Transcript The Integumentary System

The
Integumentary
System
SKIN
The Integumentary System
 On
average, adult skin covers over 3,000
square inches of surface area and
accounts for about 15% of the total body
weight.
 Skin is the largest organ of the body.
 Epidermal cells live about 2-4 weeks and
as humans, we are constantly shedding
dead skin cells.
More skin Facts
 You
replace the entirety of your skin
approximately every 15 years.
 30,000 to 40,000 dead skin cells fall off per
minute, resulting in about 8.8 pounds of dead
skin cells fall off your body per year.
 75-90% of household dust is composed of dead
skin cells.
 About 80 percent of the material seen floating
in a sunbeam is, in fact, flakes of dead skin.
 You can drastically reduce the amount of dead
skin contributing to dust in your home by
exfoliating 3-4 times per week when you bathe.
A. Layers of Skin
 Epidermis-
The outermost layer of skin that
is made up of 5-6 layers and contains no
blood vessels.
 Two main layers of epidermis:


1. Stratum corneum- The outermost layer
where cells constantly shed.
2. Stratum germinativum- Provides cells to
replace cells in the strata corneum.
Epidermis Pic
2. Dermis
 The
dermis is also called the dorium or true
skin.


A. It has a framework of connective tissue
that contains blood vessels, lymph vessels,
nerves, involuntary muscle, sweat and oil
glands, and hair follicles.
B. The top of the dermis is covered with
papillae.
Dermis continued
 Papillae-
are elevations of the dermis that
fit into ridges on the stratum germinativum
of the epidermis. (Goose bumps!!!!)



1. The ridges that the papillae fit into form
lines or striations on the skin.
2. The pattern of ridges makes our finger
prints and foot prints and is unique for each
individual.
3. The friction ridge skin helps us GRIP
things.
Fingerprints
 Fingerprints
begin to form in the womb
during the 3rd or 4th month of gestation.
During this time the middle layer of skin,
called the basal layer, begins to outgrow
the inner dermis and epidermis skin layers.
 It is believed that the buckling and
folding of this skin layer is partially
responsible for the unique stresses in
fingertip pads that become visible as the
fetus continues to develop.
Fingerprints continued
 The
first identifying marks that occur on a
fetus's skin are called ridges. Ridges are
the faint lines on the fingertips that create
the foundation of a fingerprint.
 As a fetus touches surrounding structures,
her exact position in the womb and the
density of the womb's amniotic fluid
determine how every individual ridge will
form.
 The level of activity of a fetus and the
general chaos of the conditions of the
womb prevent fingerprints from
developing the same way in fetuses.
I want to get rid of my prints
 Getting
rid of your prints is harder than
you think. Prints originate in the Dermis.
This is why you can’t shave or cut them
off. To do so you must cut all the way
past the dermis (almost to the bone).
OUCH!!!
 Any significant cuts on your fingers will
simply result in scarring and will make you
even more unique.
How about using acid to get
rid of my prints???
A
famous gangster by the name of John
Dillinger tried that method.
 It was a dismal failure and quite painful as
well.
 All it did was give Mr. Dillinger some pretty
unique scars. 
3. Hypodermis or
Subcutaneous fascia
 The
innermost layer of skin which
connects skin to the underlying muscles.
 It is made of elastic and fibrous
connective tissue and adipose (fatty)
tissue.
B. Glands of the Skin
 1.
Sudoriferous glands- aka. Sweat glands
are coiled tubes that extend through the
dermis and open on the surface of the
skin at an opening called a pore.
Sweat glands continued



A. Sudoriferous glands function to eliminate
sweat or perspiration that contains water,
salts, and some body wastes.
B. Sweat contains body wastes and is
basically odorless. When sweat interacts
with bacteria on skin, body odor occurs.
C. The process of perspiration removes
excess water from the body and cools
body as sweat evaporates into the air.
2. Sebaceous glands
 A.
Sebaceous glands, also called oil
glands, usually open onto a hair follicle.
 B. Sebaceous glands produce oil called
sebum.
Oil glands continued
 1.
Sebum keeps hair from becoming dry
and brittle and is slightly acidic so it acts
as an antibacterial and antifungal
secretion to help prevent infections.
 2. A blackhead or pimple occurs when
oil glands become plugged with dirt and
oil.
Blackhead VS. Whitehead

