Chapter 5 The IntegumentarySystem Flashcards

Question

Stratum Lucidum

Answer 1

Narrow layer of clear, dead keratinocytes; only in thick skin

Answer 2

Outermost layer; several layers of dead, flattened keratinocytes with thickened plasma membrane

Answer 3

–Keratinocytes begin life in stratum basale or spinosum; pass through each epidermal layer; shed from stratum corneum –Migration from deepest strata to stratum corneum takes 40−50days to complete

Answer 4

In stratum spinosum; phagocytes of immune system; protect skin and deeper tissues from pathogens

Answer 5

Oval cells scattered throughout stratum basale; sensory receptors associated with small neurons in dermis: –Detect light touch and discriminate shapes and textures –Large numbers in regions specialized for touch: fingertips, lips, and at base of hairs

Answer 6

In stratum basale; produce melanin (protein pigment ranging from orange-red to brown-black

Answer 7

– about as thick as paper towel; all five epidermal layers and very thick stratum corneum; no hair follicles; many sweat glands

Answer 8

–covers areas of body not subjected to as much mechanical stress; about as thick as sheet of printer paper; only four layers (no stratum lucidum) –Each layer is thinner than those of thick skin –Numerous hairs, sweat glands, and sebaceous glands present

Answer 9

– additional layers of stratum corneum; forms in either thick or thin skin in response to repetitive pressure

Answer 10

– highly vascular layer deep to epidermis *Functions: –Provides blood supply for epidermis –Contains sensory receptors –Anchors epidermis in place *Composed of two distinct layers; two types of connective tissue 1. Papillary Layer 2. Reticular Layer

Answer 11

Thinner, most superficial of two layers *Loose connective tissue *Special collagen fibers at dermis-epidermal junction; extends into epidermal basement membrane; anchors epidermis to dermis

Answer 12

Tiny projections at surface of papillary layer where it contacts epidermis: –Contain tiny blood vessels (capillaries) arranged in loops; extend up into most superficial part of dermal papillae –Allow oxygen and nutrients to diffuse into extracellular fluid of dermis, then into avascular epidermis

Answer 13

Also in dermal papillae; sensory receptors; respond to light touch stimuli -skin of fingertips, lips, face, and external genital

Answer 14

*Collagen bundles strengthen dermis; prevent traumatic injuries from damaging deeper tissues *Elastic fibers allow dermis to return to its original shape and size after stretching *Rich in proteoglycans that draw water into ground substance; keeps skin firm and hydrated *Blood vessels, sweat glands, hairs, sebaceous glands, and adipose tissue are also present

Answer 15

Sensory receptors embedded within reticular layer; respond mainly to changes in pressure and vibration

Answer 16

Small visible lines in epidermis created by interaction between dermis and epidermis; best seen in thick skin

Answer 17

Areas where dermal papillae are more prominent due to presence of thick collagen bundles *Indent overlying epidermis to create epidermal ridges; enhance gripping ability of hands and feet: –Occur in characteristic patterns; loops, arches, and whorls; genetically determined and unique to each person –Sweat pores open along ridges; leave thin film or fingerprint on things touched with fingers

Answer 18

–indentations in epidermis from gaps between collagen bundles in dermis

Answer 19

–deep creases in areas of body (surrounding joints) where reticular layer is tightly anchored to deeper structure

Answer 20

Bacterial toxin; temporarily paralyzes facial muscles; causes skin to appear smoother

Answer 21

Adipose tissue, collagen, and/or proteoglycans injected into wrinkles

Answer 22

(especially nonprescription) claim to reduce appearance of wrinkles; little to no effect

Answer 23

Skin color – mostly determined by various amounts of melanin: *Produced by melanocytes in stratum basale *Composed of two molecules of amino acid tyrosine, occurs in stepwise fashion within special vesicle (melanosome) *Primary function – protecting keratinocyte DNA from mutations induced by UV radiation

Answer 24

Melanin synthesis increases with exposure to natural or artificial UV radiation - has both immediate and delayed effects on skin pigmentation

Answer 25

Oxidation of melanin already present in keratinocytes; causes melanin to quickly darken

Answer 26

UV light causes DNA damage in melanocytes; stimulates melanin production; appears within 72 hours; lasts longer than melanin oxidation

Answer 27

–Amount of UV radiation melanin can absorb is limited as is the protection provided –People of all skin pigmentations can develop sunburns and are at risk for skin cancers

Answer 28

Small area of increased pigmentation; increased melanin production in local spot

Answer 29

Area of increased pigmentation, caused by local proliferation of melanocytes; not an increase in melanin production

Answer 30

Melanocytes fail to manufacture tyrosinase; results in lack of skin pigmentation and greatly increased risk of keratinocyte DNA damage from UV radiation

