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Integumentary System
Structure, functions and appendages
Disorders of the skin: burns, moles,
other problems
INTEGUMENTARY
SYSTEM
Includes skin covering surface of body
and specialized derivatives of skin such
as nails, hair, sebaceous & sweat glands.
Functions of skin
1) Protection of underlying
tissues
2) Prevents desiccation
3) Provides insulation (hair and
feathers)
4) Increases heat loss by
changes in hair or feather
position or by increased
evaporative water loss
(sweating)
5) Reception of tactile, thermal
or pain stimuli
6) Removal of excess water
and salts
7) Production of vitamin D
Structure of the skin
Normal skin is composed
of two layers: the
epidermis (outermost
layer), the dermis (middle
layer), and below is
hypodermis (innermost
layer). The layered nature
of the skin results from a
vertical arrangement of the
different types of cells.
Skin Structure
Two primary layers:
epidermis – outermost
dermis – deeper and thicker of the two
Under the two primary layers is the
hypodermis (subcutaneous layer)
Integumentary System
Commonly called the skin, it enwraps the body
and serves several purposes:
• offers protection (first line of defense) to the
underlying layers from the sun,
infection, harmful chemicals, cut and tears
• serves in body temperature regulation almost
3000 calories of body heat per day
• sense organ activity respond to temperature,
touch, pressure, and pain
Temperature Regulation
The integumentary system aids in homeostasis
(the bodies natural temperature regulation) by
providing a barrier against cold air. Skin also
blocks breezes, water, snow, etc. from entering
the body. Thus the body is able to stay
warmer. However unlike a typical man-made
jacket, which also provides protection against
the elements your skin is completely
breathable. The pores in skin allow the
entrance of certain useful molecules, but not
harmful ones.
Hair
Our skin is able to sense insects on the skin
before they are able to sting. The hair on the
head serves to control and prevent heat loss
as well as guard against sunlight and physical
trauma. Hair is produced by hair follicles in
the skin. These follicles are heavily
vascularized and are surrounded by nerve
fibers. Goose bumps occur when small
muscles pull the follicles upright producing a
bump on the surface of the skin.
Sweat Glands
Sweat glands are distributed throughout
the skin. Their basic function is to cool
the body. This is accomplished by
evaporation. Evaporation of sweat off of
the body dissipates body heat.
Pigmentation
Three pigments determine skin color:
melanin, carotene, and hemoglobin.
However, only melanin is made in the
skin. Melanin can be gradated into
many different shades. It is this ability
of Melanin that gives different races
different skin coloration.
Melanin
A special type of cells known as melanocytes
produces melanin. Melanocytes are primarily
found in the stratum germinativum. Whenever
the skin has had an exposure to sunlight, the
stratum germinativum cells, phagocytize or eat
the skin pigment melanin. After an amount of
time, melanin accumulates within the stratum
germinativum cells, and tends to form a
protective pigment "umbrella.” These
“umbrellas” of melanin pigment shields DNA from
the damaging effects of ultraviolet radiation.
Skin Cancer
When there is a lack of melanin, the
DNA, or RNA, will be in direct contact
with ultraviolet radiation, which can
cause cancer or another type of adverse
impact upon the skin.
Carotene and Hemoglobin
Carotene has a yellow-orange color and
is primarily found in the palms and the
soles. Hemoglobin gives fair-skinned
people a pink hue to their skin due to
the lack of melanin in the epidermis,
which makes it almost transparent.
