1. Skin and the Integumentary System
Section 32:1

2. The Structure of the Skin
Skin is a multilayered organ that covers and protects the body
Largest system of body – 16% of body weight
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The Integumentary System

3. The Structure of the Skin
The epidermis
The outer superficial layer of skin is the epidermis.
The outer layers of epidermal cells contain keratin, which waterproofs
and protects the cells
and tissues that lie
underneath.
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The Integumentary System

4. The Structure of the Skin
The epidermis
Some cells in the inner layer of the epidermis provide protection from harmful ultraviolet radiation by making a pigment called melanin.
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The Integumentary System

5. The Structure of the Skin
The dermis
Directly beneath the epidermis.
The dermis consists of connective tissue, nerve cells, muscle fibers, sweat glands, oil glands, and hair follicles.
Below the dermis layer is the subcutaneous layer
a layer of connective tissue
stores fat & helps the body retain heat.
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The Integumentary System

6. The Structure of the Skin
Hair and nails
Both hair and nails contain keratin and develop from epithelial cells.
Hair cells grow out of narrow cavities in the dermis called hair follicles.
Hair follicles usually have sebaceous glands associated with them that lubricate the skin and hair.
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The Integumentary System

7. Functions of the Integumentary System
Vitamin production
Produces Vitamin D
Increases the absorption of calcium
Protection
First line of defense
Keeps skin from drying out
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The Integumentary System

8. Functions of the Integumentary System
Temperature regulation
Blood vessels in skin expand and contract depending on temperature
Cold  blood vessels narrow
Keep warm blood away from surface
Hot  blood vessels expand
Bring warm blood to surface
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The Integumentary System

9. Functions of the Integumentary System
Sensation and senses
Send signals through the spinal cord to the brain
Nerve receptors are not evenly spaced throughout the body
Furthest apart: middle of back
Closest together: hands, lips, face, tongue and feet
Increases the absorption of calcium
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The Integumentary System

10. Ridges and Ducts
Figure 5–4

11. Functions of the Integumentary System
Health Warnings
texture
temperature
color
Yellowish color - Liver
Dark brown spots - cancer
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The Integumentary System

12. Protection and Care of Skin
Sunlight
UVB rays cause sunburns
Sunscreen spf 15+
Protects against 93% UVB rays
Prevent sunburn, wrinkles and skin cancer
UVA rays cause wrinkling and sunspots
Penetrate deeper
Both types of rays can lead to cancer
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The Integumentary System

16. Protection and Care of Skin
Cuts
Gently wash cut with warm water and soap
Apply antibiotic
Cover until healed shut
1-2 days
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The Integumentary System

17. Protection and Care of Skin
Burns
Classified by severity
Apply a burn cream
Silvadine
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The Integumentary System

18. Degrees of Burn Injuries
Partial-thickness burns
Full-thickness burns
(a) First degree
(b) Second degree
(c) Third degree

19. Rule Of Nines
6-17

20. The Skin Gun National Geographic

21. Protection and Care of Skin
Insect Bites & Rashes
Avoid scratching
Use ointment to reduce itching
Lotions may have a burning sensation
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The Integumentary System

23. Protection and Care of Skin
Washing
Use warm water and mild soap
Strong soaps may remove oil from skin
Moisturizers help skin stay moist
Apply lotion after shower/bath
Skin sill be
Softer
Smoother
More elastic
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The Integumentary System

25. Life Span Changes
Scaly Skin Age Spots Dermis Becomes Reduced Loss of Fat Wrinkles Sagging Sebaceous Glands Secrete Less Oil Melanin Production Slows Hair Thins Number of Hair Follicles Decrease Impaired Nail Growth Sensory Receptors Decline Inability to Control Body Temperature Less Vitamin D Production
6-18

26. Clinical Application Acne Vulgaris 6-19 Most Common Skin Disorder
Sebum And Epithelial Cells Clog Glands
Produces Whiteheads And Blackheads (Comedones)
Anaerobic Bacteria Trigger Inflammation (Pimple)
Largely Hormonally Induced
Androgens Stimulate Sebum Production
Treatments Include Antibiotics, Topical Creams, Birth Control Pills
6-19

27. Lines of Cleavage Collagen and elastic fibers in the dermis:
are arranged in parallel bundles
resist force in a specific direction

28. Clinical Importance Lines of cleavage establish important patterns:
a parallel cut remains shut, heals well
a cut across (right angle) pulls open and scars

29. Lines of Cleavage
Figure 5–7