Final answer:
The stratum lucidum is a layer of dead, flattened keratinocytes in the epidermis, found only in thick skin areas like palms and soles. These cells contain eleidin, which helps prevent water loss and contributes to the skin's protective barrier. It resides between the stratum granulosum and stratum corneum layers.
Step-by-step explanation:
Stratum Lucidum
The stratum lucidum is a distinctive layer of the epidermis found specifically in areas of thick skin such as the palms, soles, and digits. Within this layer, keratinocytes are dead and flattened, packed closely with a clear protein known as eleidin. Eleidin is a translucent protein derived from keratohyalin, and it plays a critical role in the skin's ability to prevent water loss. Located between the stratum granulosum and stratum corneum, the clear layer contributes to the protective barrier properties of the skin.
This layer's cells are responsible for the tough and waterproof quality of our skin nails and are eventually shed and replaced. It's worth noting that the stratum lucidum aids in the skin's translucency and helps protect the body against the external environment to some extent.