Stratum granulosum

The stratum granulosum is three to five cell layers thick in thick skin and is composed of cells filled with prominent, basophilic, keratohyalin granules. These granules combine with tonofilaments (keratin intermediate filaments) to produce keratin. Simultaneously, the organelles in these cells degenerate, resulting in keratinized scales, which form the stratum corneum.  200x, 1000x

The stratum granulosum is three to five cell layers thick in thick skin and is composed of cells filled with prominent, basophilic, keratohyalin granules. These granules combine with tonofilaments (keratin intermediate filaments) to produce keratin. Simultaneously, the organelles in these cells degenerate, resulting in keratinized scales, which form the stratum corneum.  200x, 1000x

The stratum granulosum is three to five cell layers thick in thick skin and is composed of cells filled with prominent, basophilic, keratohyalin granules. These granules combine with tonofilaments (keratin intermediate filaments) to produce keratin. Simultaneously, the organelles in these cells degenerate, resulting in keratinized scales, which form the stratum corneum.  200x, 1000x

The stratum lucidum is a clear layer of non-nucleated, flattened cells that is only visible in thick skin. It is often considered to be a subdivision of the stratum corneum. In this layer, proteins contained in the keratohyalin granules mediate the aggregation of bundles of tonofilaments.

As the keratohyalin granules combine with the tonofilaments, the nuclei and organelles in the cells degenerate, resulting in keratinized scales which form the stratum corneum.