What layer of the epidermis is known as the granular layer?

The layer of the epidermis known as the granular layer is indeed the stratum granulosum. This layer plays a crucial role in the skin's barrier functionality. The stratum granulosum is situated above the stratum spinosum and below the stratum lucidum (in thick skin) or the stratum corneum.

In this layer, keratinocytes begin to lose their nuclei and cytoplasmic organelles, undergoing a process called keratinization. The cells here contain numerous granules, which are rich in keratohyalin and other proteins that help bind keratin filaments together. These granules also contribute to the formation of the skin's waterproof barrier, preventing water loss and protecting against external environmental factors.

This makes the stratum granulosum essential not only for maintaining the integrity of the skin but also for ensuring that moisture levels are balanced, making it crucial for overall skin health.