1. Chapter 5 Integumentary System
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 5 Integumentary System
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. Membranes Review membranes Cutaneous Mucous Serous
Parietal vs visceral
Pleura, pericardium, peritoneum

3. Integumentary System Skin (cutaneous membrane)
Main layers – superficial to deep
Epidermis
Dermis
Hypodermis – not always considered part of skin
Slide 4.8
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4. Skin Structure page 101 Slide 4.13b Figure 4.4
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5. Epidermis Epidermis – outer layer
Keratinized stratified squamous epithelium
Avascular (hardened by keratin)
Renews itself ~ every 45 days
Slide 4.10a
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6. Epidermis – cell types Keratinocytes
produce keratin – waterproofing protein
Why important?
Originate in deeper layers & get pushed to surface – becomes keratin filled & dies
Connected to each other by desmosomes & tight junctions
Cell production & keratinization are accelerated in areas of friction
Callus – thickened skin
Slide 4.10a
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7. Epidermis – cell types Melanocytes
Produce melanin which accumulates on superficial side of nucleus
Why? to prevent DNA mutation from the UV radiation
Slide 4.10a
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8. 5 strata of the Epidermis
From deep to superficial
Stratum basale – highly mitotic
Approx. 25% melanocytes
Stratum spinosum
Slightly mitotic
Contains Langerhan’s macrophages
synthesizes tonofilaments – beginning of keratinization
Slide 4.10a
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9. 5 strata of the Epidermis
Stratum granulosum
Also contains Langerhans cell
contains keratohyalin granules
Stratum lucidum
found in thicker epidermis – palms, soles, callus
Completely keratinized (and dead!)
Keratohyalin granules + tonofilaments = keratin fibrils
Slide 4.10a
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10. 5 strata of the Epidermis
Stratum corneum
Also completely keratinized (& dead)
Tough, waterproofing protection
AGAIN: Why is waterproofing important?
Slide 4.10a
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12. Dermis Strong, flexible CT - Two layers Papillary layer
Contains areolar CT
Dermal papillae – indent into the epidermis – form fingerprints
What else is important about these?
Also contain nerve receptors, capillary loops etc.
Slide 4.13a
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13. Blister Dermal – epidermal junction Held together by desmosomes
Blister - separation due to mechanical stress
What 2 sublayers actually separate?

14. Dermis Reticular layer
Dense irregular CT – also contains Blood vessels, Nerve receptors, Glands
cleavage lines – separation between collagen bundles
flexure lines – dermis secured to hypodermis
stretch marks – dermal tears
Slide 4.13a
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17. Hypodermis Deep to dermis is the hypodermis
Not usually considered part of the skin – superficial fascia
Anchors skin to underlying organs
Composed mostly of adipose tissue
Very vascular
Site of subcutaneous injections
Slide 4.10b
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19. Skin color

20. Normal Skin Color Determinants
Determined by a combo of:
Types of pigments present
Blood circulation
Stratum corneum thickness
Slide 4.14
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21. Normal Skin Color Determinants
Melanin
Yellow, brown or black pigments produced in melanocytes found in stratum basale – transferred to keratinocytes
Local accumulations form freckles & pigmented moles
Amount of melanin produced depends upon genetic and exposure to sunlight
Solar elastosis – clumping of elastin fibers = leathery looking skin
Slide 4.14
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22. Normal Skin Color Determinants
Carotene
Orange-yellow pigment from some vegetables
Vitamin A precurser – vitamin A forms retinal which is needed for sight
Accumulates in adipose and stratum corneum cells
Slide 4.14
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23. Normal Skin Color Determinants
Hemoglobin
Red coloring from oxygenated blood cells in dermis capillaries
Oxygen content determines the extent of red coloring
More obvious in fair skinned individuals
Vasodilation causes increase in flow
Vasoconstriction causes decrease in flow
Slide 4.14
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24. Skin as a Diagnostic
Skin color is influenced by emotional & disease states: You should know the states that cause these.
Cyanosis – bluish color - lack of oxygen
Erythema – redness – heat, inflammation, fever
Pallor – paleness – lack of blood flow
Jaundice – yellowish color – liver damage
Bronzing – bronze (tan) – Addison’s disease
Hematomas – black & blue – blood under skin
Slide 4.14
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25. End of Quiz #1 Material

26. Skin Derivatives

27. Appendages of the Skin Hair Shaft – projects from skin
Determines hair curliness
Flat = curly
Oval = wavy
Round = straight
Root – embedded in skin
Figure 4.7c
Slide 4.18
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28. Hair Anatomy Central medulla Cortex surrounds medulla
Cuticle on outside of cortex
Single layer of overlapping cells
Highly keratinized
Split ends
Figure 4.7b
Slide 4.19
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30. Hair

