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A&P > Week 3- Integumentary System > Flashcards

Week 3- Integumentary System Flashcards

1
Q

Integument

A

-Skin covering your body
-body’s largest organ
-surface epithelium protects underlying body layer
-connective tissue that is deep to epithelium provides strength and resilience
-also contains smooth muscle associated with hair follicles (arrector pili)
-nervous tissue detects and monitors sensory stimuli (touch, pressure, temp, and pain)
-7-8% of body weight and about 1.5-2 square meters
-2 layers:
1) epidermis
2) dermis

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2
Q

Cutaneous membrane

A

Another word for skin

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3
Q

Integumentary System

A

-Consists of the skin and its derivatives: nails, hair, sweat glands, and sebaceous (oil) glands

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4
Q

What does every square inch of skin contain on average?

A

up to 20 feet of blood vessels, 650 sweat glands, 100 sebaceous glands, and over 100 nerve endings

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5
Q

What can the skin do?

A

-acts as barrier to outside world
-subjected to trauma, harmful chemical, pollutants, microbes, and damaging sunlight
-changes in color may reflect body disorders or anomalies
-skin changes and lesion sometimes reflect systemic infections or disease

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6
Q

Dermatology

A

Scientific study and treatment of integumentary system

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7
Q

Epidermis

A

-keratinized, stratified squamous epithelial tissue
-0.075-0.6 mm thick

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8
Q

Layers of epidermis (Superficial to deep)

A

1) Stratum corneum
2) Stratum lucidum (only in thick skin)
3) Stratum granulosum
4) Stratum spinosum
5) Stratum basale

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9
Q

Stratum corneum

A

-“horny layer”
-most superficial layer of epidermis
-20-30 layers of dead, scaly, interlocking, keratinized cells
-dead keratinocytes are anucleated (lacking nucleus) and tightly packed
-cells contain large amount of keratin
-keratinocytes are made in stratum basale and move up to stratum corneum where they are sloughed off
-thickened surface as well as exocrine secretions help prevent growth of microorganisms

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10
Q

Stratum lucidum

A

-“clear layer”
-2-3 keratinocyte layers, cells are pale and flattened
-deep to stratum corneum
-ONLY IN THICK SKIN
-helps protect from UV light

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11
Q

Stratum granulosum

A

-“granular layer”
-3-5 layers of keratinocytes superficial to stratum spinosum
-process of keratinization begins (keratinocytes synthesize significant amounts of keratin)
-accumulation of keratin causes both nucleus and organelles to disintegrate which results in death of these cells

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12
Q

Stratum spinosum

A

-keratinocytes attach to their neighbors by many membrane junctions called desmosomes (which provide structural support between cells of epidermis)
-also contains epidermal dendritic cells

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13
Q

Epidermal dendritic cells

A

-immune cells are immune cells that help fight infection in epidermis
-present in stratum spinosum and stratum granulosum
-phagocytic activity initiates immune response to protect body against pathogens that have penetrated superficial epidermal layers as well as epidermal cancer cells

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14
Q

Stratum Basale

A

-deepest epidermal layer
-“basal layer”
-single layer of cuboidal/columnar cells attached to underlying basement membrane that separates epidermis from dermis

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15
Q

3 Cell Types of Stratum Basale

A

1) Keratinocytes
2) Melanocytes
3) Tactile/Merkel cells

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16
Q

Keratinocytes

A

-most abundant cell type in epidermis
-stem cells divide to generate new keratinocytes that replace dead ones shed from surface
-gives skin its strength and makes epidermis water resistant

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17
Q

Melanocytes

A

-have long branching processes
-produce and store the pigment melanin in response UV light exposure
-tanning is result of melanocytes producing melanin to block UV light from causing mutations in DNA in keratinocytes and fibroblasts

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18
Q

Tactile Cells

A

-few in number and scattered about
-sensitive to touch and when compressed they release chemicals that stimulate sensory nerve endings
-more common in sensitive areas like fingertips

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19
Q

How is skin classified as thick or thin?

