Would you be enticed by an
advertisement for a coat that is
waterproof, stretchable, washable,
and permanent press, that is
guaranteed to last a lifetime with
reasonable care?
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-2
The Integumentary System
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-3
Learning Outcomes
List the functions of skin.
Explain the role of skin in regulating body
temperature.
Describe the layers of skin and the characteristics
of each layer.
Explain the factors that affect skin color.
Identify and describe common skin lesions.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-4
Learning Outcomes (cont.)
List the accessory organs of skin and describe
their structures and functions.
Explain the process of skin healing, including scar
production.
Describe the effects of aging on skin.
List the different types of burns and describe their
appearances and treatments.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-5
Learning Outcomes (cont.)
Describe the causes, signs and symptoms, and
treatments of various types of skin cancer.
Describe the causes, signs and symptoms, and
treatments of common skin disorders.
Explain the ABCD rule and its use in evaluating
melanoma.
Using the acronym CAUTION, list the seven
warning signs of cancer.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-6
Introduction

Integumentary
system consists of
skin and its
accessory organs

Accessory organs:



Hair follicles
Nails
Skin glands
Skin is the body’s outer covering and its
largest organ.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-7
Functions of the Integumentary
System

Protection

First line of defense against



Bacteria
Viruses
Protects underlying
structures from


Ultraviolet (UV) radiation
Dehydration
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-8
Functions of the Integumentary
System (cont.)

Body temperature regulation

If too hot



Dermal blood vessels dilate
Vessels carry more blood to
surface so heat can escape
If too cold


Dermal blood vessels constrict
Prevents heat from escaping
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-9
Functions of the Integumentary
System (cont.)

Vitamin D production


Sensation


Needed for calcium absorption
Sensory receptors
Excretion

Small amounts of waste products
are lost through perspiration
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-10
Apply Your Knowledge
What are the functions of the integumentary system?
ANSWER: The functions of the integumentary system are
protection, regulation of body temperature, vitamin D
production, sensation, and excretion.
Super!
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-11
Structure of Skin

Epidermis

Dermis

Hypodermis
or subcutaneous
layer
Back
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24-12
Skin Structure: Epidermis


Most superficial layer
Two parts

Stratum corneum



Outermost layer
Mostly dead cells form an impermeable layer
Stratum basale (stratum germinativum)


Deepest layer
Cells constantly dividing and pushing older cells
outward
To Figure of Skin
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24-13
Skin Structure: Epidermis (cont.)

Keratinocyte – most common

Makes and accumulates keratin


Durable protein that makes the epidermis waterproof
and resistant to pathogens
Melanocyte

Makes the pigment melanin

Traps UV radiation and prevents damage to
underlying layers of the skin
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24-14
Skin Structure: Dermis


Deeper of the two skin layers
Contains all major tissue types, plus






Sudoriferous (sweat) glands
Sebaceous (oil) glands
Hair follicles and arrector pili muscles
Collagen, elastic, and nerve fibers
Blood vessels
Binds the epidermis to the
subcutaneous tissue
To Figure of Skin
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24-15
Skin Structure: Subcutaneous Layer


Hypodermis
Composed of



Adipose (fat) and loose connective tissue
Blood vessels and nerves
Functions


Storage in adipose tissue
Cushions and insulates underlying
structures
To Figure of Skin
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-16
Apply Your Knowledge
Where are melanocytes and keratinocytes, and what is
their function?
ANSWER: Both are located in the epidermis of the skin.
Keratinocytes make and accumulate keratin, which is a
durable protein that makes the epidermis waterproof and
resistant to pathogens.
Melanocytes make the pigment melanin, which traps UV
radiation and prevents damage to underlying layers of the
skin.
Excellent!
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-17
Skin Color

Determined by amount
of melanin in the
epidermis of skin

The more melanin, the
darker the skin color

Range is from yellowish
to brownish
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-18
Skin Color (cont.)

Oxygenated blood

Amount of oxygen dissolved in the hemoglobin
of the red blood cells

Hemoglobin – a pigment in the RBCs

If blood is well-oxygenated, skin will be pink

If oxygen level in blood is low, skin will be pale
or have a bluish color (cyanosis)
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-19
Apply Your Knowledge
What affects skin color?
ANSWER: The amount of melanin produced by the
melanocytes and the oxygenation of the blood.
Nice Job!
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-20
Skin Lesions

