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Integument System
• Integument System
–Organs
• Skin
• Hair
• Nails
• Glands

Integument System
• Functions
– Protection
–Abrasion
–Infection
–UV light
–Dehydration
– Thermal Regulation
–Insulation
–Cooling
– Sensory Reception
– Vitamin D Production

The Skin and the Hypodermis
Skin – our largest organ
– Accounts for 7% of body weight
– Divided into three distinct layers
• Epidermis
• Dermis
• Hypodermis – lies deep to the dermis

Skin Structure

Figure 5
...

• Varies in thickness from a few to dozens of cells
thick (eyelids to palms)
• It does not have any vascularization, so it relies
on absorbing oxygen and nutrients from the
blood vessels in the connective tissues deep to
it
...


Layers of the Epidermis (5)
• Stratum basale (the deepest layer of
epidermis)
• Stratum spinosum
• Stratum granulosum
• Stratum lucidum (only in thick skin
palm and sole)
• Stratum corneum (most superficial layer of
epidermis)

STRATUM BASALE: has 3 types of cells
• Main cell type is KERATINOCYTES
– Keratin is a protein, is waterproof and
strong
• MELANOCYTES produce MELANIN (dark
brown pigment)
– Everyone has the same number of
melanocytes
– Improper function causes light skin
• MACROPHAGES (ingest and destroy cells)

• The cells present in skin are
keratinocytes(80%), melanocytes,
langerhans cells & merkel cells

Epidermal Cells and Layers of the
Epidermis

Figure 5
...
Basale,
the older cells get pushed up and become
the S
...

basale, the S
...
granulosum layer
...
granulosum begin to
die because they are now too far from
nutrient source (in dermis)
• After they die, they start to fill up with
KERATIN

KERATIN
• Keratin is a waxy protein substance only
found in the epidermis
...

• It can absorb water, so keratin swells when
soaking wet
...
The water
evaporates when you dry off, and pulls more
water out of your body, so soaking in the tub
will dry your skin out…unless you put lotion on
right away to keep the water in the epidermal
and dermal layers
...


STRATUM CORNEUM
The main difference between thick skin and thin
skin relates to the thickness of the Stratum
corneum
...
In the stratum
corneum the cells lose their nucleus and fuse to
squamous sheets, which are eventually shed
from the surface (desquamation)
...
5 grams
They are the major source of dust in the house

STRATUM LUCIDUM
This layer is only on the palms and
soles
It is just deep to the S
...
granulosum
The dead cells in the layers above
them can’t flake off fast enough, so
extra layer of cells form
...


Why do black-skinned people have
lighter colored palms and soles?
• Only the Stratum Basale has pigmentcontaining cells, but the stratum lucidum
contributes the color of protein, which is
an orange- tan color
...

The tan colored protein blocks the
underlying melanocytes from view
...

If the blisters are small (less
• 5 mm in diameter), then
than The epidermis they dies because it’s too
are known as vesicles; if they
far away from nutrients
...

mm in diameter), they are
termed bullae
...

Three major types:

1) BASAL CELL CARCINOMA
2) SQUAMOUS CELL CARCINOMA
3) MELANOMA

Conditions of the Skin
• Eczema
–Atopic dermatitis
–Contact dermatitis
• Seborrheic
dermatitis
• Psoriasis

Eczema
• Itchy red skin that comes and goes
...

• The most frequently occurring form of
eczema is ATOPIC DERMATITIS
...

• Can be triggered by changes in weather or
stress
...

• Treatment is lubricant creams daily and
steroid creams during outbreaks
...

• Poison ivy and oak, can
cause this type of
reaction
...

• People with a history of
allergies are more likely
to get contact dermatitis

Contact Dermatitis

Seborrheic dermatitis
• In Children, it is called “Cradle Cap”
• In Adults, it is called severe dandruff
• Caused by an allergy to the fungus that we
all have around our hair roots
...

• Treatment is shampoo with ketoconazole
(steroid) or coal tar
...


