What is the main function of keratinocytes?

Keratinocytes are the predominant cell type found in the epidermis, which is the outermost layer of the skin. Their primary function is to produce keratin, a fibrous protein that plays a crucial role in the structure and protection of the skin. Keratin provides strength and waterproofing to the skin, helping to create a barrier that protects underlying tissues from environmental damage, pathogens, and dehydration.

As keratinocytes migrate from the deeper layers of the epidermis to the surface, they undergo a process called keratinization, where they become filled with keratin and eventually die, forming a tough, protective outer layer of skin. This process is vital for maintaining the integrity and resilience of the skin.

While the other options reference important functions related to the integumentary system, they do not pertain to the main role of keratinocytes. For instance, melanin production is carried out by melanocytes, sensory receptor functions are performed by specialized cells such as Merkel cells, and blood flow regulation is primarily managed by the vascular components of the skin. Therefore, the correct and fundamental role of keratinocytes is the production of keratin.