What is the function of stratum lucidum? Where is this layer found?
The stratum lucidum is a thin clear layer of dead skin cells in the epidermis.
It is a thin transitional layer of epidermis found between the horny and granular layers of the skin. It is readily visible by light microscopy in areas of thick skin, which are formed on the palms of the hands and soles of the feet. However in the rest of the body where the skin is thinner this stratum does not appear differentiated from the granular region.
The stratum lucidum layer is composed of three to five layers of dead flattened keratinocytes. These cells do not show distinct boundaries and are filled with eleidin, an intermediate form of keratin. They are surrounded by an oily substance. The thickness of the stratum lucidum is controlled by the rate of mitosis of the epidermal cells.
The stratum lucidum is responsible for the capability of the skin to stretch. It also contains a protein that is responsible for the degeneration of skin cells. This thick layer also lowers the effects of friction in skin, especially in regions like the soles of feet and palms of hands. It is responsible for making the skin waterproof.