1. Chapter 6 Integumentary System
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2. Introduction
Two or more kinds of tissues grouped together and performing specialized functions constitutes an organ.
The skin and its various structures make up the integumentary system.
The skin is the largest organ in the body.

3. Skin and Its Tissues Many functions:
1) Protective covering – prevents many harmful substances from entering
2) Retards water loss
3) Regulates body temperature
4) Sensory organ (sense of touch)
5) Contains immune system cells
6) Synthesizes chemicals (ex: Vitamin D)
7) Excretes small amounts of waste

4. © The McGraw-Hill Companies, Inc./Al Telser, photographer
Layers of Skin
The skin is composed of two layers:
1) Epidermis
2) Dermis
Subcutaneous layer (hypodermis) -
Beneath dermis
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Stratified
squamous
epithelium
Dense irregular
connective
tissue
Adipose tissue
© The McGraw-Hill Companies, Inc./Al Telser, photographer

5. Epidermis Made of stratified squamous epithelium Lacks blood vessels
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Made of stratified squamous epithelium
(a)
Hair shaft
Epidermis
Hair follicle
(b)
Sebaceous gland
Dermis
Sweat
Sweat gland pore
Capillary
Stratum corneum
Stratum basale
Dermal papilla
Arrector pili muscle
Lamellated (Pacinian) corpuscle
Basement membrane
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
Sweat gland duct
Subcutaneous
layer T
Tactile (Meissner’s) corpuscle
Lacks blood vessels
Keratinized
Melanocytes produce melanin
(Melanosomes – pg. 174)
Rests on basement membrane
Thickest on palms and soles ( mm)
Other areas – thin: ( mm thick)
b: © Victor Eroschenko

7. b: © The McGraw-Hill Companies, Inc./Al Telser, photographer
Epidermis
There are five (5) layers of the epidermis:
Stratum corneum – outermost layer “horn-like”
Stratum lucidum (only in thick skin – palms, soles)
Stratum granulosum
Stratum spinosum
Stratum basale – deepest layer; melanocytes here
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Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Basement
membrane
Dermal papilla
Dermis
(a)
(b)
b: © The McGraw-Hill Companies, Inc./Al Telser, photographer

8. Come, Let’s Get Sun Burned

9. Epidermis Heredity and environment determine skin color
1) Genetic Factors:
All people have about the same number of melanocytes. Differences in color are due to differences in the amount of melanin produced, which is controlled by genes.
Albinism – genetic disease that affects many species. Melanin is not produced, so the skin and hair are very pale, and the eyes appear pale blue to red.
2) Environmental Factors also influence the amount of melanin:
UV rays from the sun (and sunlamps) and X-rays
stimulate melanocytes to produce more melanin and also
cause darkening of the melanin

10. Figure 06.03b
Pigment recipient cells
(pg. 174)

11. Epidermis Physiological Factors that also affect skin color:
Cyanosis – bluish tint to skin due to low blood oxygen concentration
Jaundice – yellowish skin tone due to liver disease (“bili lights” – pg. 177)
Blushing - Dilation of dermal blood vessels
Paleness - Constriction of dermal blood vessels due to low body temperature or being frightened, or anemia (low red blood cell count)
Carotene, a yellow-orange pigment in certain vegetables, can give skin a yellowish color if a person consumes too much

12. Dermis made of Dense irregular connective tissue
Dermal papillae – nipple-like conical
projections of dermis into the
epidermis. Increase surface area
for epidermal cells to receive
nutrients and oxygen by diffusion
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Hair shaft
Sweat gland pore
Sweat
Stratum corneum
Epidermis
Stratum basale
Capillary
Dermal papilla
Basement membrane T
actile (Meissner’s) corpuscle
Dermis
Contains:
Muscle cells, (arrector pili muscle),
Hair follicles, blood vessels,
Sebaceous glands, sweat glands,
Sensory and motor nerve endings
Sebaceous gland
Arrector pili muscle
Sweat gland duct
Lamellated (Pacinian) corpuscle
Hair follicle
Subcutaneous
layer
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
(a)
On average mm thick

13. Dermis
Fingerprints are undulations (ridges) in the skin. The pattern is genetically determined, but is also influenced by early fetal movements in the womb. This is why even indentical twins have unique fingerprints.