A

number of layers and thickness of stratified squamous epithelium

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20
Q

Thick skin

A

-palms of hands and soles of feet
-has all 5 epidermal strata
-0.4mm-0.6mm thick
-houses sweat glands but no hair follicles or sebaceous glands

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21
Q

Thin skin

A

-covers most of body
-has 4/5 layers of epidermis (lacks stratum lucidum)
-contains hair follicles, sebaceous glands, and sweat glands
-0.075-0.150mm thick

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22
Q

Skin color

A

-normal skin color results from colors of hemoglobin, melanin, and carotene

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23
Q

Hemoglobin

A

-exhibits a bright red color upon binding oxygen, thus giving blood vessels in dermis a reddish tint that is most easily seen in light pigmented individuals

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24
Q

Melanin

A

-pigment produced and stored in melanocytes
-2 types: eumelanin (brown and black) and pheomelanin (light tan, yellow, and red)
-all people have same number of melanocytes
-melanocyte activity, type of melanin present, and color of melanin produced by
these cells result in different color skin tones

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25
Q

Carotene

A

-yellow-orange pigment that is acquired from various yellow-orange veggies (carrots, corn, and squashes)
-accumulates inside keratinocytes of stratum corneum and in subcutaneous fat
-several forms (alpha, beta, ect)
-beta is most common and is converted to vitamin A in liver

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26
Q

Albinism

A

-inherited recessive condition where enzyme needed to produce melanin is nonfunctional
-melanocytes are unable to produce melanin
-individuals have white hair, pale skin, and pink irises

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27
Q

Nevus

A

-commonly called a mole
-harmless, localized overgrowth of melanocytes
-may become malignant melanoma due to excessive UV light exposure

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28
Q

Freckles

A

-yellowish or brown spots that represent localized areas of increased melanocyte activity, not an increase in number

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29
Q

Hemangioma

A

-anomaly that results in skin discoloration due to blood vessels that proliferate to form a benign tumor

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30
Q

Capillary hemangiomas

A

-strawberry colored birthmarks
-appear in the skin as bright red to deep purple nodules that are usually present at birth and disappear in childhood
-development may occur in adults

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31
Q

Cavernous hemangiomas

A

-port wine stains
-involve larger dermal blood vessels and may last lifetime

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32
Q

Friction ridges

A

-ridge patterns follow contours of skin
-found on palms, fingers, soles, and toes
-help increase friction on contact, so hands can firmly grasp items and feet don’t slip when barefoot
-some suggest they also provide flexibility to skin and allow it to be deformed without damage
-when sweat glands and oil glands release secretions, noticeable fingerprints may be left on surfaces
-unique identifier because no 2 people have same fingerprint (not even identical twins)

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33
Q

Dermatoglyphics

A

study of friction ridge patterns

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34
Q

Dermis

A

-deep to epidermis and ranges in thickness from 0.5-3mm
-composed of connective tissue proper
-contains mostly collagen fibers, with some elastic and reticular fibers too
-contains dendritic cells, blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve ending, and smooth muscle associated with hair follicle (arrector pili)

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35
Q

Two regions of dermis

A

1) Superficial papillary layer
2) Deeper reticular layer

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36
Q

Papillary layer

A

-superficial part of dermis
-composed of areolar tissue
-derives name from projections called dermal papillae
-dermal papillae and epidermal ridges work together to increase area of contact between 2 layers and interlock them

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37
Q

Dermal papillae

A

-contains capillaries that supply nutrients to cells of epidermis
-contain sensory nerve endings that serve as tactile receptors (monitor touch on surface of epidermis)

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38
Q

Reticular layer

A

-forms deeper, major portion of dermis that extends from papillary layer to underlying subcutaneous layer
-consists primarily of dense irregular connective tissue
-collagen fibers are interwoven into meshwork that surrounds structures in dermis