Seborrheic dermatitis

Psoriasis

• An autoimmune disease of the skin
...

• There are treatments, but no cure
...


Vitelligo
– An autoimmune disease of the skin
– Destroys melanocytes, especially in areas of
friction (eyelids, mouth, hands)
– Causes depigmentation
...

Has bumps)
• The papillary layer of the skin; LOOSE
connective tissue
...

• Surgeons make incisions on the body based
on the lines of cleavage of the skin formed
by the papillary layer of the DERMIS (Langer

Lines of Cleavage
• In the dermis, the bundles of collagen fibers are
mostly arranged in parallel rows
...

• The direction of the rows of collagen is known as
the lines of cleavage (Langer’s lines), and they
tend to run longitudinally in the limbs and
circumferentially in the neck and trunk

Lines of Cleavage

Dermis
RETICULAR LAYER
• DENSE IRREGULAR Connective
Tissue (although it tends to go in one
direction)
• Has lots of COLLAGEN and ELASTIN
• The DERMIS is where most of the
body’s collagen is found
...

• Remember, the epidermis is the
strongest layer of the SKIN, but the
reticular layer of the dermis is the

• The dermis is also the area where all the
glands of the body are located
...

• The blood vessels in the dermis are what gives a
pink color to Caucasian people
...
It’s
function is to maintain optimal blood levels
of calcium and phosphorus
...


HYPODERMIS:
• Varies tremendously in thickness: Shins =
thin; Buttocks = thick
...


Hypodermis Conditions
• Hypodermis is not connected to underlying tissue,
such as muscle
...
Fat is burned off
equally over entire body
...
More noticeable in
face than in hips
...
It
is NOT a special type of fat
...
It looks like wrinkled, “orange
peel” skin because the collagen fibers on top of it
bind it down like a net
...


LIPOSUCTION
• This is a surgical procedure where the patient
has fat sucked out of the hypodermis layer
...


Burns
• First degree burns
– Superficial partialthickness
– Involves just epidermis
– Get redness but no
blistering
– May peel in 1-3 days
– Get no scarring

• Second degree burns
– Deep partial-thickness
– Involves epidermis &
dermis
– Get redness & blistering
– Can get scarring
– Can get some fluid loss
– Get significant pain

• Third degree burns
– Full-thickness
– Involves all 3 layers &
may involve underlying
tissue
– Get no pain

• Rule of 9’s
– If burn 1st ,2nd , or 3rd &
involves more than 20%
---- needs medical
attention
– If burn 2nd or 3rd &
involves greater 20% =
serious
– If burn 2nd or 3rd &
involves greater 40% =
severe

• Complications
–
–
–
–
–

Fluid imbalance
Dehydration
Anemia
Infection
Excess scar formation

BURNS: Three types:
• FIRST DEGREE: Minor burn to the
epidermis; sunburn
• SECOND DEGREE: Dermis separates from
epidermis; blister
• THIRD DEGREE: Hypodermis is burned
...
60% burn = 60% chance
of dying
...
10a

Third Degree Burn

Why are deep burns so dangerous?
1) Infection
2) Dehydration: nothing to keep fluid in
body
...

• Skin grafts cause lots of scarring
...
A partial-skin-thickness burn
heals from the cells of the hair follicles,
sebaceous glands, and sweat glands as well as
from the cells at the edge of the burn
...

• To speed up healing and reduce the incidence
of contracture, a deep burn should be grafted
...

• In a split-thickness graft the greater part of the
epidermis, including the tips of the dermal
papillae, are removed from the donor site and
placed on the recipient site
...


• A full-thickness skin graft includes both the
epidermis and dermis and, to survive, requires
rapid establishment of a new circulation within it
at the recipient site
...

• In certain circumstances the full-thickness graft
is made in the form of a pedicle graft, in which a
flap of full-thickness skin is turned and stitched
in position at the recipient site, leaving the base
of the flap with its blood supply intact at the
donor site
...


