The skin is the largest organ in the body, with a total area of about 20 square feet. It protects from microbes and elements, helps to regulate body temperature, and allows the feeling of touch, heat, and cold.
What are the layers of the skin
Although you might not normally think of it as an organ, it is actually made of tissues that work together as one structure to perform unique and critical functions.
The skin and its ancillary structures form the integrative system, which provides the body with comprehensive protection. The skin consists of multiple layers of cells and tissues, which are attached to the body’s basic structures by the connective tissue.
The deep layer is connected to much of the vascularized blood vessels (it has many blood vessels). It also has many autonomic and sympathetic nerve fibers, which ensures communication to and from the brain.
It consists of two main layers: the epidermis, made of closely packed epithelial cells, and the dermis, made of dense and irregular connective tissue that includes blood vessels, hair follicles, sweat glands, and other structures. It is located under the dermis under the skin, which mainly consists of connective and fatty tissue.
Depending on the location of the skin in the body, the epidermal cells from the base to the surface are arranged in four or five layers.
Skin with four layers of cells is referred to as “thin skin.” From depth to surface, these layers are stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. Most of the skin can be classified as thin .
“Thick skin” is only found on the palms of the hands and soles of the feet. It is distinguished by having a fifth layer, called the stratum lucidum, and is located between the stratum corneum and granular layer.
The cells in all layers of the epidermis except the basal layer are called keratinocytes. Keratin Cell is the cell that makes and stores protein keratin. Keratin is a fibrous protein within cells that gives hair, nails, and skin its hardness and waterproof properties. Keratinocytes in the stratum corneum are dead and fade regularly, and are replaced by deep layer cells
These layers can be divided in another way into 3 main sectors
- the epidermis, which is the outermost layer of skin, acts as a waterproof barrier and creates our skin tone.
- The dermis or dermis under the epidermis contains solid connective tissue, hair follicles, and sweat glands.
- Hypodermis The deepest subcutaneous tissue is composed of fatty and macrophages.
Skin color is created by special cells called melanocytes, which produce melanocytes. The melanocytes are located in the epidermis.