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39
Q

Lines of cleavage

A

-identify predominant orientation of collagen fiber bundles
-surgical incisions should be made parallel to lines of cleavage to ensure incision remains closed, rapid healing, and prevention of scarring

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40
Q

Striae

A

-Stretch marks
-caused by tearing of collagen fibers when skin is stretched beyond capacity (exceeds elastic capacity)

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41
Q

Subcutaneous layer

A

-NOT considered part of integument
-deep to integument
-areolar and adipose tissue
-reticular layer of dermis is interwoven with it to stabilize skin position and bind it to underlying structures
-pads and protects body, acts as energy reservoir, and provides thermal insulation
-high vascularized (many drugs injected here)
-thickness and distribution influenced by sex hormones
-testosterone=fat accumulates at neck, upper arms, abdomen, lower back, and
butt
-estrogen=layer is thicker overall and accumulates in mammary regions, butt, hips,
and thighs

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42
Q

Functions of Integument

A

-Protection from external environment
-Prevention of water loss and gain
-Vitamin D synthesis
-Secretion
-Absorption
-Temperature regulation
-Assisting immune system
-Sensory perception

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43
Q

Protection from external environment

A

-protects against harmful chemicals, toxins, microbes, and excessive heat or cold
-protects deeper tissues from solar radiation, especially UV

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44
Q

Prevention of Water Loss or Gain

A

-epidermis is water resistant not waterproof
-some water is lost through sweat but more is lost through transpiration
-prevents major absorption of water (don’t swell up when taking a bath)

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45
Q

Transpiration

A

Process in which fluids slowly penetrate through epidermis and evaporate into surrounding air

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46
Q

Vitamin D Synthesis

A

-at exposure to UV light keratinocytes converted steroid molecule to vitamin D3 (cholecalciferol)
-vitamin D3 is them transported to liver/kidneys where it becomes calcitriol (active from of vitamin D)
-increased absorption of Ca and phosphate from small intestine, which results in more calcium being absorbed in foods we eat

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47
Q

Secretion

A

-Sweat releases excess heat from body
-also alters electrolyte level (excretes water, urea, and salts0
-Sebum lubricates epidermis and hair
-helps make skin water resistant

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48
Q

Absorption

A

-taking in of a gas, liquid, light, or heat
-skin can absorb certain chemicals and drugs such as estrogen from birth control patch or nicotine from nicotine patch
-skin is selectively permeable
-skin can absorb small, nonpolar molecules

49
Q

Transdermal administration

A

-drugs that are soluble in oil or lipid-soluble carriers may be administered by patch on skin
-drug slowly penetrates epidermis and can be absorbed into blood vessels of dermis
-allows for continual, slow absorption of drug over extended period of time

50
Q

Temperature regulation

A

-Dermal blood vessels can vasoconstrict (colder temps) and vasodilate (warmer temps)
-sweating from sweat glands also cools body

51
Q

Immune function

A

-epidermal dendritic cells and dendritic cells of dermis

52
Q

Sensory reception

A

-ability of tactile sensory receptors to detect stimuli such as touch or pressure
-seven major types of sensory receptors are housed within skin to detect, distinguish, and interpret stimuli from external environment

53
Q

Epidermal derivatives

A

Nails, hair, and exocrine glands

54
Q

Nails

A

-scalelike modifications of stratum corneum
-protect distal tips of digits during jumping, kicking, or catching
-fingernails also assist in grasping objects

55
Q

Parts of nail

A

-each nail has a free edge, nail body, nail root, nail plate, nail bed, nail matrix, lunula, nail folds, cuticle, and hyponychium

56
Q

Free edge

A

Part of finger nail that you would clip

57
Q

Nail body

A

-Actual nail
-Appears darker/pinkish because of bloodflow in underlying capillaries

58
Q

Nail root

A

Proximal part embedded in skin

59
Q

Nail plate

A

Composed of free edge, nail body, and nail root

60
Q

Nail bed

A

Contains the deeper, living cell layers of epidermis and is covered by the nail body

