1. By: Madison Lipscomb, Shae Eggert, McKenna Hagan, Malik McFarlane
Skin Anatomy
By: Madison Lipscomb, Shae Eggert, McKenna Hagan, Malik McFarlane

2. Layers of the Skin

3. Epidermis
Definition: The upper or outer layer of the two main layers of cells that make up the skin.
Provides a waterproof barrier, and creates skin tone Serves as the protective layer, i.e. a parka that you would wear in the winter to protect against the col., The inside is lined with soft fleece, providing a layer of warmth. But the outside is made of a strong waterproof material that lets nothing through. It is a similar situation with our own epidermis.
The cellular structure of the epidermis also forms a highly effective barrier against germs.
In addition, cells of the epidermis have the miraculous ability to regenerate, or grow back, unlike many other cells in the body.
Epithelial Cells, reproduce

4. Dermis
Reticular Dermis: the deeper and thicker layer of the dermis, which lies above the subcutaneous layer of the skin. It contains dense connective tissue, which includes:
Blood Vessels
Fibroblasts
Mast Cells
Nerve Endings
Lympathetics
Elastic Fibers (interlaced)
Collagen Fibers (in parallel layers)
Papillary Dermis: most superficial, lies right underneath, made relatively of loose and connective tissue.
Capillaries
Elastic Fibers
Reticular Fibers
Collagen

5. Melanin
Definition: a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight.
Pigment comes in different shades depending on genetics.
Exposure to UV light(sun) will produce more melanin for protection.
Melanocyte (cell that produces melanin) size varies in different individuals and may lead to a difference in the amount of melanin produced per cell.
2 Types of Melanin:
Eumelanin is the main pigment and is a brownish color.
Pheomelanin is associated with red hair and freckles.

6. Skin Color - Evolutionary
Evolutionary Basis
Darker skin: natural sunscreen, reflects UV rays
Prevent folic acid deficiency
Found in areas near the Equator (Ex: Africans)
Lighter skin: helped to absorb the limited UV light
Needed to produce Vitamin D
Found near poles (Ex: Scandinavians, Europeans)

7. Skin Color - Biological
Melanocyte: Cell that produces melanin
2 types:
Eumelanin: Dark brown to black
Pheomelanin: Red to Yellow
More Eumelanin: Darker
More Pheomelanin: Lighter
Size of extensions dictate the amount of specific melanin released

8. Steps of Skin Growth

9. Steps

10. Questions What is melanin responsible for?
Tanning skin exposed to sunlight
Protecting skin
Producing melonocyte
Creating pigment
People with lighter skin have more of what type of melanin?
Eumelanin
Pheomelanin
Melanin
Dark Melanin
What are the two layers of dermis?
Papillary and Reticular
Epidermis and Papillary
Reticular and Melanin
Pigment and Hair
What is the second lowest cell step in skin growth?
Basal
Granular
Prickle
Surface layer
What is the purpose of the Epidermis layer?
Fight against diseases
Provide an outer layer of protection
Produce hair
Help with scar heeling