What is keratinization?

Keratinization is the process by which cells become filled with keratin, a fibrous protein that provides structure and protection to the skin and its derivatives, such as hair and nails. This process occurs in the epidermis, the outermost layer of skin, where keratinocytes, the predominant cell type, undergo a transformation as they move from the deeper layers of the epidermis to the surface. During this migration, keratinocytes accumulate keratin, which leads to the hardening and waterproofing of the skin. Ultimately, as these cells reach the skin's surface, they die and form a protective barrier that helps prevent water loss and shields underlying tissues from environmental damage.

Understanding keratinization is crucial for appreciating how the skin maintains its integrity and functionality. The other processes mentioned do not pertain to keratinization; cell division relates to the proliferation of cells, forming new blood vessels pertains to angiogenesis, and fat storage in cells involves adipocytes rather than keratin production.