61
Q

Nail matrix

A

-Actively growing part of nail
-formed at nail root and proximal end of nail body, where nail bed thickens

62
Q

Lunula

A

Whitish, senilunar area of proximal end of nail body

63
Q

Nail folds

A

Folds of skin along the lateral and proximal borders of nail that overlap nail

64
Q

Eponychium

A

-Cuticle
-narrow band of epidermis extending from margin of nail wall onto nail body

65
Q

Hyponychium

A

Area of thickened epithelium underlying free edge of nail

66
Q

Brittle nails

A

-prone to vertical splitting and separation of nail plate layers at free edge
-overexposure to water or certain household chemicals can cause this

67
Q

Ingrown nail

A

-occurs when edge of nail digs into skin around it
-characterized by pain and inflammation
-may result from overly tight shoes and improper trimming of nails

68
Q

Nail pitting

A

-refers to tiny depressions or shallow holes in nail body
-usually a symptom of another disorder like psoriasis, alopecia areata, dermatitis, or connective tissue disorder

69
Q

Nail clubbing

A

-tip of finger enlarges and edges of nail grow and curve around tip
-occurs over period of years and is indicative of hypoxia (inadequate blood flow to tissue)
-often seen in conditions associated with hypoxia (smoking, cardiovascular disease, and diabetes)

70
Q

Onychomycosis

A

-fungal infection that occurs in nails constantly exposed to warmth and moisture
-fungus starts to grow under nail and eventually causes yellow discoloration, a thickened nail, and brittle, cracked edges

71
Q

Spoon nail (Koilonychia)

A

-outer surface if nails are concave instead of convex
-usually sign of iron deficiency and treating deficiency should alleviate condition

72
Q

Beau’s lines

A

-run horizontally across nail and indicate temporary interference with nail growth at time portion of nail was formed
-caused by injury to nail, severe illness, or chronic malnutrition

73
Q

Vertical ridging

A

-common and usually doesn’t indicate any serious medical problem
-occurs more frequently as we age

74
Q

Hair

A

-found almost everywhere on body except palms of hands, palmar surface of fingers, sides and soles of feet/toes, lips, and portions of external genitalia

75
Q

Pilus

A

-a single hair
-composed of keratinized cells growing from hair follicles that extend into dermis and often subcutaneous layer too
-differences in density due to texture and pigmentation

76
Q

3 Kinds of Hair

A

1) Lanugo
2) Vellus
3) Terminal

77
Q

Lanugo

A

-fine, unpigmented, downy hair that first appears on fetus in last trimester
-at birth, most has been replaced vellus

78
Q

Vellus

A

-fine, unpigmented/light pigmented
-primary human hair
-found on upper and lower limbs

79
Q

Terminal hair

A

-Coarser, pigmented, and longer than vellus
-grows on scalp, eyebrows, and eyelashes
-at puberty, replaces vellus hair in axillary and pubic regions
-under influence of testosterone, forms beard

80
Q

Three zones of hair

A

1) Hair bulb
2) Root
3) Shaft

81
Q

Hair bulb

A

-consists of epithelial cells and is a swelling at the base where hair originates in dermis
-epithelium at base of bulb surrounds a small hair papilla (composed of small amount of connective tissue containing tiny blood vessels and nerves)

82
Q

Root

A

Zone of hair extending from bulb to skin surface

83
Q

Shaft

A

-portion that extends beyond skin surface
-contains living epithelial cells whereas root and shaft consist of dead epithelial cells

84
Q

Hair matrix

A

-structure immediately adjacent to hair papilla in hair bulb
-epithelial cells near center divide, producing new cells that are gradually pushed toward surface
-specialized type of keratinization occurs here

85
Q

Medulla

A

-remnant of soft core of matrix
-composed of loosely arranged cells and air spaces
-contains soft, flexible keratin
-not found in all hair types

86
Q

Cortex

A

Several layers of flattened cells closer to outer surface of developing hair form relatively hard cortex

