Skin is both tough and elastic.
It is moist on the inside, relatively dry on the outside. It helps regulate Sparky's body temperature through the blood vessels and reduces exposure to extreme cold by muscular action that fluffs the hair and traps heated air next to the body. In short, skin is a wonderful invention. The epidermis is the body's environmental shield made up of tough keratinized cells glued together in stacks by fats. The epidermis is a barrier against injury, disease, and damage from ultraviolet light.