Keratinocytes are the primary cell type found in the epidermis, the outermost layer of the skin. These cells originate from the basal layer of the epidermis, where they are alive and constantly dividing. As they move towards the surface of the skin, they undergo a process called keratinization.
During keratinization, keratinocytes progressively lose their nuclei and other organelles, becoming more flattened and packed with keratin, a tough and fibrous protein. By the time they reach the skin’s surface, these cells are essentially dead. This transformation is crucial for our skin’s protective barrier function.
The dead keratinocytes form a tough layer that helps shield underlying tissues from mechanical damage, pathogens, and dehydration. It’s this layer that we see as the outermost part of our skin. When these keratinocytes eventually slough off, they are replaced by new ones that continue the cycle, ensuring our skin remains resilient and protective. Overall, the death of keratinocytes is a natural and essential aspect of skin health and maintenance.