14. Subcutaneous Layer Also known as the hypodermis
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Loose connective tissue and Adipose tissue
Hair shaft
Sweat gland pore
Sweat
Stratum corneum
Epidermis
Stratum basale
Capillary
Dermal papilla
Basement membrane T
actile (Meissner’s) corpuscle
Dermis
Insulates, cushions
Sebaceous gland
Arrector pili muscle
Sweat gland duct
Lamellated (Pacinian) corpuscle
Hair follicle
Many blood vessels present
Subcutaneous
layer
Sweat gland
Nerve cell process
Adipose tissue
Blood vessels
Muscle layer
(a)

15. 6.3: Accessory Structures of the Skin
Accessory structures of the skin originate from the epidermis and include:
Hair follicles
Nails
Skin glands

16. Hair Follicles Arrector pili muscle – Follicle is made from
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Follicle is made from
epidermal cells
that form a tube-like
depression into the dermis.
How a hair is formed:
specialized epidermal cells
at base of hair follicle divide
and push older cells upward.
These become keratinized
and die, forming the hair
shaft. (hair papilla – pg. 178)
Hair shaft
Pore
Sebaceous
gland
Arrector pili
muscle
Hair root
(keratinized
cells)
Hair follicle
Eccrine
sweat gland
Region of
cell division
Arrector pili muscle –
contracts and forms
“goose bumps”
Hair papilla
Dermal blood vessels
(a)

18. Nails Protective covering of digits Three parts:
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Protective covering of digits
Three parts:
1) Nail plate = the nail
2) Nail bed – underlying
tissue to which the nail
is attached
3) Lunula - whitish half-
moon shaped region at
base of nail. Specialized
epidermal cells give rise
to keratinized cells that
form the nail plate, pushing it forward over the nail bed.
Lunula
Nail bed
Nail plate

19. Sebaceous Glands Holocrine glands
Usually associated with hair follicles
Secrete sebum (oil) – softens
and waterproofs hair and skin
Acne – disorder of sebaceous
glands. Whiteheads and black-
heads caused by excess sebum
and squamous epithelial cells
clogging the gland.
© Per H. Kjeldsen

20. Sweat Glands Two types of glands that produce sweat:
Eccrine – respond throughout
life to increased body temperature. Ducts open at the surface of skin as a pore.
Apocrine – become active at
puberty. Responsible for
causing body odor (when
bacteria metabolize the
secretion). Also produce moist-
ure when a person is upset,
frightened or in pain, and during
sexual arousal. Ducts open into
hair follicles.
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Hair shaft
Pore
Dermal
papilla
Sebaceous
gland
Duct
Hair
follicle
Eccrine
sweat
gland
Apocrine
sweat
gland

21. Sweat Glands
Sweat is mostly water, but also contains small amounts of salts and wastes, such as urea and uric acid. Thus, sweating is also an excretory function.
Other glands classified as specialized sweat glands (do not produce sweat):
Ceruminous glands – located in external ear canal. Produce cerumen = ear wax.
Mammary glands – in the breast. Produce milk.

22. Regulation of Body Temperature
Regulation of body temperature is vitally important because even slight shifts can disrupt the rates metabolic reactions.
*Study this diagram in your text and know it.

23. Heat Production and Loss
Heat is a product of cellular metabolism
The most active body cells are the heat producers and include:
Skeletal muscle
Cardiac muscle
Cells of certain glands such as the liver
The primary means of heat loss is radiation
Also there is conduction, convection and evaporation
(definition of these terms – pg. 182 new text)
Hyperthermia – abnormally high body temperature
Hypothermia – abnormally low body temperature

24. Healing of Wounds and Burns
Inflammation is a normal response to injury or stress.
Blood vessels in affected tissues dilate and become more permeable, allowing fluids to leak into the damaged tissues. (This can aid healing by providing more nutrients and oxygen.)
Inflamed skin will become:
Reddened
Swollen
Warm
Painful

26. Healing of a Cut Healing of a Cut
If injury extends into the dermis (or subcutaneous) layer:
Blood vessels break – Blood clot forms 
fluids seep into area and dries - Scab forms 
epithelial cells grow beneath scab - bridging gap 
fibroblasts migrate to area - secrete collagen fibers that bind edges of wound; C.T. matrix releases growth factors that stimulate cells to divide and replace tissue 
blood vessels invade; phagocytic cells remove dead tissue  scab sloughs off
Granulation - small, rounded mass consisting of a
new blood vessel + fibroblasts secreting collagen. These
Form in large, open wounds that eventually produce a scar composed primarily of collagen.

