two important functions of stratum granulosum
Answers
The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis.[1] Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer. These cells contain keratohyalin granules, which are filled with histidine- and cysteine-rich proteins that appear to bind the keratin filaments together. Therefore, the main function of keratohyalin granules is to bind intermediate keratin filaments together.
At the transition between this layer and the stratum corneum, cells secrete lamellar bodies (containing lipids and proteins) into the extracellular space. This results in the formation of the hydrophobic lipid envelope responsible for the skin's barrier properties. Concomitantly, cells lose their nuclei and organelles causing the granular cells to become non-viable corneocytes in the stratum corneum.
The stratum granulosum is the barrier between the stratum corneum of the skin and the underlying stratum spinosum. Cells from the stratum spinosum migrate into the stratum granulosum and they are called granular cells. These cells have keratohyalin granules in them; they are rich in proteins, which bind the keratin filaments together.
So, you could say that the stratum granulosum is the barrier between the inside and the outer keratin layer of the skin. This prevents unwanted chemicals or dirt from intruding into our bodies.