Blackheads- If there is a
 Whiteheads form
plug of cells in the pore
when the pore is
and the pore opening
totally blocked,
expands, so that it's not
and the growing
entirely blocked off, then a
matter has forced
blackhead appears. The
portion of the comedo that
the comedo
is nearest the surface has a
(blockage) to just
concentration of melanin,
beneath the
giving it its appearance
surface of the skin.
and appropriate name.
Zits (pustules)
 Pustules.
Less-scientific circles commonly
refer to pustules as "zits." These are the
pus-filled pimples that form in your follicles
and sweat glands.
C. Other Parts of the
Integumentary System
 1.
Hair- consists of a hair shaft and a root
that grows in a hollow tube called a
follicle.
More about hair
 A.
Hair helps protect the body and
covers all body surfaces except the palms
of the hands and feet.
 B. Alopecia- aka. Baldness is a genetic
condition that is common in men, but can
also occur in women and involves the
permanent loss of hair on the scalp.
Cool hair facts
 It
is normal to lose 40-100 hairs a day.
 A human hair on your head can live for 37 years.
 Only 90% of your hair follicles are active at
a time. The other 10% are in a rest phase.
 On average, the scalp contains 100,000
strands of hair. That’s 1000 hairs per
square inch.
 One strand of hair can carry a weight of
100 grams.
2. Nails
 Nails
are made of dead keratinized
epidermal epithelial cells, which are
packed closely together to form a thick
dense surface.
Nails continued
 A.
Nails function to protect the fingers
and toes from injury.
 B. Nail cells form in the nail bed and will
continue to grow and regrow as long as
the nail bed is not damaged.
Cool Nail Facts
 The
longest nail was on a man from India
and it measured 4 feet long!!!
 Men’s nails grow faster than women’s.
 The middle fingernail grows fastest and
the thumb nail grows slowest.
 Nails, like hair, grow faster in warmer
climates.
 How fast do nails grow? A lot of factors
influence the rate, but a general rule is ½
to 4 inches per year.
 Onychophagia is the scientific term for
nail biting.
D. Functions of the
Integumentary System
 1.
Protection- It serves as a barrier for
sun’s ultraviolet rays, protects against
invasion of pathogens or germs, and
holds moisture in preventing deep tissues
from drying out.
 2. Sensory perception- Nerves present in
the skin responds to pain, pressure,
temperature, and touch sensations.
Functions continued
 3.
Regulation of body temperature- Blood
vessels in the skin help retain or release heat.
 A. When blood vessels dilate, they allow excess
heat to escape through the skin.
 B. When blood vessels constrict, they retain
heat.
 C. Sudoriferous (sweat) glands also help cool
the body through evaporation of perspiration.
More Functions



4. Storage- Skin has tissues for temporary
storage of fat, glucose, water, vitamins, and
salts. Stores adipose tissue in subcutaneous
fascia, which is a source of energy.
5. Absorption- certain substances are
absorbed through the skin. This is called
transdermal absorption.
Ex. Medications for motion sickness,
nitroglycerine for heart trouble, and nicotine
patches to help a person quit smoking.
Couple More Functions
 6.
Excretion- Helps the body eliminate
salt, wastes, and excess water through the
act of perspiration.
 7. Production- Skin helps in production of
vitamin D by using the ultraviolet rays fro
the sun to form an initial molecule of
vitamin D that matures in the liver.
E. Skin Color
 1.
Pigmentation- Skin color is inherited
and determined by pigments in
epidermis.
 A. Melanin- is a brownish-black pigment
produced in the epidermis by specialized
cells called melanocytes.
 B. Everyone has the same number of
melanocytes. Genes present in each
racial group determine the amount of
melanin produced.
More about melanin
 C.
Melanin causes a black, brown, or
yellowish skin tint depending on racial origin
and the amount of melanin produced.
 D. Ultraviolet light activates melanocytes to
produce more melanin to protect and tan
the skin.
 E. Small concentrated areas of melanin
pigment form freckles.
 F. Carotene- yellowish-red pigment tat also
helps determine skin color.
More about
Pigments!!!! Get it??
 2.
Albino- absence of color pigments
producing skin that has a pinkish tint, hair
that is pale yellow or white, and eyes that
are red in color and are very sensitive to
light.
Red pigments
 3.
Abnormal colors A. Erythema- reddish color caused by
burns or a congestion of blood in vessels.
Yellow pigments
 B.
Jaundice- yellowish discoloration that can
indicate the presence of bile in blood as a
result of liver or gallbladder disease. Also seen
in certain diseases that involve destruction of
red blood cells.
Blue Pigments
 C.
Cyanosis- bluish discoloration caused by
insufficient oxygen and is commonly
associated with heart, lung, and circulatory
diseases.
Gray or Brown Discoloration
 D.
Gray or Brown Discoloration- signs of
chronic poisoning.
F. Skin Eruptions