87
Q

Cuticle

A

A single cell layer around the cortex that coats the hair

88
Q

Hair follicle

A

-oblique tube that surrounds hair root
-extends into dermis/subcutaneous layer
-2 concentric layer:
1) outer connective tissue root sheath (originates from dermis)
2) inner epithelial tissue root sheath (originates from epidermis)
-arrector pili extend from hair follicle to dermal papillae

89
Q

Arrector pili

A

-thin ribbons of smooth muscle
-stimulation is usually result of an emotional state (like fear or rage) or response to cold temperatures
-upon stimulation by nervous system, arrector pili contract, pulling on hair follicle and elevating hair creating goosebumps

90
Q

Functions of Hair

A

1) Protection
-protects scalp from sunburn and injury
-hair within nostrils entrap particles and prevent entry deeper into respiratory
system
-hair in external ear canal protect ear from insects and foreign particles
-eyelashes protect eye
2) Heat retention = prevents loss of conducted heat from scalp to surrounding air
3) Sensory reception = follicles have associated tactile receptors that detect light touch
4) Visual identification = important in determining age and identifying individuals

91
Q

Hair color

A

-determined by melanin synthesized in matrix adjacent to hair papillae
-variations in hair color = genetic differences in structure of melanin
-also influenced by environmental and hormonal factors
-grey hair=reduction in melanin production in hair follicle
-white hair= complete stoppage of melanin production

92
Q

3 Stages of Hair Growth Cycle

A

1) Anagen
2) Catagen
3) Telogen

93
Q

Anagen Phase

A

-Active phase of hair growth where living cells in hair bulb are rapidly growing, dividing, and transforming into hair
-longest part of cycle and lasts 18 months-7 years depending on location on body and individual’s genetics
-each hair strand grows 0.5-1cm/month
-on scalp, 80-95% of follicles are in this stage

94
Q

Catagen phase

A

-Brief regression period where cell division ceases and follicles undergo involution
-Lasts about 3-4 weeks

95
Q

Telogen phase

A

-Resting phase and usually when hair is shed
-after 3-4 months in phase, cells of hair bulb start regrowing and follicle reenters anagen phase

96
Q

Alopecia areata

A

-“spot baldness”
-circular bald patches develop on scalp/body
-autoimmune disorder where body mistakes selected hair follicles as foreign and attacks them

97
Q

Diffuse hair loss

A

Hair is shed from all parts of scalp

98
Q

Male pattern baldness

A

-causes hair loss first from only crown region of scalp rather than uniformly
-Baldness allele is dominant in genetic males and is expressed only in presence of testosterone
-in genetic females, baldness allele is recessive

99
Q

Hirsutism

A

-excessive hairiness in body areas that normally do not have terminal hair (face, chest, and back)
-affects all individuals regardless of sex
-most commonly caused by excess of male sex hormones either through medical condition (like PCOS) or certain medications (like anabolic steroids)

100
Q

Exocrine glands in skin

A

1) Sweat glands
2) Sebaceous glands

101
Q

Sweat glands

A

-2 types: merocrine(eccrine) and apocrine
-have coiled tubular secretory portion that is located in reticular layer of dermis and a sweat gland duct that transports secretions to surface of epidermis or into hair follicle
-contain myoepithelial cells (specialized epithelial cells with contractile proteins like muscle)
-in response to nervous system, contract to squeeze gland, causing it to discharge
its accumulated secretions

102
Q

Sweat pore

A

indented region where sweat gland duct opens on epidermal surface

103
Q

Merocrine (Eccrine) Sweat Glands

A

-most numerous and widely distributed sweat glands
-3-4 million on integument
-simple coiled tubular glands that discharge secretions (sweat) directly into surface of skin
-major function is thermoregulation
-provide means for loss of both water and electrolytes, as well as some protection from environmental hazards by diluting harmful chemicals and preventing growth of microorganisms

