Download The Integumentary System - Southgate Community School District

The Integumentary System
Section 32.3
Functions
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Protection
Temperature Regulation
Excretion
Information Gathering
Vitamin D Production
Structure: Skin
• Epidermis
– Outer layer of skin
– Two layers
• Top layer=dead cells
• Inner layer=living cells &
stem cells.
– Melanocytes
• Dermis
– Contains
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collagen
blood vessels
nerve endings
sensory receptors
hair follicles
smooth muscle
sweat/sebaceous glands
Structure: Hair
• Made of keratin
• Protects against UV rays, cold temps, and
dirt/pathogens from entering nose/eyes/ears.
• Produced in hair follicles
Structure: Nails
• Made of keratin
• Grow from nail root
– Cells divide and are filled with keratin
• This produces a tough, plate-like nail
• Grow at 3mm per month
Skin Problems
• Acne
– When sebum/dead cells plug hair follicles
– Bacteria trapped in plug
– 85% people experience
Skin Problems
• Hives
– Red welts, signify an allergic reaction
– Histamines released, cause swelling, blood vessel
widening.
– Fluid oozes into surrounding tissues.
Skin Problems
• Cancer
– Excessive exposure to UV radiation.
– 60,000 people in USA get it each year, 8000 die.
– Protect yourself from both UV-A and UV-B rays!
Skin Cancer
• Basal cell carcinoma
• Squamous cell carcinoma
• Melanoma