What is the uppermost layer of the epidermis called?

The uppermost layer of the epidermis is known as the stratum corneum. This layer consists of dead, flattened skin cells that are rich in keratin, providing a protective barrier to the underlying layers of the skin. The primary function of the stratum corneum is to protect against environmental damage, prevent water loss, and to support the skin's overall structure and integrity.

It's important to understand that the other layers mentioned play significant roles in the overall function of the epidermis, but they are located beneath the stratum corneum. For instance, the stratum granulosum is involved in the process of keratinization, where cells begin to die and become part of the barrier layer, while the stratum lucidum is a thin layer found only in certain areas of thicker skin, such as the palms or soles. The stratum spinosum provides strength and flexibility to the skin due to its network of desmosomes connecting the cells, but these layers do not represent the outermost boundary of the epidermis. Understanding the unique characteristics and functions of each layer enhances the knowledge of skin structure and care.