CHAPTER 6
INTEGUMENTARY SYSTEM
OVERVIEW
This chapter begins with a definition of an organ and names the iarge organ of the integumentary system (Leaming Outcome 1).
The chapter continues with a discussion ofthe skin including the general functions ofskin, descriptions ofthe layers ofthe
skin, and the factors that determine skin color, identifying the accessory structures of the skin and their function (Learning
Outcomes 2-6). The role ofthe skin in the regulation ofbody temperature and the life-span changes in the skin are described
(Learning Outcomes 7, 10). Last, the events ofwound healing and the healing ofvarious types ofburns are addressed (Learning
Outcomes 8, 9).
Study of the integumentary system is essential to understanding how the body controls interaction between the intemal and
extemal environments.
LEARNING OUTCOMES
After you have studied this chapter, you should be able to:
6.1 Introduction (p. 171)
1. Define organ andname the large organ of the integumentary system.
6.2 Skin and Its Tissues (p. 171)
2. List the general functions of the skin.
6.3
6.4
6.5
6.6
3.
4.
Describe the structure of the layers of the skin.
Summarize the factors that determine skin color.
Accessory Structures of the Skin (p. 177)
5. Describe the accessory structures associated with the skin.
6. Explain the functions ofeach accessory structure ofthe skin.
Regulation of Body Temperature (p. 181)
7. Explain how the skin helps regulate body temperature.
Healing of Wounds and Bums (p. 183)
8. Describe the events that are part of wound healing.
9. Distinguish among the types of burns, including a description of healing with each type.
Life-Span Changes (p. 186)
10.
Summarize life-span changes in the integumentary system.
FOCUS QUESTION
You have spent the day on the beach in 90'F heat. You retum to your air-conditioned home and notice that you have several
insect bites that you have scratched open. How does the skin help you to adjust to the changes in temperature and prevent a
systemic infection?
MASTERY TEST
Now take the mastery test. Do not guess. Some questions may have more than one cor:rect answer. As soon as you complete the
test, correct it. Note your successes and failures so that you can read the chapter to meet your leaming needs.
l.
Define an organ.
2.
3.
List the functions of the skin.
The largest organ in the body by weight is the
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4.
5.
6.
7.
The outer layer ofskin is ca1led the
The inner layer ofskin is called the
The masses ofconnective tissue beneath the inner layers ofskin are called the
The cells ofthe skin that reproduce are in the
a.
b.
8.
stratum comeum.
c.
d.
epidermis.
c.
subcutaneous layer.
stratum basale (germinativum).
Blood vessels supplying the skin are located in the
a.
b.
9.
keratin.
demis.
epidermis.
When a person does not change his or her position for a long time, a
may
develop.
10.
The symptoms of psoriasis are due to
a.
b.
1
1.
increased cell division in the
epidermis.
cells.
increased keratinization of epidermal
impaired circulation to the epidermis.
c.
d.
biliverdin.
The fingerprints of identical twins are identical.
True
False
14.
15.
The dermis of the skin (contains/does not contain) smooth muscle cells.
16.
17.
18.
Hair is composed of
The accessory organs ofthe skin are
_.
Hair color is determined bv the amount of
glands
c.
d.
apocrme
endocrine
endocrine
eccrine
Mammary glands are modified
c.
d.
exocrlne
c.
d.
contact dermatitis
c.
d.
muscles
c.
d.
evaporation.
c.
d.
young adults.
apocrin
glands.
The most common skin problem in adolescence is
cancers.
Which of the following organs and tissues produce the most heat?
a. kidneys
b. bones
lungs
The primary process by which the body loses heat is
a. radiation.
b. conduction.
25.
exocrine
The sweat glands associated with the regulation of body temperature are the
a. acne.
b. blisters.
24.
sebaceous
The active, growing part of the nail is the
a.
b.
23.
and
it contains-
The glands usually associated with hair follicles are
a.
b.
21.
22.
bilirubin.
Skin cancer is associated with high exposure to
a.
b.
19.
20.
separation of the dermal and epidermal
layers.
The pigment that gives color to the skin is
a. melanin.
b. trichosiderin.
12.
13.
c.
d.
convection.
Those at highest risk for hypothermia are
a. infants.
b. school-age children.
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the elderly.
glands.
26.
The person with a low concentration ofoxygenated blood has a skin condition known as
a. hyperemia.
b. eccymosis.
27.
c.
When a cut extends into the dermis, the celis that form the new tissue to hold the edges of the wound together are
a. reticulocl.tes.
b. fibroblasts.
28.
29.
30.
1
.
c.
d.
phagocytes.
neutrophils.
