What is the outermost layer of the skin known as?

The outermost layer of the skin is known as the Stratum Corneum. This layer plays a crucial role in protecting the underlying tissues, acting as a barrier against environmental damage, moisture loss, and pathogens. The Stratum Corneum is composed mainly of dead skin cells that have become keratinized, meaning they are filled with the protein keratin. This process helps create a tough, protective layer that is essential for overall skin health.

Understanding the structure of the skin can also shed light on the functions of the other layers mentioned. The Stratum Spinosum is deeper in the skin and is involved in cellular connections and strength. The Stratum Lucidum is found only in certain areas of thick skin, such as the palms of the hands and soles of the feet. The Stratum Granulosum serves as a transition layer where keratinocytes begin to undergo keratinization, preparing to move up to the Stratum Corneum. Each of these layers has unique characteristics, but none serve the primary protective function of the outermost layer like the Stratum Corneum does.