Final answer:
The protein found in large amounts in the outermost layer of epidermal cells is keratin, not collagen. Keratin is produced by keratinocytes in the epidermis and forms a protective layer, while collagen is primarily found in the dermis. The skin can continuously regenerate due to stem cells, which replace shed cells.
Step-by-step explanation:
The statement that the protein found in large amounts in the outermost layer of epidermal cells is collagen is false. The primary protein found in the outermost layer of epidermal cells, specifically in the stratum corneum, is keratin. Collagen, on the other hand, is a fibrous protein that contributes to the tensile strength of connective tissue, which is predominantly found in the dermis layer of the skin.
Keratinocytes in the epidermis are responsible for producing keratin. These cells go through a process known as keratinization, where they become filled with keratin as they move from the lowest layer of the epidermis to the outermost layer. Moreover, melanocytes, which produce melanin, can be found within these keratinocytes. When the keratinized cells reach the surface, they are dead and create a protective, waterproof barrier. This layer helps to protect underlying tissues and also reduces microbial growth on the skin's surface.
Our skin is not permanently damaged when the surface layers are rubbed off, such as when using a rough washcloth, because the epidermis continuously regenerates. Stem cells at the base of the epidermis divide to create new cells that replace the ones that are shed from the surface. These new cells are always moving upward, replacing older cells, and ensuring that the skin can recover from surface abrasions.