strong bond between epidermis & dermis 3. forms epidermal ridges ( basis of fingerprints) 4. dermal papillae ( tiny mound) . increase the area of basement membrane . strengthen attachment between epidermis and dermis 5. has many basal cells, or germinative cells |
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Special cells of stratum basale are: |
1. Merkel cells 2. Melanocytes
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Merkel cells |
Found in hairless skin respond to touch (trigger nervous system |
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Melanocytes |
Contain the pigment melanin Scattered throughout stratum basale |
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Stratum spinosum (the "spiny layer") |
1. produced by division of stratum basale 2. 8-10 layers of keratinocytes bound by desmosomes 3. cells shrink until cytoskeletons stick out (spiny) 4. continue to divide, increasing thickness of epithelium 5. contain dendritic (Langerhans) cells, active in immune response
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Stratum granulosum ( the "grainy layer") |
1. stops dividing, starts producing a) keratin . a tough, fibrous protein . makes up hair and nails b) keratohyalin . dense granules . cross-link keratin fibers
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Karatin |
tough, fibrous protein makes up hair and nails |
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Cells of stratum granulosum |
1. produce protein fibers 2. dehydrate and die 3. create tightly interlocked layer of keratin surrounded by keratohyalin |
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Stratum lucidum ( the " clear layer") |
1. found only in thick skin 2. covers the stratum granulosum |
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Stratum corneum (the "horn layer") |
1. exposed surface of skin 2. 15 to 30 layers of keratinized cells 3. water resistant 4. shed and replaced every two weeks |
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Keratinization |
1. the formation of layer of dead, protective cell filled with keratin 2. occurs on all exposed skin surfaces except eyes 3. skin life cycle 4. it takes 7 to 10 days for a cell to move from stratum basale to stratum corneum |
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types of perspiration |
1. insensible perspiration 2. sensible perspiration |
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Insensible perspiration |
interstitial fluid lost by evaporation through the stratum corneum |
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Sensible perspiration |
1. water excreted by sweat glands 2. dehydration results a) form damage to stratum corneum (e.g., burns and blisters[insensible perspiration]) b) form immersion in hypertonic solution (e.g. seawater [osmosis]) |
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Skin color is influenced by two pigments |
1. carotene 2. melanin . blood circulation (red blood cells) |
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Carotene |
1. orange-yellow pigment 2. found in orange vegetables 3. accumulates in epidermal cells and fatty tissues of the dermis 4. can be converted to vitamin A |
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Melanin |
1. yellow-brown or black pigment 2. produced by melanocytes in stratum basale 3. stored in transport vesicles (melanosomes) 4. transferred to keratinocytes |
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function of Melanocytes |
1. melanin protect skin from sun damage 2. ultraviolet (UV) radiation a) causes DNA mutations and burns that lead to cancer and winkles 3. skin color depends on melanin production, not number of melanocytes |
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The dermis |
1. located between epidermis and subcutaneous layer 2. anchors epidermal accessory structures (hair, follicles, sweat glands)
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Dermis consists of two components |
1. outer papillary layer 2. deep reticular layer |
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Skin damage |
1. sagging and winkles(reduced skin elasticity) are caused by a) dehydration b) age c) hormonal changes d) uv exposure |
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Stretch marks |
1. thickened tissue resulting from excessive stretching of skin due to a) pregnancy b) weight gain |
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Cleavage line |
1. collagen and elastic fibers in the dermis a) arranged in parallel bundles b) resist force in a specific direction 2. cleavage (tension) lines establish important patterns a) a parallel cut remains shut, heals well b) a cut across (right angle) pulls open and scars |
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the dermal blood supply |
1. cutaneous plexus a) a network of arteries along the reticular layer 2. papillary plexus a) capillary network from small arteries in papillary layer 3. venous plexus a) capillary return deep to the papillary plexus 4. contusion a) damage to blood vessels resulting in "black-and-blue" bruising |
