Colorado Cosmetology Written Practice Exam

Which is the lowest layer of the epidermis where cell growth occurs through mitosis?

1. Stratum corneum

2. Stratum germinativum

3. Stratum granulosum

4. Stratum lucidum

The correct answer is: Stratum corneum

The correct answer is the stratum germinativum, which is also known as the basal layer of the epidermis. This layer is crucial because it is where new skin cells are produced through the process of mitosis. As the cells divide, they gradually move up through the layers of the epidermis, ultimately becoming part of the outermost layer, which is the stratum corneum. The stratum corneum consists of dead, flattened cells that have been keratinized and serve as a protective barrier. The stratum granulosum is involved in the process of keratinization, where cells begin to lose their nuclei and become more flattened. The stratum lucidum is mainly found in thick skin areas, such as the palms of the hands and soles of the feet, and it does not participate in cell growth. Understanding the role of each layer of the epidermis is essential in the field of cosmetology, especially concerning skin health and treatments.