Skin

7,
Date
Name
Class
S~E.G>f[0N. 2.-4^
ill
Guide for
Reading
• What are the functions of skin?
• What habits can
help keep your
skin healthy?
50 • D
T
he skin performs several major functions i n the body. The skin
covers the body and prevents the loss of water. It protects the
body from injury and infection. The skin also helps to regulate body
temperature, eliminate wastes, gather i n f o r m a t i o n about the environment, and produce vitamin D.
The skin is organized into two main layers, the epidermis and'the
dermis. The epidermis is the outermost layer of the skin. The epidermis
does not have nerves or blood vessels. Cells i n the epidermis have" a definite
life cycle. New cells f o r m deep i n the epidermis, gradually mature, and
move upward. When these cells die, they become part of the surface layer
of the epidermis. Soon, these cells are shed and replaced by the dead cells
below them. Cells deep i n the epidermis produce melanin, a pigment, or
colored substance, that gives .skin its color..The more melanin i n your
skin, the darker i t is. Melanin production helps to protect the skin f r o m
burning.
The dermis is the lower layer of the skin. I t contains nerves, blood
vessels, sweat glands, hairs, and oil glands. Sweat glands produce perspiration, which reaches the surface through openings called pores. Strands
of hair grow within the dermis-in structures called follicles. Oil produced
i n glands around the hair follicles waterproofs the hair. I n addition, oil
helps to keep the skin moist. .
Four simple habits can help you keep your skin healthy. Eat properly.
D r i n k enough water. l i m i t your exposure to the sun. Keep your skin
clean and dry.
Cancer is a disease in- which some body cells divide uncontrollably.
Repeated exposure to sunlight can damage skin cells' and cause them to
become cancerous.
When oil glands become clogged with oil, bacterial infections can occur. •
One bacterial infection of the skin that can be difficult to control is known
as acne. Washing your skin will help control oiliness and keep your skin
f r o m becoming infected with more bacteria.' Other organisms, called fnngi,
can also live on and infect the skin. Athlete's foot is a' very common fungal
infection that occurs on the feet, especially between the toes.
Teaching Resources
Human Biology and'Health
Date
.Name
SECTION 2-4
Class
R E V I EW A H DI If ET MrFOIfC-E^
The Skin
•- Understanding Main Ideas
Answer the following questions in the spaces
provided.
1. List me'functions of the skin.
2. How do the dead cells of the epidermis help the body?
3. What.structures does the dermis contain?
=j 4. How can you help to keep your skin healthy?
• Building Vocabulary
Use the vocabulary below to label the following
pore
epidermis
hair follicle
diagram.
dermis
5.
Human Biology and Health
Teaching Resources
D • 51
Name -
Date
Class
All burns are not the. same. Doctors classify burns according to the depth of skin
damage. Burns can be first-, second-, or third-degree as shown in the figure below.
Epidermis
•1st degree j
2nd degree
Dermis
3rd degree
Subcutaneous
First-degree burns are caused by briefly touching a hot object or corning into
contact with hot water or steam. A m i l d sunburn is also considered a first-degree
" burn. I n a first-degree burn, only the epidermis is damaged. These burns make
the skin turn red and swell slightly.
Second-degree burns are caused b y coming into contact with flames,, spilling a
• very hot liquid on yourself, or a deep sunburn. I n a. second-degree burn, both the
•. epidermis and the dermis are damaged These burns turn me skin bright red and
cause blisters. These burns are very painful.
' ' . - . . •
• 'Third-degree burns are also caused by contact with flames or spilling'hot liquids
.on yourself. I n a third-degree' burri, the entire thickness of the skin is damaged, '
>incmding blood vessels, sweat glands, sebaceous glands, hair follicles, and'other '
skin tissues and structures. These burns are often leathery i n appearance and may.
be red, white, tan, or brown i n color. There is'no pain, because even the skin's
pain receptors are damaged;
;
Answer the following questions on a separate sheet ofpaper.
• JL/What part of the skin is affected by a first-degree burn? By a second-degree burn?
•' 1~. -List "at least four'things destroyed by a third-degree burn.
%. Because the skin is destroyed in-third-degree, burns, what would be one
possible complication of these burns while the patient is recovering? Explain .- •
your answer:
•'
..
•• •
.
•
£•.. Many burns occur i n the kitchen. What'are two things you can do to prevent
. •* b u r n accidents diere?
52 •• D
Teaching Resources
Human Biology ant] Health'
3¬
13
o' .
CD .
X
3
O

Download Report