1. Macules (macular rash)- flat spots on the
skin. Ex. Freckles
More Skin
 2.
Papules (popular rash)- firm raised areas as
in pimples and stages of chicken pox.
More Eruptions
 3.
Vesicles- blisters or sacs full of fluid.
Krakatoa
 4.
Pustules- Sacs filled with pus.
SCABS
 5.
Crusts- areas of dried pus and blood
commonly called scabs.
Hives and Insect Bites
 6.
Wheals- Itchy elevated areas with an
irregular shape often seen in hives and insect
bites.
Ulcers
 7.
Ulcers- Deep loss of skin surface that may
extend into the dermis and may cause periodic
bleeding and formation of scars.
G. Diseases and abnormal
conditions
 1.
Acne vulgaris- inflammation of sebaceous
glands usually occurring during adolescence as
a result of hormonal changes and increased
sebum.
 A. Symptoms- include papules, pustules, and
blackheads all occurring when hair follicle
becomes blocked with dirt, cosmetics, excess oil
and/or bacteria.
 B. Treatment- frequent thorough washing of
skin, avoid creams and heavy makeup,
antibiotics or vitamin A ointment, ultraviolet light
treatments.
More Diseases
 2.
Athlete’s Foot- Contagious fungal infection
usually on the feet.
 A. Symptoms- itchy skin, blisters, and cracks
which may turn in to open sores.
 B. Treatment- antifungal medication, keep area
dry and clean.
Diseases continued…
 3.
Cancer- has many causes and occurs in
different forms.
 A. Causes/ indicators



1. A mole that changes in color, shape, size, or
texture.
2. Bleeding or itching of mole.
3. Exposure to the sun, prolonged use of tanning
beds
4. Irritating chemicals or radiation.
B. Treatments- involve surgical removal of the cancer, radiation,
and/or chemotherapy
Cancer Continued…
 C.
Types of Cancer:
 1. Basal Cell Carcinoma- Cancer of the basal
cells in the epidermis of the skin which grows
slowly and usually does not spread.

Lesions can be pink to yellow-white and are
usually smooth with a depressed center having
an irregular shaped border.
Cancer Continued…
 2.
Squamous Cell Carcinoma- affects the thin
cells of the epithelium but can spread quickly to
other areas of the body.


Lesions start as small, firm, red flat sores that later
scale or crust.
Sores that do not heal are frequently squamous
cell carcinomas.
Cancer continued…
 3.
Malignant Melanoma- Develops in the
melanocytes of the epidermis and is the most
dangerous type of skin cancer.


Lesions can be brown, black, pink, or
multicolored.
They are usually flat or raised, slightly asymmetric,
and irregular or notched on the edges.
More Diseases and Abnormal
Conditions
 4.
Dermatitis- Inflammation of the skin.
 A. Caused by any substance that irritates the
skin such as an allergic reaction to detergents,
cosmetics, pollen, or certain foods.
 B. Contact Dermatitis- is caused by contact with
poison ivy, poison sumac, or poison oak.
 C. Symptoms of dermatitis include dry skin,
erythema, edema, itching, macular-papular
rashes and scaling.
 D. Treatments- eliminate allergen, use antiinflammatory ointment, antihistamines, and
steroids
More Diseases and Abnormal
Conditions
 5.
Eczema- noncontagious inflammatory skin
disorder.
 A. Caused by a reaction to allergen or irritant,
diet, cosmetics, soaps, medications and/ or
emotional distress.
 B. Symptoms include dryness, erythema,
edema, itching, vesicles, crusts, and scaling
 C. Treatment includes removing the irritant and
applying corticosteroids.
Some More D.A.A.C.
 6.
Impetigo- highly contagious streptococcal or
staphylococcal skin infection.
 A. Symptoms include dryness, erythema, oozing
vesicles, pustules, formation of yellow crusts.
 B. Treatment includes washing lesions with soap
and water, keep dry, use topical and oral
antibiotics.
Still More D.A.A.C.
 7.
Psoriasis- Chronic, noncontagious, inherited
skin disease characterized by periods of
exacerbations (symptoms present) followed by
remission (symptoms decrease or disappear).
 A. Although the cause is hereditary, symptoms
tend to be exacerbated by stress, cold weather,
sunlight, pregnancy, and endocrine changes.
 B. Symptoms include red thick areas covered
with white or silver scales.
 C. Treatment- NO CURE, chronic condition.
Coal tar, cortisone ointments, ultraviolet light,
and removal of scales can help with symptoms.
And Some More D.A.A.C.
 8.
Ringworm- highly contagious fungus
infection of the skin or scalp.
 A. Symptoms include flat or raised circular area
with clear central area surrounded by an itchy,
scaly, or crusty outer ring.
 B. Treatment includes oral and topical
antifungal medications.
Last D.A.A.C.
 9.
Verrucae or Warts- Viral infection of the skin.
 A. Symptoms include the formation of rough,
hard, elevated, rounded surface on the skin.
 B. Plantar warts- usually occur at pressure
points on the soles of the feet.
 C. Treatment includes the removal with
electricity, liquid nitrogen, acid, chemicals, or
laser. Some disappear spontaneously.