What are keratinocytes primarily known for?

Keratinocytes are primarily known for making up the majority of the epidermis, the outermost layer of the skin. These cells play a crucial role in the skin's structure and function. They are responsible for producing keratin, a fibrous protein that provides strength and waterproofing properties to the skin. This protective barrier is vital for preventing water loss and shielding the underlying tissues from environmental damage and pathogens.

Understanding the role of keratinocytes is essential because they contribute significantly to the overall health of the skin. A healthy epidermis, dominated by keratinocytes, ensures that the skin can effectively carry out its protective functions. The other options, while mentioning important skin functions, do not accurately describe the primary function of keratinocytes. For example, muscle tissue formation is unrelated to skin cells, producing sweat is primarily the function of sweat glands, and regulating skin color is largely associated with melanocytes, which produce melanin.