Utah Master Esthetician Practice Exam

What is the lowest layer of the epidermis called?

1. Stratum corneum

2. Stratum lucidum

3. Stratum granulosum

4. Stratum germinativum (basal layer)

The correct answer is: Stratum germinativum (basal layer)

The lowest layer of the epidermis is called the stratum germinativum, also referred to as the basal layer. This layer is crucial for the regeneration of the skin, as it contains actively dividing cells known as keratinocytes. These cells migrate upwards to form the outer layers of the epidermis as they mature and undergo keratinization. The stratum germinativum is where melanocytes, which produce the pigment melanin, are also located. This contributes to skin color and provides some protection against UV radiation. This layer is fundamental not only for its role in continuous cell turnover but also for the overall health and integrity of the skin. In contrast, the other layers mentioned, such as the stratum corneum, stratum lucidum, and stratum granulosum, are positioned above the stratum germinativum. The stratum corneum is the outermost layer composed of dead, flattened keratinized cells, while the stratum lucidum is a thin, clear layer found only in certain areas of thick skin. The stratum granulosum is where cells begin to lose their nuclei and undergo the process of keratinization. Understanding the hierarchy and function of these layers is essential for mastering skin anatomy