What is the primary characteristic of the stratum lucidum?

The primary characteristic of the stratum lucidum is that it is located only on the palms of the hands and the soles of the feet. This thin, translucent layer of skin is found in areas where the skin is subject to greater friction and pressure, providing an additional protective barrier. The stratum lucidum is essentially made up of several layers of dead keratinocytes that provide toughness and protection. Its absence in other areas indicates a difference in skin thickness and function, reinforcing the specialization of skin types for varying roles throughout the body. Other options describe characteristics of different layers or structures within the skin, further emphasizing the uniqueness of the stratum lucidum.