Answer 31

Yellow-orange pigment in food items such as egg yolks and orange vegetables –Lipid-soluble molecule; accumulates in stratum corneum –Imparts slight yellow-orange color; particularly visible in stratum corneum of thick skin

Answer 32

In red blood cells; iron-containing protein; binds to and transports oxygen throughout body -Gives blood characteristic color

Answer 33

blood flow in dermis increases; makes skin more reddish -Other conditions causing erythema include trauma, fever, and infection

Answer 34

Blood flow in dermis decreases; results in loss of normal pinkish hue; most visible in pale-skinned individuals; epidermis takes on whitish color of collagen in dermis

Answer 35

Sign that someone needs immediate attention; hemoglobin has very low levels of bound oxygen; blood turns reddish purple; skin takes on faint bluish hue; can occur when: –someone has difficulty breathing –hemoglobin or red cell levels are low in blood –hemoglobin is unable to bind to oxygen

Answer 36

Include hair, nails, and glands

Answer 37

Small filamentous structures; protrude from surface of skin over entire body except in regions with thick skin, lips, and parts of external genitalia

Answer 38

–Provides protection by preventing substances and organisms from entering eyes and nose –Protects underlying skin of scalp from UV radiation and mechanical trauma –Associated with small sensory neuron; plays role in detecting changes in environment

Answer 39

Composed of Shaft and Root. Made of: stratified squamous keratinized epithelial cells

Answer 40

▪Portion of hair projecting from skin’s surface ▪Made of columns of dead keratinized epithelial cells that have completed keratinization process

Answer 41

▪Segment of hair embedded in dermis; surrounded by small sensory neuron ▪Indented at base by projection of blood vessels from dermis (hair papilla) ▪Root and hair papilla collectively known as hair bulb ▪Many epithelial cells in root are still alive; have not completed keratinization process

Answer 42

Small number of keratinocytes at base of root; actively divide

Answer 43

-Inner Medulla -Middle Cortex -Outermost cuticle

Answer 44

Soft core only found in thick hair (head); composed of soft keratin

Answer 45

Highly structured and organized with several layers of keratinocytes containing hard keratin; provides strength

Answer 46

Single layer of over lapping keratinocytes containing hard keratin; provides mechanical strength

Answer 47

surrounds epithelial root; consists of connective tissue; supports follicle and keeps it separate from dermis

Answer 48

Small bands of smooth muscle; attach to dermal root sheath on one end and dermal papillary layer on other

Answer 49

Causes hair to: -stand up (piloerection), gives skin dimpled appearance (“goosebumps”)

Answer 50

1. Growth stage 2. Resting stage

Answer 51

Mitosis occurs in matrix ▪Cells divide and push cells above them farther away from blood supply; keratinize and die ▪Stage varies in duration from a month to as long as six years; depends on location of hair

Answer 52

Mitosis in matrix ends as cells die ▪Follicle shortens; hair is pushed toward surface where it remains dormant for a month or two ▪Falls out on its own or is pushed out by new hair in growth stage

Answer 53

Thin, non pigmented hair covering nearly entire body of fetus; generally fall out around birth; replaced with one of two hair types: ▪Terminal hair ▪Vellus hair

Answer 54

Thick, coarse, and pigmented hair; surrounding eyes and on scalp -replaces much of vellus hair after puberty; varies by gender; more hair replacement occurs in males than female

Answer 55

Thinner non pigmented hair; over remaining regions of body

Answer 56

▪Blond hair – little melanin ▪Black hair – contains lots of melanin ▪Red hair – special reddish pigment containing iron –Melanocytes produce less melanin with aging so hair eventually turns gray or white

Answer 57

Hard accessory structures at ends of digits; composed of stratified squamous epithelium filled with hard keratin

Answer 58

Most visible component of nail; on top of underlying epidermal nail bed; divided into: 1. Nail Body 2. Nail root

Answer 59

visible portion of nail plate

Answer 60

portion of plate under skin; location of nail matrix containing actively dividing cells

Answer 61

on proximal edge covering nail root; distal edge of fold is eponychium (cuticle); consists of only stratum corneum

Answer 62

on medial and lateral edges of nail plate respectively

Answer 63

attached to underlying nail bed by accumulation of stratum corneum called hyponychium

Answer 64

Occurs at nail matrix –Actively dividing cells push neighboring cells distally –Die once keratinization is completed and have been cut off from blood supply –Grow an average of 0.5mm per week; toenails grow more slowly

Answer 65

*Do not contain melanocytes; mostly translucent except at lunula; half-moon shaped region of proximal nail plate; represents accumulation of keratin *Primary function – protection of underlying tissue (distal tips of fingers and toes) from trauma; can be used as tools; enables more precise gripping of items