31. Hair Color Caused by proportions of 3 types of melanin
Determined by genetics
Melanin is replaced by air bubbles in gray/white hair – causes different texture
Figure 4.7b
Slide 4.19
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32. Hair Follicle Hair Extends into dermis & hypodermis
Produced by hair bulb- expanded end
Papilla contains blood vessels for nourishment
Matrix = growth zone
Figure 4.7c
Slide 4.18

33. Associated Hair Structures
Define Hair follicle
Dermal and epidermal sheath surround hair root
Arrector pilli
Smooth muscle regulated by emotions
Contraction pulls hair upright
Normally at angle
Figure 4.7a
Slide 4.20
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34. Hair Types Vellus hair – softer body hair
Terminal hair – coarser hair found in axillary & anogenital regions
Lanugo – newborn baby fuzz
Figure 4.7a
Slide 4.20
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35. Hair Growth Influenced by (in order): nutrition hormones Blood flow
Growth cycles – see notes:
Growth phase
Resting phase
Figure 4.7a
Slide 4.20
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36. Thought Question
Why is the hair on your head longer than the hair in your eyebrows?
Why does some hair fall out every day?
Approx 100 hairs per day are lost from your head! That is why your sink is stopped up

37. Alopecia - Baldness Male pattern baldness Sex linked, recessive trait
Punnett Square!
Terminal hair replaced by vellus hair
Progresses posteriorly
Cure: drugs that inhibit testosterone production
Side effects?
Figure 4.7a
Slide 4.20
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38. Minoxidil – “Rogaine” Background: Reduces high blood pressure
Current use: stimulates hair regrowth in some men
Popularity: does not cause loss of sex drive or impotence
Figure 4.7a
Slide 4.20
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39. Imbalance Thinning hair can be caused by an abundance of factors.
Heterozygous traits
Nutrition
Medications
Stress (affects nutrition & hormones)
Hormones
Physical factors

40. Appendages of the Skin Nails Scale-like modifications of the epidermis
Heavily keratinized
Stratum basale extends beneath the nail bed to form nail matrix
Responsible for growth ( matrix region)
Lack of pigment makes them colorless
Slide 4.21
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41. Nail Structures Know all parts labeled on diagram Slide 4.22
Figure 4.9
Slide 4.22
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42. Sweat Glands Sudoriferous (sweat) glands Three types Eccrine glands
Widely distributed in skin: abundant on palms, soles, forehead
Open via duct to pore on skin surface
Sweat composition: mostly water with a slightly acidic 4-6 pH
Function: thermoregulation
Slide 4.16
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43. Sweat Glands Apocrine glands (also sudoriferous)
Ducts empty into hair follicles
Found mainly in anogenital & axillary region
Begin to function at puberty due to hormones
Organic contents: Fatty acids and proteins – can have a yellowish color that stains clothes
Odor is from associated bacteria
Slide 4.17
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44. Sweat Glands Ceruminous glands Modified apocrine gland
Found in outer 1/3 of ear canal
Produce ear wax to trap “invaders”
Slide 4.17
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45. Appendages of the Skin
Sebaceous glands (all over except palms and soles of feet)
Produce oil for waterproofing
Lubricant for skin & kills bacteria
Most with ducts that empty into hair follicles
Glands are activated at puberty: stimulated by hormones
Acne – active infection of sebaceous glands: know imbalance terms page 103
Slide 4.15
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46. Integumentary Functions

47. Protection - biological
Biological – cells – macrophages & Langerhan’s cells engulf invaders.

48. Protection - mechanical
Mechanical – physical
Continuity – skin is made impermeable through the tight junctions & desmosomes
Keratin – physically blocks the passage of water and water soluble substances
Molecules that can pass through are:
Lipid soluble – O2, CO2, ADEK, steroids
Oleoresins – poison ivy & poison oak, etc – you have less than 10 min to wash it off!
Organic solvents – acetone, dry cleaning fluid, paint thinner
Heavy metals – Hg, Pb

49. Protection - Chemical Chemical
Skin secretions: tears, sweat, oil lower pH and contain lysozyme (chemical that lyses cells)
Melanin – pigment shield against UV radiation

50. Excretion
Limited amounts of nitrogen containing wastes (most is excreted in urine unless you have a kidney disorder
Sodium chloride
Diagnostic sign of cystic fibrosis

51. Homeostasis of Body Temperature
Heat production – chief determinant is muscle activity
Heat loss/gain
80% of heat transfer is through the skin – the rest is through the mucosa (dogs are opposite!)
Regulated by vasoconstriction & vasodilation since heat is carried primarily in the water content of the blood