In large, open wounds, the healing process may be accompanied by the formation of
When large areas of the epidermis are destroyed by a bum, the cells are replaced by
a.
stem cells ofaccessory organs ofthe skin,
such as hair follicles or glands.
b.
the dermis.
c.
d.
the stratus germinativum.
none
ofthe above
A fuIl-thickness burn requires skin grafting in order to supply skin cells usualiy produced in the dermis.
a.
b.
3
cyanosis.
True
False
Skin changes in the elderly affect the sfiucture of bones adversely.
a.
b.
True
False
STUDY ACTIVITIES
Definition of Word Parts (p. 170)
Define the following word parts used in this chapter.
albcutdermepi-
follicholkeratmelan-
porseb-
6.1 Introduction (p. 171)
A.
What constitutes an organ?
B.
What is the heaviest organ in the body?
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C.
What are the defining characteristics of the skin?
6.2 Skin and Its Tissues (p. 171)
A.
List the functions of the skin.
B.
What kinds of tissue are found in the skin?
C.
The layers of the skin are the
D.
Describe the structure and function of the subcutaneous layer.
E.
Describe the ways in which drugs can be delivered through the skin
F.
Fill in the following chart.
and
Layers of the Epidermis
Layer
Location
Characteristics
Stratum basale
Stratum spinosum
Stratum granuiosum
Stratum lucidum
Stratum corneum
G.
Why is water not absorbed through the skin?
H.
How is the production of epidermal ceils related to the development of calluses and coms?
I.
Answer the foilowing questions about pressure sores (decubitus ulcers).
J.
1.
How does a pressure sore develop?
2.
How can the development ofpressure sores be prevented?
3.
Would you expect a very thin person to be at increased risk for
List the functions of the epidermis.
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a pressure sore?
Why?
K-
Describe the process by which epidermal cells acquire melanin
L.
Cancer
M
What factors determine skin color?
N
How do the pattems of fingerprints form?
o.
Describe the structure and function of the dermis.
ofthe skin can arise from the deep layers ofthe
What tlpes of muscle cells are found in the dermis?
a
What is the function of nerve tissue in the skin?
R.
Describe the subcutaneous layer ofthe skin.
6.3 Accessory Structures of the Skin (p. 177)
A.
Label the numbered leader lines on the drawing below.
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or from pigmented
B.
Answer the following questions about hair formation.
1.
How is hair formed in this follicle?
2.
What is folliculitis?
3.
Describe several forms ofbaldness.
4.
How is baldness treated? How effective are the various treatments for baldness?
5.
Explain how various hair colors are produced.
C.
Describe how hair responds to cold temperature or strong emotion.
D.
Answer the following questions concerning nails.
1
.
2.
Where is the growing portion of the nail located?
Discuss the clinical significance
ofthe appearance ofthe nails.
E.
Where are sebaceous glands located, and what is the function of the substance they secrete?
F.
Compare apocrine and eccrine sweat glands in relation to location, association with other skin structures, and activating
stimuli.
G.
Describe the mechanisms that lead to acne. How is it treated?
6.4 Regulation of Body Temperature (p. 181)
A.
Match the terms in the first column, which are processes of heat loss, with their definitions in the second column.
_
_2.
1. radiation
conduction
Heat is lost by continuous circulation ofair
over the body.
b.
Sweat changes to vapor and carries heat
away from the body.
c
_3.convection
_4.
a.
d.
evaporation
ffxlffiHffiln"T:Tbodvtocooler
Heat moves away from the body by contact
with a cool object.
B.
Describe the roles of the nervous, muscular, circulatory, and respiratory systems in heat regulation.
C.
Explain the events that can produce an increase in body temperature.
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D.
1.
What are the symptoms of hypothermia?
2.
What groups are at increased risk of hypothermia?
3.
How can hypothermia be prevented?
6.5 Healing of Wounds and Burns (p. 183)
A.
B.
Describe the process of healing in the following wounds.
1.
a shallow break in the skin
2.
an injury that extends into the dermis or subcutaneous layer
3.
alarge, openwound
Describe the injury and healing process in each of the following conditions
1.
superficialpartial-thicknessbums
2.
deep partial-thickness bums
3.
full-thickness burns
6.6 Life-Span Changes (p. 186)
Describe the changes that occur as skin ages.
Clinical F ocus Question
As summer and the hot weather approach, your family is concemed about your grandmother. Yow grandmother is a healthy, 83year-old woman who lives alone and is proud of her independence. She does not have an air conditioner, despite your family's
offer to purchase and install one for her. She says she is too old to get used to "newfangled things now." What suggestions could
you offer to help your grandmother maintain her health during the hot weather? Explain your rationale.
When you have completed the study activities to your satisfaction, retake the mastery test and compare your performance with
your initial attempt. Ifthere are still areas you do not understand, repeat the appropriate study activities.
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