1. Dermis & Accessory Structures (Hair, Glands, Nails)

2. Dermis Beneath epidermis
The location for blood vessels, nerves, glands, hair follicles, and arrector pili (smooth muscle; contractions produce “goose bumps”)

3. Fig. 5.2
Papillae = nipples

4. Dermis - Structure Papillary region - upper layer - 20%
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Dermis - Structure
Papillary region - upper layer - 20%
Areolar connective tissue
Reticular region - 80%
Underneath the papillary layer
Dense irregular connective tissue
Fibers tolerate limited stretching; “stretch marks” can appear
(not clear boundary between the two layers)

5. Hair Functions: Protection Insulation Sensation
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Hair
Functions:
Protection
Insulation
Sensation
Secondary sexual characteristic to attract mates
Rate of growth & replacement affected by:
heredity, diet, illness, fever, blood loss, surgery, drugs, chemotherapy, etc.

6. Hair Cont. Hair Follicle – site of hair origin Hair:
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Hair Follicle – site of hair origin
Hair:
Shaft (above skin surface)
Root & bulb (underneath skin surface)
Bulb contains matrix – dividing layer; builds hair
Hair is made out of keratin
brown, black - melanin deposited from the matrix of the bulb into the shaft
red, blond - variants of melanin with iron, sulfur in the molecule
grey - some loss of melanocytes reduces melanin deposition

8. Nails tightly packed, hard, keratinized cells
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Nails
tightly packed, hard, keratinized cells
nail matrix - site of nail growth; under root of nail
1 mm/week in fingers; slower in toes
Nail matrix - transforms normal skin cells into nail cells which push forward

10. Sebaceous (Oil) Glands
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Sebaceous (Oil) Glands
connected to hair follicles in the dermis
secrete sebum (oil)
keeps hair from drying
prevents water evaporation from skin
keeps skin soft, supple
inhibits growth of many bacteria
Sebum = fats, cholesterol, proteins, inorganic salts
busy at puberty

11. Sudoriferous (Sweat) Glands
Eccrine (merocrine) glands:
In the skin that covers most parts of our bodies
Produce a thin, watery liquid that contains salt and small amounts of other bodily wastes
Help cool the body through the process of evaporation
Apocrine glands:
In the skin of the armpits, around nipples, and in the groin
Produce a thicker salty and acidic solution
Produce “body odor” (in contact with bacteria)
Become active when a person reaches puberty
Secrete more during emotional stress & sexual arousal

12. Apocrine & Eccrine Sweat Glands

13. Other Specialized Integumentary Glands
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Other Specialized Integumentary Glands
Ceruminous glands – together with oil glands produce ear wax
protect against foreign particles & small insects

14. Burns