Integumentary System Topics To Study – ANSWER KEY
 ABCD Rule and how to identify melanoma
 Importance of Using Sunscreen
Sunscreen
Since the number one risk factor for skin cancer is sun exposure, the use of sunscreen is the best
Prevention.
UV-A radiation will not cause sunburns, but can still
increase the risk of skin cancer. Only broad-spectrum sunscreens actually block both UV-A and
UV-B radiation.
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Diagram (epidermis, dermis, hypodermis, hair follicle, arrector pili, sudoriferous gland, sebaceous
gland)
 Layers and characteristics of the epidermis
 Epidermis—outer layer
Stratified squamous epithelium
Can become keratinized (hardened by keratin) to prevent water loss
Avascular (no blood supply of its own)
Most cells are keratinocytes (cells that produce keratin – a fibrous protein that makes the epidermis tough)
 Dermis
Dense connective tissue
 Subcutaneous tissue (hypodermis) is deep to dermis
Not technically part of the skin
Anchors skin to underlying organs
Composed mostly of adipose tissue
Layers of the Epidermis and what are they:
Summary of layers from deepest to most superficial
 Stratum basale
 Stratum spinosum
 Stratum granulosum
 Stratum lucidum (thick, hairless skin only)
 Stratum corneum
 Melanin/melanocytes
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Pigment (melanin) produced by melanocytes
Melanocytes are mostly in the stratum basale
Color is yellow to brown to black
Amount of melanin produced depends upon genetics and exposure to sunlight
 Functions of skin
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Protects deeper tissues from:
o Mechanical damage (bumps)
o Chemical damage (acids and bases)
o Bacterial damage
o Ultraviolet radiation (sunlight)
o Thermal damage (heat or cold)
o Desiccation (drying out)
Aids in body heat loss or heat retention as controlled by the nervous system
Aids in excretion of urea and uric acid
Synthesizes vitamin D
 Layers of hair
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Hair anatomy
o Central medulla
o Cortex surrounds medulla
o Cuticle on outside of cortex
 Most heavily keratinized
 Nails
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Free edge
Body: visible attached
portion
Root: embedded in
skin
Cuticle: proximal nail
fold that projects onto
the nail body
 Causes of abnormal skin color
 Redness (erythema)—due to embarrassment, inflammation, hypertension, fever, allergy, or conditions
like rosacea
 Pallor (blanching)—due to emotional stress such as fear, anemia, low blood pressure, impaired blood
flow to an area
 Jaundice (yellowing)—liver disorder
 Bruises—hematomas
 Burns (classify and explain)
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First-degree burns
o Only epidermis is damaged
o Skin is red and swollen
Second-degree burns
o Epidermis and upper dermis
are damaged
o Skin is red with blisters
Third-degree burns
o Destroys entire skin layer;
burned area is painless
o Burn is gray-white or black