Answer 66

Derived from epidermal cells; located deeper in dermis: *Sweat (sudoriferous) glands – produce sweat *Sebaceous glands – produce oily sebum

Answer 67

Differ structurally and in products secreted; all secrete products via exocytosis (merocrine secretion): 1. Eccrine 2. Apocrine 3. Ceruminous 4. Mammary Glands

Answer 68

▪Most prevalent type ▪Simple coiled tubular glands in dermis ▪Sweat contains mostly water, waste products, and electrolytes ▪Exits from duct through sweat pore onto epidermal surface

Answer 69

▪Found in specific regions of body such as axillae, anal area, and areola ▪Large glands; release protein-rich secretion into hair follicle ▪Secretions become odoriferous once skin bacteria metabolize contents ▪Influenced by sex hormones; become active after puberty

Answer 70

▪Modified apocrine glands ▪Release thick secretion called cerumen (ear wax) into hair follicles in ear ▪Cerumen traps incoming particles along tube leading to tympanic membrane; also lubricates

Answer 71

highly specialized sweat glands; produce modified sweat (milk)

Answer 72

Branched with clusters of secretory cells (acini) surrounded by small ducts; converge to form central duct that empties into hair follicle or small pore; make and secrete sebum

Answer 73

–Everywhere on body except palms and soles; greatest number on face and scalp –Secretion is influenced by sex hormones, especially male hormone (testosterone) –Dramatic increase in sebum production occurs after puberty –Contains cellular fragments and debris in addition to lipids –Coats hair, providing it with hydrophobic barrier; inhibits water loss –Also inhibits growth of or kills certain bacteria

Answer 74

Waxy, oily mixture of mostly lipids; released by holocrine secretion; secretory cells accumulate sebum until cell ruptures

Answer 75

Accumulation of sebum and dead cells within sebaceous glands; produces comedone (blackhead); occasionally becomes infected by Propionibacterium acnes; causes inflammation and formation of pustule (pimple)

Answer 76

Common skin pathology; defined as any disruption in skin’s integrity; includes –Lacerations (cuts) –Burns –Skin cancers

Answer 77

Wounds caused by heat, extreme cold, electricity, chemicals, and radiation; classified according to extent and depth of tissue damage: 1. First degree 2. Second degree 3. Third degree

Answer 78

–Minor wounds; only damage epidermis –Skin may develop erythema (redness) and some mild pain without any permanent damage

Answer 79

–Involve epidermis and part or all of dermis –Can result in pain, blistering, and scarring

Answer 80

–Most damaging wounds –Involve epidermis, dermis, hypodermis, potentially even deeper tissue (muscle or bone) –Not generally painful at first because nerves too are destroyed –Typically major tissue damage and significant scarring; loss of hair follicles; diminished or absent keratin production –Problems with dehydration due to massive fluid loss from swelling; also great risk for infection

Answer 81

*Method for estimating how much of body has been affected by burn *Body is divided into 11 areas; each represents 9% of total body area *Useful clinical tool for grading extent of burn; severity and extent of burn are used to direct treatment options

Answer 82

One of the most common diseases in the world; caused by mutations in DNA; induces cell to lose control of cell cycle

Answer 83

Unchecked cell division eventually leads to formation of large population of undifferentiated cells

Answer 84

Tumor cells spread through blood or lymphatic vessels to other tissues and continue to divide

Answer 85

–cancer-inducing chemicals, toxins, or agents called carcinogens –forms of radiation

Answer 86

–Most common of all cancer types–Arises from keratinocytes in stratum basale of epidermis –Skin regularly exposed to UV radiation is at risk for developing these tumors –Appears as nodule with a central crater –Rarely metastasizes to other tissues –Can be resolved successfully with surgical removal

Answer 87

–Second most common skin cancer–Cancer of keratinocytes of stratum spinosum –Scaly plaques may ulcerate and bleed; usually on head and neck –Tumors are more likely to metastasize than basal cell carcinoma; surgical removal is still useful

Answer 88

Cancer of melanocytes –Early detection of melanoma is critical due to tendency to metastasize –“Arms” of cancerous melanocytes extend down into dermis and access dermal blood vessels; enables cells to spread to other tissues via bloodstream –Treated with surgical removal; possibly radiation therapy and chemotherapy –Prognosis depends on size of tumor, depth to which it extends into dermis, and whether it has metastasized to other tissues

Answer 89

Can distinguished from other skin cancers and normal moles using ABCDE rule: –(A): Asymmetrical shape (two sides do not match) –(B): Border irregularity –(C): Color, usually blue-black or a variety of colors –(D): Diameter generally larger than 6 mm (size of a pencil eraser) –(E):Evolving (changing) shape and size