Any variation in the
skin

As simple as a freckle

As serious as a tumor
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24-21
Skin Lesions (cont.)
Lesion Name
Description
Bulla
A large blister or cluster of blisters
Cicatrix
A scar, usually inside a wound or tissue
Crust
Dried blood or pus on the skin
Ecchymosis
A black-and-blue mark or bruise
Erosion
A shallow area of skin worn away by
friction or pressure
A scratch; may be covered with dried blood
Excoriation
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24-22
Skin Lesions (cont.)
Lesion Name
Description
Fissure
Keloid
A crack in the skin’s surface
An overgrowth of scar tissue
Macule
A flat skin discoloration, such as a freckle or
a flat mole
Nodule
A large pimple or small node
Papule
An elevated mass similar to but smaller than
a nodule
Petechiae
Pinpoint skin hemorrhages that result from
bleeding disorders
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24-23
Skin Lesions (cont.)
Lesion Name
Description
Plaque
A small, flat, scaly area of skin
Purpura
Purple-red bruises usually due to clotting
abnormalities
Scale
Thin plaques of epithelial tissue on skin’s
surface
Pustule
An elevated (infected) lesion containing pus
Tumor
A swelling of abnormal tissue growth
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-24
Skin Lesions (cont.)
Lesion Name
Description
Ulcer
A wound that results from tissue loss
Vesicle
A blister
Wheal
Another term for hive
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-25
Apply Your Knowledge
Match the following:
ANSWER:
C Keloid
___
A. A blister
A Vesicle
___
B. A crack in the skin’s surface
E Crust
___
C. An overgrowth of scar tissue
B Fissure
___
D. A small, flat scaly area of skin
F Ulcer
___
D Plaque
___
E. Dried blood or pus on the skin
F. A wound that results from tissue loss
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-26
Accessory Organs (cont.)

Hair follicles




Tube-like depressions
in the dermis of skin
Generate hairs
Alopecia (baldness)
occurs when follicles
die
Arrector pili muscles
attached to follicles
cause goose bumps

Sebaceous glands



Produce sebum to keep
hair soft
Prevent bacteria from
growing on skin
Nails


Protect the ends of
fingers and toes
Hard keratin
Diagram
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24-27
Accessory Organs (cont.)

Sudoriferous (sweat) glands


Located in the dermis of skin
Types

Eccrine



Produce watery type of sweat
Activated by heat
Apocrine



Produce thicker type of sweat with more proteins
Concentrated in armpit and groin areas
Diagram
Activated by nervousness or stress
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-28
Accessory Organs
Sebaceous gland
Hair follicle
Sudoriferous gland
Return
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24-29
Skin Healing

Injury  inflammation

Redness due to dilation of nearby
blood vessels

Swelling because vessels leak
fluid into spaces between cells

Pain because excess fluid
activates pain receptors
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-30
Skin Healing (cont.)

Inflammation promotes healing
Extra blood to area
Injury occurs
 Extra nutrients for skin repair
Blood clot
 Defensive cells
forms
Scab replaces
Clotted blood and
blood clot
other dried tissue
Collagen fibers
replace scab
Bind the edges of wound;

major component of scars
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-31
Apply Your Knowledge
How does inflammation promote healing of the skin?
ANSWER: Inflammation promotes healing by bringing
extra blood, nutrients for skin repair, and defensive cells to
the area of injury.
Correct
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-32
Skin and Aging

Skin loses firmness due to



Loss of elastic and collagen
fibers in dermis
Loss and shifting of underlying
adipose tissues
Skin color changes


Dermis becomes thinner and more transparent
Paler due to decrease in circulation
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-33
Skin and Aging (cont.)

Melanocytes decrease



Those remaining gather  “age” spots
Hair grays and becomes thinner
Decreased tolerance to temperature changes

Sudoriferous glands decrease in number


Decreased perspiration, hard to adjust to high
temperatures
Loss in adipose tissue and decreased circulation

Increased sensitivity to cold
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-34
Apply Your Knowledge
What happens to the skin in the elderly?
ANSWER: As a person ages, the skin loses firmness, skin
color changes, melanocytes decrease, and tolerance to
temperature changes decreases due to a loss of adipose
tissue and sweat glands.
Very Good!
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-35
Burns

Second leading cause of accidental death in
the U.S.