27. Steps of Wound Healing (pg. 185)
Scab

28. Burns & Healing
First degree burn – Epidermis only (superficial, partial-thickness).
Heals within days-2 weeks, with no scarring.
Second degree burn – Epidermis and partial dermis (deep,
partial-thickness). Blisters appear. Healing – stem cells associated
with accessory structures deep in the dermis (glands, hair follicles) –
New epidermis is formed. Can completely heal with no scarring.
Third degree burn – Epidermis, full dermis, and accessory structures (deep, full-thickness). Dry & leathery. Healing – Growth of epithlium inward from margin of burn. Loss of function.
May require a skin transplant:
Allograft – person to person (cadaveric skin)
Autograft (Homograft) – patient’s own tissue
Various skin substitutes

29. “Rule of Nines”
Formula used by physicians to estimate the extent of body surface area affected in a burn patient.
Skin’s surface area is divided into regions that equal 9% (or some multiple of 9%) of total surface area.
Estimate is important for planning:
Body fluid and electrolyte replacement
Covering the area with skin or skin substitutes

30. “Rule of Nines” for Adults
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Anterior head
and neck 41/2%
41/2%
Anterior and posterior head and neck 9%
41/2%
Posterior head
and neck 41/2%
Anterior
trunk
18%
Anterior and
posterior upper
extremities
18%
Posterior
trunk
18%
Anterior upper
extremities 9%
Anterior and
posterior trunk
36%
Posterior upper
extremities 9%
41/2%
41/2%
41/2%
41/2%
Perineum 1% 9% 9% 9% 9%
Anterior lower
extremities 18%
Anterior and
posterior lower
extremities
36%
Posterior lower
extremities 18%
100%

31. 6.6: Lifespan Changes Skin becomes scaly Age spots appear
Epidermis thins
Dermis becomes reduced
Loss of fat (chill easier)
Wrinkling
Sagging
Sebaceous glands secrete less oil
Melanin production slows
Hair thins
Number of hair follicles decreases
Nail growth becomes impaired
Sensory receptors decline
Body temperature unable to be controlled as well
Diminished ability to activate Vitamin D

32. Important Points in Chapter 6: Outcomes to be Assessed
6.1: Introduction
Define organ, and name the large organ of the integumentary system.
6.2: Skin and Its Tissues
List the general functions of the skin.
Describe the structure of the layers of skin.
Summarize the factors that determine skin color.
6.3: Accessory Structures of the Skin
Describe the accessory structures associated with the skin.
Explain the functions of each accessory structure of the skin.

33. Important Points in Chapter 6: Outcomes to be Assessed
6.4: Regulation of Body Temperature
Explain how the skin helps regulate body temperature.
6.5: Healing of Wounds and Burns
Describe the events that are part of wound healing.
Distinguish among the types of burns, including a description of healing with each type.
6.6: Lifespan Changes
Summarize lifespan changes in the integumentary system.

34. Read 1) Transdermal patches – pg. 113 (old text)
2) Decubital ulcers (bed sores) – pg. 116
3) Skin cancer – pg. 119

36. Burn Treatment
A 32 year old man was attempting to get rid of some weeds in an overgrown garden by dousing them with gasoline and burning them. The can of gasoline ignited and exploded, and he sustained 3rd degree burns on both arms, his chest, back and head. Calculate the following (Body wt = 180 lbs.):
1) Percent body surface area burned (TBSA), using the “Rule of Nines.”
2) Fluid replacement therapy for the first 24 hours, using the Parkland formula:
Lactated Ringers 4 mls x kg. body wt. x %TBSA (Round weight to the nearest whole kg)
Half of the amount infused within the first 8 hours post-injury
The remainder infused over the next 16 hours

37. “Rule of Nines” for Adults
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Anterior head
and neck 41/2%
41/2%
Anterior and posterior head and neck 9%
41/2%
Posterior head
and neck 41/2%
Anterior
trunk
18%
Anterior and
posterior upper
extremities
18%
Posterior
trunk
18%
Anterior upper
extremities 9%
Anterior and
posterior trunk
36%
Posterior upper
extremities 9%
41/2%
41/2%
41/2%
41/2%
Perineum 1% 9% 9% 9% 9%
Anterior lower
extremities 18%
Anterior and
posterior lower
extremities
36%
Posterior lower
extremities 18%
100%

38. Calculations Calculate the TBSA using Rule of Nines:
Arms (9% each = 18%) + Chest (18%) + Back (18%) + Head (9%) = 63%
2) Convert weight from pounds to kilograms:
180 lbs. x 1 kg/2.2 lbs. = 81.8 kg – round to 82 kg
3) Calculate fluids for the first 24 hours using the Parkland formula:
4 ml/kg x 82 kg. x 63 = 20,664 ml in first 24 hours.
Give half within the first 8 hours post-injury; Give other half the remaining 16 hours
If the injury occurred at 6:00 pm, 10,332 ml should be administered by 2:00 am. Then 10,332 ml should be administered 2:00 am - 6:00 pm.