•Asymmetry of shape: one half does not
look like the other
•Border is irregular: scalloped, notched,
discontinuous
•Color is uneven: multiple shades
ranging from white to tan to brown to
black occasionally some red as well
•Diameter is larger than 6mm in most
cases
•Enlargement: gradual increase in size
and elevation
Malignant Melanoma
• a proliferation of markedly atypical melanocytes
with the potential for dermal invasion and
widespread metastasis
• several clinical subtypes have been described, but
the prognosis for all subtypes depends on the
histologic thickness (Breslow level) of the tumor
• sun exposure is an important predisposing
factor,
• most lesions arise de novo, but some arise from
"precursor lesions" such as large congenital nevi
or "dysplastic" nevi
Basal Cell Carcinoma: clinical
•most common human cancer: more than 400,000 new
patients annually
•found most commonly on sun-exposed areas of fairskinned, sun-damaged individuals
•translucent, "pearly" or "waxy" papule; associated
telangiectasia, sometimes central ulceration
•locally destructive, very rarely metastasizes; can cause
death
•sun-exposure, ionizing radiation, immunosuppression
are all predisposing factors
•several clinical and histologic subtypes
Squamous Cell Carcinoma
•malignant tumor of epithelial keratinocytes – skin
and mucous membranes
•induced by various carcinogens, but in the skin
SUN EXPOSURE is the most common
•ionizing radiation, oncogenic viruses such as
certain wart viruses, arsenic ingestion, chronic
wounds also induced cutaneous SCC
•usually arises as solitary, keratotic or eroded, pink
papule or nodule – persists and grows
•may arise from a precancerous actinic keratosis
•SCC arising in sun-damaged skin less prone to
metastasis than mucosal SCC
Burns: rule of nines
An injury to the layers of the skin by fire, chemicals,
electricity, steam, and radiation.
• 1st degree burn is when the top
layer of skin or, epidermis, is
slightly burned, producing pain
and redness
• 2nd degree burns injure the
second layer of skin called the
dermis and result in redness,
pain, and blisters.
• 3rd degree burns damage
involves all layers of the skin,
which appears charred black,
and could be dry and white in
some spots.
Rule of nines
This method divides the body into eleven specific
sections, each of which comprise approximately 9%,
or multiples of 9%, of the patient’s body surface
area. These areas are the head and neck, the front
of the chest, the front of the abdomen, the posterior
chest or upper back, the posterior abdomen or lower
back, the anterior surface of each lower extremity,
the posterior surface of each lower extremity, and
each upper extremity. The genitalia account for the
remaining one percent.
Burns
•
•
•
•
normal - fig. 1
1st degree – fig. 2
2nd degree – fig. 3
3rd degree –fig. 4
First Aid for burns
According to the Burn Unit,
there are five categories of
burn depth.
They are
•first-degree
•second-degree partial
thickness
•second-degree deep partial
thickness
•third-degree full thickness
•fourth-degree full thickness.
For most burns:
• Calm and reassure the
victim.
• Dowse area with cool
water. Do not apply ice.
• Remove any
constricting clothing and
jewelry, if it comes off
easily.
• Never use butter, oils,
or ointments on severe
burns.
First-degree and most seconddegree burns
• Flush or soak the burn in cool water for several minutes.
• For minor burns, apply antibacterial ointment after the
burn has cooled.
• Cover the burn with a sterile bandage or clean cloth.
• If necessary, give the person pain medication such as
acetaminophen or ibuprofen.
• Seek medical attention if the burn is more than 2 to 3
inches in diameter.
Third-degree burns -including
electrical burns
• Make sure the victim is breathing and
begin CPR if necessary. See CPR for
more information.
• Call 911 immediately
• To prevent shock, lay the victim flat,
elevate the feet about 12 inches, and
cover with a coat or blanket.
Chemical burns
• Flush chemicals thoroughly for 15 to 30
minutes with water.
• Remove contaminated clothing, if
possible.
• Do not attempt to neutralize the burn
with a reciprocal chemical.
• Call 911 immediately.
Three layers
A/B Epidermis = upper layer,
ectodermal origin; specialized
epithelium composed of
stratified squamous, can be
thick or thin depending on
stresses on that area of skin,
can also be keratinized or
nonkeratinized
C Dermis = below epidermis,
mesodermal origin, dense
irregular CT, thicker than
epidermis; sensory endings
(tactile, thermal, pain) found
throughout underlies dermis,
areolar to adipose CT,
connects skin to structures
underneath
Appendages
A. epidermis
B. dermis
C. Subcutaneous
D. vascular tissue
E. sebaceous glands
F. hair hair follicle - root, shaft, bulb
G. receptors,
H. sweat glands
References
“Current Concepts In Burn
Therapy,”Ken Forinash, BS, NREMT-PEMS
Coordinator, Cunningham Fire Protection
District, Denver, CO
www.vfre.com/Presentation20/