Download Integumentary System

Integumentary System
Skin = Integument
Skin
Skin has 7 functions
 Protective Covering.
 Regulates body temperature.
 Manufactures Vitamin D.
 Sensory Function (touch, pressure, etc.)
 Temporary storage of fat, glucose, water and
salts.
 Screens out harmful ultraviolet radiation.
 Absorbs certain drugs.
Layers of Skin
 2 basic layers (Epidermis and Dermis)
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Epidermis
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Outermost covering
Epithelial cells
Avascular
Stratum Corneum = outermost layer of epidermis.
Stratum Germinativum = innermost layer of
epidermis
http://www.nku.edu/~dempseyd/SKIN.htm
Stratum Corneum
 Outermost layer of
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epidermis
Cytoplasm inside cells
is replaced with keratin,
keratin makes the cells
waterproof.
Cells are flat and flake
off.
First line of defense
against surface
bacteria.
Thick on hands & feet.
Stratum Germinativum
 Innermost epidermal layer.
 Reproductive layer = new cells grow and
push their way up, then become keratinized,
and replace the top layer which flakes off.
 Contains melanocytes = cells that contain
pigment (melanin).
 Ridges in stratum germinativum arise from
the dermis, these ridges are called Papillae.
Melanin
 Pigment color depends on
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racial origin.
The more melanin, the
darker the skin.
Freckles = patches of
melanin.
Albinism = no melanin.
Sunlight stimulates
melanocytes to make more
melanin.
Most skin cancer caused by
sun (UV) exposure.
Papillae
 Ridges that arise from
the dermis create ridges
in the epidermis =
Papillae.
 Permanent ridges are
present on fingers,
palms of the hands, and
soles of the feet.
 Finger prints = friction
ridges = grip
Dermis
 Thick
 True skin
 Connective tissue
 Vascular
 Contains :
 Blood vessels, nerve
endings (sensory),
muscles, hair follicles,
oil and sweat glands,
and fat cells (adipose
tissue).
Subcutaneous Layer
 Lies under the dermis
 Not really part of the
Integumentary system.
 Made up of loose
connective tissue.
 Contains half of the
body’s stored fat.
Appendages of the Skin
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Hair
Outer layer = Cortex
Inner layer = Medulla
Part under the skin =
Root
 Part outside the skin =
Shaft (part we see)
 Pocket that holds hair =
Follicle
 Tissue in root that
contains capillaries =
Papilla
Alopecia
 Baldness.
 Normal hair replaced
with fine almost
transparent hair.
Appendages of Skin
 Nails
 Nail is formed in the nail bed or MATRIX.
 Epidermal cells fuse together and fill with KERATIN.
Sweat Glands (Sudoriferous Glands)
 Perspiration is 99% water.
 All over skins surface but
large #s are present under the
arms, palms of the hands,
soles of the feet, and
forehead.
 Duct extends from the dermis
to the epidermis and forms a
pore in the skin.
 May be activated by heat,
pain, fever, and nervousness.
 Average fluid loss is 500ml
per day.
Oil Glands (Sebaceous Glands)
 Secrete oil (Sebum).
 Protects and lubricates
the skin and hair.
 Glands usually located
with a hair follicle.
Arrector Pili Muscle
 Smooth muscle attached to hair follicle
 Arrector Pili muscle pulls on follicle causing hair to move.
 Bumps or Goose Bumps are seen on the skin.
 Purpose is to trap a layer of warm air around the body.
Skin and Microorganisms
 Intact skin = best protection against
pathogens, toxins, and water loss.
 Skin generally too dry for microbial growth,
except for moist places.
 Most skin bacteria associated with hair
follicles or sudoriferous glands.
 Perspiration odor caused by bacteria.
 The best way to prevent the spread of
disease is by hand washing.
Handwashing
 http://www.scrubclub.org/site/meet.aspx
 http://www.cdc.gov/CDCTV/HandsTogether/
Disorders of the Skin
 Acne
 Common, sometimes chronic, disorder of sebaceous glands.
 Sebum (oil) plugs pore, sometimes bacteria grows, then area
fills with leukocytes (WBC) in an effort to clear plug and/or
bacteria.
Athlete’s Foot
 Contagious fungal
infection.
 Usually contracted in
public baths, and
showers.
 Need antifungal
medication to cure
athlete’s foot.
Dermatitis
 Non-Specific inflammation of the skin.
 Rash – reaction to soap, lotions, plants etc.
 Blotches – can be caused by emotional stress.
Genital Herpes
 Viral = virus causes genital
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herpes.
Blisters appear in genital
area.
Periods of remission and
exacerbation.
Spread through sexual
contact.
Can be passed to newborn
during vaginal birth. May
need C-Section.
Acyclovir may help decrease
outbreaks and length of each
outbreak.
Video
Skin Cancer
 Most common type of cancer.
 Main cause is exposure to sun (UV rays).
 Example: Basal Cell Carcinoma (below).
 Video
Malignant Melanoma
 Occurs in melanocytes.
 Appears as a brown, or
black, irregular patch.
 A change in an existing
wart or mole may
indicate melanoma.
 Metastasizes to other
areas quickly.
 Must surgically remove
area & do
chemotherapy.
Melanoma
Burns
 Caused by radiation,
sun, boiling water,
chemicals, fire, or
electricity.
 Rule of Nines =
measures % of body
burned. Body is divided
into 11 areas, and each
is 9% of body surface.
First Degree Burns
 Superficial.
 Skin red and dry.
 Involves only epidermis.
 Apply cold water,
wound should heal
within one week.
Second Degree Burn
 Involves epidermis and
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dermis.
Pain, swelling, redness,
and blistering
May be exposed to
infection due to broken
skin.
Give pain medication,
apply a dry sterile
dressing.
Heals within 2 weeks.
Third Degree Burn
 Epidermis, dermis, and
subcutaneous layers
involved.
 Blackened skin, areas
of skin may be totally
gone.
 May be life threatening.
 Need to seek medical
attention.
 The End
 Integumentary System
 Allied Health I