Transcript Integumentary Syst 2

1. To identify the components of the
integumentary system
2. To identify layers of skin and their function
3. To identify and determine the function of
the accessory structures
4. To identify common disorders and
treatments of the integumentary system
• Derives its name from the Latin word
“integumentum,” which means “to cover”
• Is the largest, heaviest organ in the body
• Is absolutely necessary for life
This is what your body would look like
without the integumentary system!
• Skin
– epidermis
– dermis
– hypodermis
• Accessory Structures
– hair
– nails
– exocrine glands
Skin = Integument = Cutaneous
Membrane
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7 Functions:
Protective covering
Regulates body temperature
Manufactures Vitamin D
Sensory function
Temporary storage of fat, glucose, water and
salts
Screens out harmful ultraviolet radiation
Absorbs certain drugs
STRUCTURE OF
THE SKIN
2 basic layers
Epidermis
• Outermost covering
• Epithelial cells
• Avascular
• Produced vitamin D
Dermis
• True skin
• Connective tissue
• Vascular
Take a look at your hands. What do you see
happening?
Although you are not able to see it, you epidermis is
constantly working around the clock. The bottom
layer of the epidermis is hard at work synthesizing
new skin cells. When the new cells are developed,
they begin making their way toward the outer layer of
the epidermis. A continuous pattern develops. New
cells are constantly made and help push the dead cells
upward. As old cells die near the top, they rise to the
surface of your skin. So, what you really see when you
look at your skin are dead skin cells.
EPIDERMIS
2 (of 3) epidermal layers are:
Stratum corneum
Stratum germinativum
STRATUM CORNEUM
• Outermost layer
• In cells, cytoplasm replaced by KERATIN – making them
waterproof.
• Flat and scale-like cells that flake off
• First line of defense against surface bacteria
• Thickest on palms of hands, soles of feet
STRATUM GERMINATIVUM
• Innermost layer
• Reproductive layer – cells form and push their way up, become
keratinized, and replace the top layer
• Contains MELANOCYTES – cells that contain a pigment =
MELANIN
Melanin
 Black, brown, or has a yellow
tint – depending on racial
origin
 Protects the body against UV
radiation
 Absorbs UV light before
damage occurs to cells’ DNA
 The more melanin, the darker
the skin
 Caucasians don’t have much
melanin in their melanocytes.
 Freckles = patches of melanin
 Albinism = no melanin
PAPILLAE
• Ridges in stratum germinativum
that arise from dermis
• Create permanent ridges in
fingers, palms and soles of feet
• These “friction ridges” help with
grip
• Cause “fingerprints”
DERMIS
• Is the second thicker layer of skin
• Contains the accessory structures
– Hair
– Sweat glands
– Oil glands
• Contains blood vessels, which
supply nutrients and oxygen to the
cells
• Contains sensory receptors
(nerves) for:
– touch
– pressure
– hot and cold
– pain
Nerve Receptors in Dermis
Sensory nerves – heat, cold,
touch, pain and pressure
Touch receptors - close to the
surface
Pressure receptors - are deeper
• Distributed over the entire
skin surface
• Large numbers under the
arms, palms of hands, soles
of feet and forehead
• Duct extends to form a pore
in the skin, perspiration
excreted through the pores
• May be activated by heat,
pain, fever and nervousness
• Average fluid loss is 500 ml
per day
• Perspiration is 99% water
• Produce a mixture of lipids
and proteins called sebum
• Function to prevent drying
of skin and hair
• Are located primarily on the
scalp, face and upper
portion of the body
• Increase in size and
produce a greater amount
of sebum in coordination
with increased hormone
levels
• Is also called the
subcutaneous layer
• Is the innermost
layer of skin
• Is composed
primarily of fat
• Acts as a shock
absorber
• Anchors skin to
underlying muscle
• Origin of hair follicles
– follicles are tiny tubes in
which body hair grows out
of
– follicles are found all over
your body, except the lips,
palms of the hands and
soles of the feet
So why do my fingers wrinkle when I
take a bath?
Your skin does have a waterproof coating of sebum
and sweat. However, when you are exposed to
water for long periods of time, this waterproof
coating washes away. Once this coating is washed
away, your skin can absorb water. When your skin
absorbs water it gets soggy and wrinkly. After you
dry off, your skin will begin to replenish the layer
of sebum and sweat.
Appendages of the Skin
HAIR
• Fibers, non-living protein
structures
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Amount & type are species and
environment dependant
• Has capillaries and nerves
attached to follicle, which
provide nutrients and sensory
information
• Outer layer = CORTEX
• Inner layer = MEDULLA
• Part under the skin = ROOT
• Part outside the skin = SHAFT
FOLLICLE = “pocket” in epidermis,
hair inside
PAPILLA = tuft of tissue in root,
contains capillaries
ARRECTOR PILI MUSCLE = smooth
muscle attached to follicle.
Q: How does this muscle cause
goose bumps?
A: When they contract, they pull the hair
into an upright position, causing skin
dimples (goose bumps). The nervous
system regulates these muscles; cold
temperatures or fright can activate them.
What makes my hair shiny?
At the dermis layer, each follicle has its own
sebaceous gland. The sebaceous gland releases
sebum onto the hair. Sebum lightly coats your
hair, making it shiny and slightly waterproof.
Alopecia – absence of hair
Nail
• Develop from the epidermis
• Formed in the nail bed or MATRIX
• Epidermal cells fused together and
fill with keratin
• Appear pink because their
translucency reveals the vascular
tissue beneath.
