What Is the Stratum Granulosum?

It is located in the shallow layer of the spiny cell layer, and is composed of 2 to 3 layers of cells. The cell arrangement is parallel to the skin surface, the cells are spindle-shaped, the nucleus is oval, is located in the center, and the staining is lighter, which is a manifestation of beginning to degenerate. The periphery of the cytoplasm is densely packed with tension fibril bundles, and the number of membrane coating particles is increased, which contains phospholipids and mucopolysaccharides. As the granular layer cells continue to keratinize, the contents such as mucopolysaccharides and phospholipids are continuously discharged from the membrane by the particles and enter the interstitial space, forming a part of the intercellular substance, making the binding force between the surface cells stronger. And can prevent foreign objects from invading. There are obvious transparent horny particles around the nucleus, which are highly refractive, and H and E stained with dark purple blue, showing strong basophilicity. Observed under an electron microscope, transparent colloidal particles are high-density protein clumps or particles of varying sizes and shapes without membrane coating.

It is located in the shallow layer of the spiny cell layer, and is composed of 2 to 3 layers of cells. The cell arrangement is parallel to the skin surface, the cells are spindle-shaped, the nucleus is oval, is located in the center, and the stain is lighter, which is a manifestation of beginning to degenerate. The periphery of the cytoplasm is densely packed with tension fibril bundles, and the number of membrane coating particles is increased, which contains phospholipids and mucopolysaccharides. As the granular layer cells continue to keratinize, the contents such as mucopolysaccharides and phospholipids are continuously discharged from the membrane by the particles and enter the interstitial space, forming a part of the intercellular substance, making the binding force between the surface cells stronger And can prevent foreign objects from invading. There are obvious transparent horny particles around the nucleus, which are highly refractive, and H and E stained with dark purple blue, showing strong basophilicity. Observed under an electron microscope, transparent colloidal particles are high-density protein clumps or particles of varying sizes and shapes without membrane coating.

Chinese name

Granular layer

Foreign name

stratum granulosum

lie in

Superficial layer

Make up

2-3 layers of cells

Granular layer The effect of granular layer on skin regeneration

Regeneration of the skin under normal conditions is mainly due to the renewal of the epidermis. The morphological characteristics of cells in each layer of the epidermis seen in vertical skin slices are a reflection of the epidermal renewal process. Basal cells are mitotically active. Some newborn cells began to differentiate and gradually synthesized keratin while moving to the superficial layer. Cells undergo changes in spine cells, granular layer cells, and clear layer cells, move into the stratum corneum, and gradually fall off. The mitotic and keratinocytes of the basal layer cells are shed to maintain the normal structure of the epidermis. The length of the epidermal renewal period varies from body to body, usually about 20 to 30 days.

There is a considerable difference in the degree of regeneration after skin injury due to the degree of injury. Cuts to the skin, bleeding and necrosis of the thin layer of tissue first. Later, the epidermal cells around the wound became larger and moved under the clotting to cover the dermis. Later, the epithelial cell layer increased and began to keratinize. The response of the dermis is, first of all, the appearance of many white blood cells and macrophages in the wound area, removing bacteria and necrotic tissue. In the future, fibroblasts will increase and become active, repair the defective connective tissue, and new capillaries will grow in. If there are many defects in the epidermis and connective tissue, connective tissue and blood vessels grow first, repair the defect, and then induce epidermal growth. The epidermis around the wound and the hair follicles and sweat glands remaining on the wound surface can regenerate the epidermis. The newly born epidermis gradually spread to cover the injured surface. Later, the number of layers of epidermal cells increased and keratinized.