What is the correct order of the layers of the epidermis from superficial to deep?

The correct order of the layers of the epidermis from superficial to deep is as follows: stratum corneum, stratum lucidum, stratum granulosum, and stratum basale.

The stratum corneum is the outermost layer, composed of dead, flattened keratinocytes that provide a barrier to the environment. Beneath that is the stratum lucidum, which is found only in certain areas of thick skin and serves to provide an additional layer of protection. Next is the stratum granulosum, where cells begin to lose their nuclei and start to keratinize, contributing to the skin's waterproof barrier. Finally, the stratum basale is the deepest layer, where active cell division occurs, giving rise to new keratinocytes that will move up through the layers of the epidermis.

Understanding the arrangement of these layers is essential for grasping how skin functions in protection, barrier formation, and regeneration.