• They aid in grasping, scratching, and
protecting fingers and toes.
Components:
– The lunula is the white halfmoon at the nail base.
– The body and free edge
overhangs the end
– The nail rests on the thick
layer of epithelial skin
called the nail bed.
• The hyponychium is the
epithelium of the nail bed
– The root is hidden under
skin
• Under the root lies the
matrix (thick layer of skin).
– Eponychium (thin layer of
epithelium) covers the nail
during development; in the
adult, it remains at the nail
base only and is called the
cuticle.
Skin and
Microorganisms
• Intact skin = best protection against pathogens,
toxins and water loss
• Skin generally too dry for microbial growth – they do
grow in moist areas
• Most skin bacteria associated with hair follicles or
sweat glands
• Underarm perspiration odor caused by bacteria and
perspiration
The best way to prevent the
spread of disease is by
hand washing.
If the body is too hot
and needs to
release heat:
• A signal from the
hypothalamus (part of
the brain) is sent to the
skin and warm blood is
brought closer to the
surface of the skin
• Sweat glands begin
producing lots of sweat
to release into the air,
cooling the body
When the body is
cold and needs to
conserve heat:
• The brain senses cold
body temperatures
• Blood vessels constrict
to keep warm blood
away from the surface
of skin
• Pilomotor reflex occurs–
formation of “goose
bumps”
☻An adult’s skin weighs about 5-10 pounds
☻If your skin was spread out like a blanket,
it would measure about 20 square feet
☻Each minute we loose 30,000 – 40,000
skin cells off the surface of our skin
☻There are more than 100,000 hair follicles
on your head
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ACNE
ATHLETE’S FOOT
DERMATITIS
ECZEMA
WARTS (VERRUCAE)
GENITAL HERPES
IMPETIGO
PSORIASIS
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RINGWORM
URTICARIA / HIVES
BOILS (CARBUNCLES)
SHINGLES (Herpes Zoster)
HERPES SIMPLEX 1
GENITAL HERPES
SCABIES
SKIN CANCER
– BASAL & SQUAMOUS CELL
CARCINOMA, MALIGNANT
MELANOMA
ACNE
• Disorder of the
sebaceous glands
• Sebum plugs pores and
area fills with leukocytes
• Blackheads, cysts,
pimples, and scarring
Boils
• a.k.a.
Carbuncles
• Painful,
bacterial
infection
Athelete’s Foot
• Contagious fungal
infectious
• Usually contracted in
public baths and
showers
• Rx – antifungal
agents
Dermatitis
• Non-specific skin inflammation
• Rash – reaction to soap, plants, etc.
• Skin blotches – caused by stress
Eczema
• Acute or chronic inflammatory skin
disease
• Skin dry, red, itchy and scaly
• Rx – remove cause, hydrocortisone to
help alleviate symptoms
Herpes
• Genital herpes
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Viral blister in genital area
Spread through sexual contact
Periods of remission & exacerbation
Rx: Acyclovir
Can be passed to newborn during delivery
• Herpes Simplex I
– Virus
– Fever blister or coldsore
• Shingles (zoster)
– Viral infection of nerve endings
– On chest or abdomen, accompanied by severe pain
Impetigo
• Acute, inflammation and contagious
• Seen in babies and young children
• Caused by staphylococcus or
streptococcus
• Vesicles that rupture and develop distinct
yellow crusts
Psoriasis
• Chronic
inflammatory
skin disease
• Dry reddish
patches
covered with
silvery-white
scales
Ringworm
• Contagious fungal infection
• Raised, itchy, circular patches with crusts
Scabies
• Communicable
• Severe itching
• Mite burrows in skin, lays eggs, eggs
hatch
Tanning
• Sunlight stimulates melanocytes to make
more melanin
• Tanning produced by UV rays.
• Prolonged exposure may lead to skin
cancer!
SKIN CANCER
Associated with exposure to sun (UV rays)
***Most common type of cancer in people***
• BASAL CELL CARCINOMA
– Most common, least malignant
– Usually on face
– Rx: surgery or radiation
• SQUAMOUS CELL CARCINOMA
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Mostly scalp and lower lip
Grows rapidly and metastasizes to lymph nodes
Rx: surgery or radiation
Prognosis good with early diagnosis
SKIN CANCER (cont)
• MALIGNANT MELANOMA
– Occurs in melanocytes
– Metastasizes to other areas quickly
– Appears as brown or black irregular patch that
occurs suddenly
– A change in an existing wart or mole
– RX: surgical removal of melanoma and
surrounding area & chemotherapy
Skin Lesions
• Pustule – acne
• Ulcer – venous stasis ulcer superficial or
decubitus
• Tumor – benign epidermal tumor, basal cell
carcinoma
• Vesicle – chicken pox, herpes simplex
Other Terms:
Excoriation – abrasion
Pruritis - Itching
BURNS
First Degree
• Superficial
• Skin red and dry
• Involves only
epidermis
• Rx – cold water
• Healing within one
week
Second Degree
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Epidermis and dermis
Pain, swelling, redness and blistering
Skin may be exposed to infection
Rx – pain medication, dry sterile dressing
Healing within 2 weeks
Third Degree
• Epidermis, dermis
and subcutaneous
layers
• Symptoms – loss
of skin, blackened
skin
• May be life
threatening
RULE OF NINES
Measures percent of body burned. Body divided into 11 area,
each is 9% of body surface.