What layer of the skin is referred to as the outer layer of friction skin?

The outer layer of friction skin is correctly identified as the epidermis. This layer serves as the first line of defense against external elements and is particularly important in areas where there is frequent friction, such as the fingertips and palms.

Within the epidermis, the stratum corneum represents the outermost layer comprised of dead, flattened skin cells, which is crucial in protecting underlying structures from environmental damage. However, it's essential to understand that the term "friction skin" refers specifically to the epidermis as a whole, rather than exclusively to this uppermost layer.

The dermis is situated beneath the epidermis and contains connective tissue, blood vessels, and nerves, playing a supportive role rather than being an outer layer. The stratum malpighii, also known as the stratum basale and stratum spinosum, constitutes a deeper layer of the epidermis involved in the production of new skin cells. Therefore, the identification of the epidermis as the outer layer of friction skin fully encapsulates its protective and structural importance.