Colorado Esthetician Written Practice Exam

Which layer of the epidermis is composed of cells that resemble granules and are filled with keratin?

1. Stratum Basale

2. Stratum Corneum

3. Stratum Granulosum

4. Stratum Lucidum

The correct answer is: Stratum Basale

The stratum basale is the deepest layer of the epidermis and contains cells that are actively dividing and pushing older cells towards the surface. These cells are filled with keratin and eventually become flattened and form the outer layers of the skin. The stratum corneum is the outermost layer of the skin, and although it also contains keratin, the cells in this layer are already dead and serve to protect the skin from external elements. The stratum granulosum is the layer above the stratum basale and contains cells that are beginning to produce keratin and form granules, but they are not fully developed yet. The stratum lucidum is a clear layer found in areas with thick skin, such as the soles of the feet and palms of the hands, and is not typically seen in other parts of the body. Therefore, the correct answer is A because the cells in the stratum basale are actively producing keratin and forming granules.