DECUBITUS ULCERS
• Epidermis is destroyed, underlying tissue is
exposed
...
In you, it’s ok, because you’ll
be walking around again in a half hour
...

Ulcer forms, can get gangrene or go systemic
and die of infection
...


Decubitus Ulcers

SKIN COLOR; Caused by four
things:
1) MELANIN: (dark brown pigment)
...

2) CAROTENE: (a yellowish/orange pigment
found only in plants)
...

3) SKIN THICKNESS: thinner skin see blood
vessels, looks pinker
4) HEMOGLOBIN: The DERMIS contains the
blood vessels that give Caucasians the pink
color to the skin
...
But when you look at veins
through the adipose layer (the hypodermis),
they look blue
...
As it gets pushed upwards, it
appears green/yellow
...


CYANOSIS: Bluish color to skin
...

The oxygen is conserved for the vital
organs, so oxygen to skin and nails is shut
down
...

• Skin begins to sag because body makes less
elastin
...
Does it
bounce back, or ooze back?
• What can be done about wrinkles? Not much
...

• Creams don’t work
...

• That releases the tension, and relaxes the
skin line
...


COLLAGEN INJECTION
• Collagen is injected into hypodermis
...


MOISTURIZER CREAMS
• The secret ingredient of all moisturizers is
WATER
...
Although keratin is waterproof,
it swells when wet
...
Get the
same effect by soaking in the tub, and
that’s cheaper
...


HAIR

HAIR
• There are about 2 million hairs on the
body; 200,000 on the scalp
...
5c, d

Hair Loss
• Hair loss in men and women is due to the
presence of a male hormone (an
androgen)
...

• Women who have the baldness gene don’t
have as much of the male hormone; they
just get thinning of the amount of hair
...


Hair Loss
• Hereditary hair loss and premature greying
are some of the most common genetic
conditions
...

• An estimated 25% of women suffer from
female pattern baldness but, since their
hair loss is diffuse, it is not as easily
recognizable as the male form
...
SEBACEOUS GLANDS
1
...
Produce sebum (oil that coats the hair
and epidermis)
When you wash it away, the skin gets
dry
...


PIMPLES
• Some of the largest sebaceous glands are
associated with the smallest hairs (face)
...

• The sebum in the gland is exposed to oxygen
and turns black, called a blackhead
...

• In puberty, there is an increase in hormones,
and an increase in gland production leading to

• Pimple

Skin Infections
• The nail folds, hair follicles, and
sebaceous glands are common sites for
entrance into the underlying tissues of
pathogenic organisms such as
Staphylococcus aureus
...

Infection of the hair follicle and
sebaceous gland is responsible for the
common boil
...

• They are local infections that swell to a
size that is larger than pimples
...


Boil

• Most boils run their course within four to ten
days
...

• Once the boil drains, the area should be washed
with antibacterial soap and bandaged well
...


2
...

• The nails are made of keratin (no collagen or
calcium)
• At the nail root, there is rapid division of
keratocytes (cells that make keratin), and as
they die, the skin moves up and creates the nail
...


GLANDS
• ECCRINE (MEROCRINE) SWEAT
GLANDS
...
ECCRINE (MEROCRINE) SWEAT GLANDS
...

-Fun Facts: A pair of human feet contains 250,000
sweat glands
...

-Your body gives off enough heat in 30 minutes to
bring half a gallon of water to a boil
...
1

2
...

They produce a secretion to coat the hairs
...
These glands also
produce a type of protein called a hormone
known as PHEROMONES
...
If you put several
women in one room for months, their
menstrual cycles will all start to occur at the
same time
...

There is no conscious odor
...
Expensive perfumes
have pheromones
...


3
...
They secrete milk
...
In a woman who is not
lactating, the majority of tissue is adipose
...


4
...

– They keep the ear canal from drying
out
– They prevent insects from crawling in;
they don’t like walking on the wax

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