Transcript Chapter 10 Integumentary System

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 Called
a membrane because it covers
the body
 Called an organ because it contains several
kinds of tissues
 Called a system because it has organs
and other parts that work together for
a particular function
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 Epidermis—outermost
layer
 Dermis—“true
skin”
 Subcutaneous fascia or hypodermis—
the innermost layer
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 Epidermis




(cuticle)
Outermost layer of the skin
Composed of a surface of dead cells with an
underlying layer of living cells
Contains sebaceous and sudoriferous glands as
well as hair follicles
Melanocytes (produces melanin) are located in
the epidermis

Melanin: pigment that gives skin its color
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 Dermis


(corium)
Called the “true” skin
Contains the blood vessels and nerves

Each inch of skin contains many blood vessels
 Subcutaneous


Innermost layer
Contains adipose, which cushions and insulates
the body’s organs
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 Skin
has hair in all areas except the soles of
the feet and palms of the hands
 Hair blocks foreign particles from entering
the body through structures such as the nose
and eyes
 The visible portion is called the shaft
 The hair follicle is the root with its covering
 Hair- external insulation
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 Three

Sebaceous glands (oil)




types of glands in the skin:
Located everywhere except palms of hands and soles
of feet
Sebum (oil) causes the skin to be soft and waterproof
Coat the hair with oil
Sudoriferous glands (sweat)

Help regulate the body temperature and excrete body
wastes
cool the body
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
Ceruminous glands


Located in the auditory canal of the ear
Secrete wax that helps protect the ear from infection
and prevents entry of foreign bodies
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 Function
is to protect fingers and toes from
injury- protective covering
 Formed from dead, keratinized epidermal
cells
 Root is covered by skin at the area of
attachment to finger or toe

Lunula is the crescent-shaped white area near
the root
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 Dermatology



Study of skin
Dermatitis is inflammation of the skin
Skin lesions can be seen with visual inspection



Size, shape, texture, and color often reveal cause
Biopsy is used to identify the causative organism
Fingerprints and toe prints are unique to each
person
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 Acne

Caused by increased secretion of oil related to
increased hormones during puberty

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Primarily affects the face, chest, and back
Digests sebum
Attracts neutrophils
Neutrophil digestive enzymes cause lesions, “pus
pockets”
Oil-based cosmetics worsen disease
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Acne Treatment
 Benzoyl
peroxide dries plugged follicles, kills
microbes
 Tetracycline (antibiotic)
 Accutane – inhibits sebum formation
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More Disorder of the Skin
 Albinism

Inherited disorder in which melanin is not
produced
 Alopecia

Baldness
 Athlete’s

foot
Contagious fungal infection of the foot
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 Dandruff
 White flakes
 Eczema
 Group of
reactions

disorders caused by allergic or irritant
Psoriasis


of dead skin cells from the scalp
Chronic skin disorder in which too many epidermal cells are
produced
Rashes

May result from viral infection, especially in children
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 Skin
cancer


 Skin

Sun and skin cancer
 Damage by ultraviolet rays
 Types of skin cancer
Three forms are basal, squamous, and melanoma
lesions
Differ in texture, color, location, and rate of growth
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 Skin


and hair care
Skin care products include soap, astringents, and
cosmetics
Ways to remove hair include wax, depilatory
creams, and electrolysis

Tattooing (permanent makeup)
 Risk of infections, allergic reaction, and
complications during MRI
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House dust is mainly skin flakes!
 If you laid out all your skin on a flat surface, it would
have an area of about 2 square meters.
 Skin weighs about 2.5 kilograms - the largest organ in
the body.
 What hurts if you pull it, but doesn't hurt if you cut
it? Your hair, of course!
 Skin is elastic - it springs back into shape when
stretched. Some medicines (estrogen, nicotine) can
pass through the skin, but others cannot (insulin).
Why is that? Because only fat-soluble substances can
enter the skin, not water-soluble ones.
 Your hair stands on end and you develop 'goose
bumps' because there are tiny muscles attached to
the hair follicles and they contract when you are
frightened or cold.

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