How many layers compose the keratinized corneum layer?

The keratinized corneum layer, also known as the stratum corneum, is the outermost layer of the epidermis and is composed of approximately 15 to 20 layers of dead skin cells. This layer plays a critical role in protecting the underlying tissues from environmental damage, preventing water loss, and serving as a barrier against pathogens and chemicals. The cells within this layer are filled with keratin, a protein that contributes to the layer's strength and water resistance.

The number of layers can vary based on several factors, including body location, with certain areas of the skin having a thicker stratum corneum for added protection. However, the widely accepted range for the number of layers in the keratinized corneum is generally cited as being between 15 and 20, making this answer accurate. Understanding the structure and function of the stratum corneum is fundamental in esthetics, as it relates to skin health and the effectiveness of skincare treatments.