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Nerve fibers in skin control |
1. blood flow 2. gland secretions 3. sensory receptors a) light touch-tactile corpuscles, located in dermal papillae b) deep pressure and vibration-lamellated corpuscles, in the reticular layer |
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The Hypodermis (subcutaneous layer) |
1. lies below the integument 2. stabilizes the skin 3. allows separate movement 4. made of elastic areolar and adipose tissues 5. connected to the reticular layer of integument by connective tissue fibers 6. few capillaries and no vital organs 7. the site of subcutaneous injections using hypodermis needles |
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Hair, hair follicles, sebaceous glands, sweat glands, and nails are: |
1. integumentary accessory structures 2. derived from embryonic epidermis 3. located in dermis 4. project through the skin surface |
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Functions of hair |
1. protects and insulates 2. guards opening against particles and insects 3. is sensitive to very light touch |
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Hair follicle |
1. located deep in dermis 2. produces nonliving hairs 3. wrapped in a dense connective tissue sheath 4. base is surrounded by sensory nerves(root hair plexus |
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Accessory structures of hair |
1. Arrector pili a) involuntary smooth muscle b) causes hairs to stand up c) produces "goose bumps" 2. Sebaceous Glands a) lubricate the hair b) control bacteria |
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Regions of the hair are: |
1. hair root a) lower part of the hair b) attached to the integument 2. hair shaft a) upper part of the hair b) not attached to the integument |
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Hair shaft structure are: |
1. Medulla a) the central core 2. Cortex a) the middle layer 3. Cuticle a) the surface layer |
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Keratin in hair |
1. as hair is produced, it is keratinized 2. medulla contains flexible soft keratin 3. cortex and cuticle contain stiff hard keratin |
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Exocrine glands in skin |
sebaceous glands (oil glands) . holocrine glands . secrete sebum |
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two types of sweat glands |
1. apocrine glands 2. merocrine (eccrine) glands . watery secretions |
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Apocrine sweat glands |
1. found in armpits, around nipples, and groin 2. secret products into hair follicles 3. produce sticky, cloudy secretions 4. break down and cause odors 5. surrounded by myoepithelial cells . squeeze apocrine gland secretions into skin surface . in response to hormonal or nervous signal
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Merocrine (Eccrine) sweat glands |
1. widely distributed on body surface 2. especially on palms and soles 3. coiled, tubular glands 4. discharge directly into skin surface |
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Nails |
1. protect fingers and toes 2. made of dead cells packed with keratin 3. metabolic disorders can change nail structure |
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Nail production |
occurs in a deep epidermal fold near the bone called the nail root |
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structure of a nail |
1. skin beneath the distal free edge of the nail . is the hyponychium (onyx=nail) 2. visible nail emerges . from the eponychium (cuticle) . at the tip of the proximal nail fold |
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Effects of aging |
1. reduced blood supply 2. decreased function of hair follicles 3. reduction of elastic fibers 4. decreased hormone levels 5. slower repair rate |
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Papillary layer |
1. consists of areolar tissue 2. contains smaller capillaries, lymphatics, and sensory neurons 3. has dermal papillae projecting between epidermal ridges |
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Reticular layer |
1. consists of dense irregular connective tissue 2. contains larger blood vessels, lymphatic vessels, nerve fibers 3. contains collagen and elastic fibers 4. contains connective tissue proper |
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Dermatitis |
1. an inflammation of the papillary layer 2. caused by infection, radiation, mechanical irritation, or chemicals (e.g. poison ivy) 3. characterized by itch or pain |
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(dermal strength and elasticity) presence of two types of fibers: |
1. collagen fibers a) very strong, resist stretching but bend easily b) provide flexibility 2. elastic fibers a) permit stretching and then recoil to original length b) limit the flexibility of collagen fibers to prevent damage to tissue 3. skin turgor a) properties of flexibility and resilience |