104
Q

Sweat

A

-clear secretion released by exocytosis
-99% water
-1% other chemicals including electrolytes (Na and Cl), metabolites (ex. lactate), and waste products (urea and ammonia)

105
Q

Apocrine Sweat Glands

A

-coiled, tubular glands that release secretions into hair follicles in axillae, around nipples, in pubic region, and in anal region
-has larger lumen than merocrine gland and secretions are different
-secretions are viscous and cloudy, containing proteins and lipids that are acted upon by bacteria to produce a distinct odor
-glands become active around puberty

106
Q

Sebaceous Glands

A

-holocrine glands that produce an oily, waxy secretion called sebum that is usually discharged into a hair follicle and onto hair itself
-sebum acts as lubricant to keep skin and hair from becoming dry, brittle, and cracked
-sebum also has some bactericidal properties
-secretions of sebum is stimulated by hormones, especially male sex hormones
-sebaceous glands relatively inactive in childhood and are activated during
puberty

107
Q

Acne

A

-Plugged ducts of sebaceous glands
-Types of acne lesions:
-comedo
-papule/pustule
-nodule
-cyst

108
Q

Comedo

A

-Sebaceous gland plugged with sebum
-Open comedo = blackhead, plugged material is dark, blackish color
-Closed comedo = whitehead, top surface is whitish color

109
Q

Papule and Pustule

A

-both are domed shaped lesions
-papules are fluid filled, form red elevations on skin, and do not contain pus
-papules may become pustules which are filled with a mixture of white blood cells, dead skin cells, and bacteria (called pus)

110
Q

Nodule

A

Similar to pustule but extends into deeper into skin layers, usually rupturing hair follicle wall; prone to scarring

111
Q

Cyst

A

Large fluid filled nodule that can become severely inflamed and painful and can lead o scarring

112
Q

Ceruminous glands

A

-modified apocrine sweat glands only located in external acoustuc meatus (ear canal)
-secretions from a waterproof earwax called cerumen
-cerumen and tiny hairs in meatus help trap foreign particles or small insects and keeps them from reaching eardrum
-cerumen also helps lubricate external acoustic meatus and eardrum

113
Q

Mammary glands

A

-modified apocrine sweat glands
-present in both males and females but glands only functional in pregnant and lactating females when they produce breast milk (a secretion that nourishes offspring)
-development of glands and its secretions are controlled by complex interaction between gonadal and pituitary hormones

114
Q

How do damaged tissues repair themselves?

A

Regeneration or fibrosis

115
Q

Regeneration

A

-Replacement of damaged or dead cells with same cell type by cell division
-restores tissue function
-when regeneration is not possible because part of the organ is too severely damaged or cells lack capacity to divide, body fills gap with scar (fibrous) tissue

116
Q

Fibrosis

A

-process of scar tissue deposition in connective tissue during healing
-binds damaged parts together
-replacement scar tissue is composed mostly of collagen fiber and produced by fibroblasts of connective tissue
-some structural restoration occurs but functional activities not restored

117
Q

Psoriasis

A

-chronic autoimmune disorder that has periods of flare-ups and remissions throughout a person’s lifetime
-T-lymphocyte mistakenly attacks keratinocytes, causing rapid overgrowth and overproduction of new skin cells
-normal sloughing off cycle is thrown out of balance and proliferation of cells develops into patches of whitish, scaly skin (called plaques) on epidermal surface

118
Q

Steps of Wound Healing

A

1) Cut blood vessels release blood into wound; blood brings in clotting proteins, numerous leukocytes, and antibodies
2) Blood clot forms; macrophages and neutrophils clean wound of cellular debris
3) Cut blood vessels regenerate and grow; soft mass deep in wound becomes granulation tissue; macrophages within wound begin to move clotted blood; fibroblasts produce new collagen fibers
4) Epithelial regeneration; new epithelial cells migrate over wound, moving internally to now superficial remains of clot/scab; connective tissue is replaced by fibrosis

A&P (13 decks)

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