Download Chapter 14 Notes 2013

Integumentary System (Skin)
 Includes your skin, hair, nails, and sweat glands
Functions of your skin:
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Watertight covering
It helps protect internal tissue and organs
Body’s first line of defense against invading pathogens.
Protection against Ultraviolet rays.
Major sense organ, serving as a means of communication
with your outside environment.
Epidermis: The outer, thinner layer of skin that is
composed of living and dead cells.
 Most cells of the epidermis contain a protein called
Keratin.
 Keratin helps waterproof and protect the cells.
 There are many layers of cells in the epidermis
 Dead cells make up the outermost level.
 Cells shed off when clothing rubs your skin or when you
wash.
 Through this shedding, your outer skin is replaced about
once a month.
 Old cells are replaced by new cells
 In the inner level of the epidermis the new cells contain
melanin.
Melanin: Gives the skin, hair, and iris of the eyes their
color.
Dermis: Is the thicker layer of the skin beneath the
epidermis that is made up of connective tissue and contains
blood vessels and nerves.
 The dermis has protein fibers that give the skin its
elasticity, or spongy, flexible quality.
 Nerve cells in the dermis act as receptors, which are
stimulated by changes in the outside environment.
 These receptors enable you to feel sensations such as
pressure, pain, hot, and cold
Sebaceous glands: Structure within the skin that produces
an oily secretion called sebum.
Sebum: Oily secretion that helps keeps the skin and hair
from drying out.
Sweat glands: Secrete perspiration through ducts to pores
on the surface of the skin.
 Involved in temperature regulation
 Produce perspiration on the surface of the skin
 Body heat is lost as the sweat evaporates
Hypodermis (Subcutaneous Layer):
 Attaches your skin to bone and muscle.
 Blood vessels and nerves that supply your skin pass
through the hypodermis.
 This layer is made up of fatty tissue and serves as the
body’s natural insulations against heat and cold.
Skin and the Sun:
 When skin is exposed to UV rays, whether from the sun, a
tanning booth, or another source, melanin production is
increased
 Fair-skinned people, whose skin has little melanin, and
thus little natural protection from UV radiation, burn in the
sun.
 Skin will become wrinkled or hard and leathery with
repeated exposure to UV radiation.
Protection:
 Always wear sunscreen, with Sun Protection Factor (SPF)
45 or better, on exposed areas of skin.
 Wear protective clothing.
Body Piercing and Tattooing:
 Both procedures result in the physical barrier of the skin
being broken.
 Possibility of bacteria or viruses entering the body
increases.
 New bacteria can be introduced through nonsterile needles.
 Transfer of bloodborne pathogens
o Hepatitis B
o Hepatitis C
o HIV
 Tattoos can be removed by using a laser procedure, but
can cause skin to discolor and infection could leave scars.
Skin Problems:
Acne: Caused when pores in the skin get clogged and the
sebum produced cannot reach the skin’s surface.
Warts: Virus that infects the surface layers of the skin
commonly found on hands, feet, and face.
Vitiligo: Skin condition in
which patches of skin have
lost all pigment.
Boils: Form when hair
follicles become infected with
bacteria that are normally found on the surface of the skin.
Moles: Spots that contain extra melanin.
 Most moles are harmless
 Moles may develop into Melanoma.
Melanoma: The most serious form of skin cancer.
 A B C D E’s of Melanoma:
o Asymmetry: Imaginary line
drawn through the center of
the mole does not produce
matching halves.
o Border irregularity:
Noncancerous moles have
smooth edges. Suspect
moles often have irregular
edges.
o Color: Look for moles that
are intensely black, possibly
with a bluish tint, uneven
color.
o Diameter: Check for moles
that are wider across than a
pea.
o Evolving: Moles should not
grow.
Preventions:
 Every morning and evening, wash your face with soap and
water.
 Eat a well-balanced diet with vitamin “A”
 Keep your hands away from your face.
Hair Follicle: Structure that surrounds the root of hair.
 100,000 to 200,000 hairs on your head lone.
Hair Problems:
 Dandruff
o Flaking of the outer layer of dead skin cells covering
the skull.
 Head lice
o Insects that attach themselves to the human hair and
skin and feed off blood.
Prevention:
 Brushing your hair helps keep dirt from building up and
helps evenly distribute the natural hair oils.
 Limit the use of treatments such as permanents, dyes, or
bleach.
 Don’t over brush your hair.
 Washing your hair regularly is necessary for healthy hair.
Nail Problems:
 Hangnails
 Ingrown toenails
Prevention:
 Keep nails clean and evenly trimmed
 Keep cuticles pushed back and clip hangnails with a nail
clipper.
 Never bite your nails.
 Cut toenails straight across
 Fingernails should be slightly rounded