Rule of nines is used to determine severity
(degree) of burn

Burn severity:
 First-degree
 Second-degree
 Third-degree
Rule of Nines
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Rule of Nines


This method divides body into 11 areas, each
accounting for 9% of the total body surface
area
The volume of fluid lost can be estimated by
determining how much of the body surface is
burned.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-37
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
First-Degree Burns




Only the epidermis is damaged
Area becomes red and swollen
Generally, heal in 2 -3 days
Sunburn is usually a first-degree burn
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Second-Degree Burns




Involve injury to the epidermis and upper
region of the dermis
Skin is red and painful, and blisters appear
Regrowth can still occur
Ordinarily, no permanent scars result if care is
taken to prevent infection
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Third-Degree Burns





Destroy the entire thickness of the skin
Burned area appears blanched (gray-white) or
blackened
Nerve endings are destroyed, therefore, the
burned area is not painful
Regeneration is not possible
Skin grafting required
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Burns are considered critical if



Over 25% of the body has second-degree
burns or
Over 10% of the body has third-degree burns
There are third-degree burns of the face,
hands, or feet
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-43
Burns: Treatment

Do not remove anything
sticking to the burn

Do not apply butter, lotions,
or ointments

Cool with large amounts of
water

Cover with sterile sheet or
plastic bag
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-45
Skin Cancer

Basal cell carcinoma – progresses slowly and
rarely spreads to other body parts

Squamous cell carcinoma – more likely to
spread to surrounding tissues

Malignant melanoma – more aggressive and
occurs anywhere
 Most arise from melanocytes
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-46
Skin Cancer: Basal Cell Carcinoma

Signs and symptoms




New growth or sore that will not heal
Waxy, smooth, red, pale, flat, or lumpy
May or may not bleed
Treatment:


Curettage and electrodessication
Mohs’ surgery
 Cryosurgery
 Laser therapy
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-47
Skin Cancer: Squamous Cell Carcinoma

Less common than basal cell carcinoma

Found on face, lips, ears, and backs of hands

Signs and symptoms and
treatments are the same
as for basal cell carcinoma
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-48
Skin Cancer: Malignant Melanoma

Signs and Symptoms




From melanocytes
Appear on trunk, head,
neck of men
Appear on arms and
legs of women
Itches or bleeds

Treatment




Surgery and biopsy
Removal of lymph
nodes
Chemotherapy and
radiation therapy
Immunotherapy
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-49
Skin Cancer: Stages of Melanoma
Stage 0
Only found in epidermis
Stage I
Stage II
Spread to epidermis and dermis (1 to 2 mm
thick)
2 to 4 mm thick plus ulceration
Stage III
Spread to one or more lymph nodes
Stage IV Spread to other body organs or lymph nodes
far from original melanoma
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-50
Skin Cancer: ABCD Rule
A
B
C
D
Asymmetry: The mole should not become
asymmetrical
Border should not become irregular
Color should not change or become
mixture of colors
Diameter should not grow larger than the
diameter of a pencil eraser
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-51
Cancer Warning Signs
C–
A–
U–
T–
I –
O–
N–
Change in bowel or bladder habits
A sore that will not heal
Unusual bleeding or discharge
Thickening or lump
Indigestion or difficulty swallowing
Obvious change in wart or mole
Nagging cough or hoarseness
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-52
Apply Your Knowledge
True or False:
ANSWER:
Melanomas are more aggressive .
F Basal cell carcinoma is the most aggressive form of skin
___
cancer and can form anywhere.
___
T Squamous cell carcinoma is more likely to spread to
surrounding tissues.
___
T Lesions of melanoma appear on trunk, head, neck of men and
on arms and legs of women.
Borders are irregular.
F The borders of skin cancers are usually regular.
___
___
T Basal cell carcinoma progresses slowly and rarely spreads to
other body parts.
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-53
Common Skin Disorders

Alopecia



Results in hair loss
Dermatitis

Cellulitis

Inflammation of
connective tissue
in skin

Eczema


Inflammation of skin
or a rash
Chronic dermatitis
Folliculitis

Inflammation of hair
follicles
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-54
Common Skin Disorders (cont.)

Herpes simplex



Type 1 – cold sores
Type 2 – genital
Pediculosis




Herpes zoster

Shingles

Psoriasis


Head lice
Body lice
Pubic lice
Impetigo

Inherited autoimmune
disorder
Oozing skin lesions that
eventually crust over
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-55
Common Skin Disorders (cont.)

Ringworm




Tinea corporis
Tinea capitis
Tinea pedis
Rosacea


Dilation of small facial
blood vessels
Scabies


Contagious skin
condition caused by
mites
Warts

Harmless growths
caused by a virus
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-56
Apply Your Knowledge
Match the following:
ANSWER:
C Alopecia
___
A. Dilation of small facial blood vessels
___
E Folliculitis
B. Inherited autoimmune disorder
___
F Impetigo
C. Hair loss
B Psoriasis
___
D. Growths caused by a virus
___
A Rosacea
E. Inflammation of hair follicles
___
D Warts
F. Oozing skin lesions
Right!
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
24-57
In Summary:


First line of defense for body
Protects the body from






Invading organisms
Chemicals
UV light
Water loss
Regulates body temperature
Understanding this system can help you be more
effective in your role
© 2009 The McGraw-Hill Companies, Inc. All rights reserved