53. Vitamin D Production
Vitamin D is important in the uptake of Calcium from the food you eat.
Ca has to be absorbed from your stomach into the blood to go anywhere
Cholesterol molecules when exposed to UV light become a Vitamin D precurser
Precurser becomes active in the liver & kidneys

54. Sensation Free nerve ending = pain
Meissner’s corpuscles = discriminating touch, light pressure (think fly on your arm)
Krause’s – cold
Ruffini’s – heat
Merkel Disc – Medium pressure
Pacinian corpuscle – Deep pressure (add this one to your notes)

56. End of Quiz 2 Material
Now Study!

57. Burns

58. Burns
Protein denaturation and cell death caused by heat, electricity, UV radiation, or chemicals
2 main dangers
Dehydration–Loss of fluids & Electrolytes lead to:
Renal Shutdown
Circulatory shock
Infection
Skin (mechanical)barrier lost
Immune system depresses
Slide 4.25
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59. Rules of Nines Way to determine the extent of burns
Primary importance is to estimate fluids needed for rehydration
Body is divided into 11 areas for quick estimation
Each area represents about 9%
You need to memorize these – page 108
Slide 4.26
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60. Rule of nines diagram

62. Partial Thickness Burns
First-degree burns
Only epidermis is damaged
Local redness, swelling, & pain
Usually heal in 2-3 days (short time period) with NO scarring
Slide 4.27
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63. Partial Thickness Burns
Second degree burns
Epidermis and upper dermis & structures within dermis are damaged
Appearance of blisters of any size
Skin regeneration in 3-4 weeks with some scarring
There is a danger of infection
Slide 4.27
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67. Full Thickness Burns Third-degree burns
Epidermis, Dermis and all structures within are completely destroyed
Usually painless at site of burn due to destruction of sense recept
Burn is gray-white, tan, brown, black, or deep cherry red
Surrounded by areas of 1st & 2nd degree burns that will be painful
Treatments are numerous but will involve skin grafting of some sort, fluid replacement and debridement
Slide 4.27
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70. All degrees of burns

71. Skin Cancer Skin cancer is the most common type of cancer
2 out of 5 cancers are skin cancers

72. Skin Cancer Cancer – uncontrolled cell growth
Caused by damage to the DNA usually through chemicals or radiation
Two types
Benign
Does not spread (encapsulated)
Malignant
Metastasized (moves) to other parts of the body
Slide 4.29

73. Skin Cancer Types Basal cell carcinoma
Least malignant - Most common type
Arises from stratum basale
cannot produce keratin
Boundary lost between dermis and epidermis
90% of skin cancers are basal cell
Seldom metastasizes – treated surgically or by radiation – 99% cure rate if caught early
Slide 4.30

74. Basal Cell Carcinoma

75. Basal Cell Carcinoma

76. Skin Cancer Types Squamous cell carcinoma
2nd most common skin cancer – most common in darker skinned people
Arises from stratum spinosum
Metastasizes to lymph nodes if left untreated
deaths in US per year
Early removal allows a good chance of cure
Slide 4.30
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77. Squamous Cell Carcinoma

78. Cumulative Effects IMPORTANT TO KNOW
Basal cell & squamous cell carcinomas are due to cumulative effects of the sun’s radiation (or chemical exposures as well)
These tend to develop in ages 30-40s after years of daily sun exposure

79. Skin Cancer Types Malignant melanoma
Least common BUT most deadly of skin cancers
Originates melanocytes
Metastasizes rapidly to lymph and blood vessels
Early detection is critical – see notes for survival rates
Slide 4.31
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80. Intensive Effects
Malignant Melanoma tends to occur in younger ages (as well as older people)
It is due to brief intense exposures (aka: sunburns)
This is the most serious form of skin cancer and MUST be caught early to be treated successfully!

81. ABCD Rule A = Asymmetry Two sides of pigmented mole do not match
B = Border irregularity
Borders of mole are not smooth
C = Color
Different colors in pigmented area
D = Diameter
Spot is larger then 6 mm in diameter (pencil eraser)
Mole starts growing/changing in size
Slide 4.32
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82. Malignant Melanoma

83. Melanomas

84. Melanomas

85. Prevention Ultraviolet Radiation is the main cause of all skin cancers
See notes for rest of information

86. Other Integumentary System disorders

87. Athlete’s Foot

88. Boils
Cold Sores

89. Skin Homeostatic Imbalances
Infections and allergies
Contact dermatitis
Exposures cause allergic reaction
Impetigo
Caused by bacterial infection
Psoriasis
Cause is unknown
Triggered by trauma, infection, stress
Slide 4.24
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90. Impetigo
Psoriasis