1. Skin Structure Epidermis – outer layer Stratified squamous epithelium
Often keratinized (hardened by keratin)
Dermis
Dense connective tissue
Slide 4.10a
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2. Skin Structure Deep to dermis is the hypodermis Not part of the skin
Anchors skin to underlying organs
Composed mostly of adipose tissue
Slide 4.10b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

3. Layer of Epidermis Stratum basale Stratum spinosum Stratum granulosum
Cells undergoing mitosis
Lies next to dermis
Stratum spinosum
Stratum granulosum
Slide 4.11a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

4. Layer of Epidermis Stratum lucidum Stratum corneum
Occurs only in thick skin
Stratum corneum
Shingle-like dead cells
Slide 4.11b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

5. Melanin Pigment (melanin) produced by melanocytes
Color is yellow to brown to black
Melanocytes are mostly in the stratum basale
Amount of melanin produced depends upon genetic and exposure to sunlight
Slide 4.12
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

6. Dermis Two layers Papillary layer Projections called dermal papillae
Pain receptors (free nerve endings)
Capillary loops
Reticular layer
Blood vessels
Glands
Nerve receptors (Pacinian Corpuscle- pressure, Meissner Corpusle- touch)
Slide 4.13a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

7. Skin Structure Figure 4.4 Slide 4.13b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

8. Appendages of the Skin Sebaceous glands Produce oil Lubricant for skin
Kills bacteria
Most with ducts that empty into hair follicles
Glands are activated at puberty
Slide 4.15
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings