The Anatomy and Function of the Skin’s Outermost Layer Medically reviewed by Casey Gallagher, MD The epidermis is the outermost layer of the skin. The thickness of the epidermis varies depending ...

The outermost layer is the bloodless epidermis. The dermis includes collagen, elastin, and nerve endings. The innermost layer, subcutaneous fat, contains tissue that acts as an energy source ...

Thick keratin layer would restrict oxygen exchange and water absorption. Amphibians have many mucus glands to reduce water loss. As a result of this skin, they are restricted to moist, humid habitats.