Skin Structure – Starting from the outside of the skin (visible part) to the inside, we can differentiate three layers that make up the structure of our skin. These three layers are the epidermis, the dermis, and the hypodermis.
The epidermis is the top superficial layer of the skin. This layer is the one we can see and touch. It is always in a continuous process of regeneration and desquamation of dead cells. Later, we will know the epidermis layers involved in this process.
The primary function of the epidermis is to act as a protective shield. Without realizing it, we constantly receive external attacks by bacteria, fungi, parasites, ultraviolet radiation, and endless toxic substances. However, the epidermis comprises five layers (or strata) and contains four types of cells.
The Five Layers Of The Epidermis
- Basal layer – It is the earnest layer of the epidermis. In this layer, the pigmentation responsible for giving color to the skin is formed through the melanocytes.
- Spinous layer – It receives this name due to the resemblance to the spines that the cells acquire in it.
- Granular layer – The cells involving in the production of keratin are found.
- Clear or lucid layer – This layer is skinny and is only be present in the thickest parts of the skin structure.
- Horny layer – It is the most superficial layer of the epidermis. It is where the dead cells are found that are shed through the process called desquamation.
The Epidermis Contains Four Types Of Cells
- Keratinocytes: They are the most abundant cells and those that produce keratin(protein fibers); they represent 80% of all the cells of the epidermis.
- Melanocytes are the cells responsible for producing melanin(the pigment that gives color to the skin).
- Langerhans cells: They involve in the immune system.
- Merkel cells – It is associated with nerve endings.
The epidermis cells migrate from the deepest layer (basal layer) to the most superficial layer (stratum corneum). In this process, which under normal circumstances usually lasts 30 days, the cells undergo a series of changes that give rise to skin regeneration.
The Main Components Of The Dermis
- Collagen and elastin fibers – They give firmness and elasticity to the skin. However, over the years, the production of collagen and elastin decreases, which causes the appearance of unwanted wrinkles.
- Blood vessels are responsible for providing the necessary nutrients to the epidermis.
- Sebaceous glands: They are the ones that produce the sebum that allows lubrication and protects the skin.
- Sweat glands: They regulate body temperature through sweat and help maintain the level of acidity and fat in the skin.
- Nerve endings – Through them, we can perceive sensitivity and touch.
- Hair follicles – They are responsible for hair growth.
It is the last layer of the skin. It mainly comprises adipose cells that form fatty (or adipose) tissue. This fatty tissue is responsible for storing the energy reserve that we may need in the form of fat. In addition, it serves as thermal insulation against possible heat losses.
Depending on the person and the area of the body, these fat cells can vary. For example, in women, they are found in more significant numbers in the areas of the thighs and buttocks. In the case of men, it is usually the abdominal area.
Hypodermis also helps the consistency and mobility of the skin structure. In addition, it serves as a cushion against the impacts we can receive from the outside and provides insulation to the internal organs.
Skin is the main sense organ in the human body. It covers most of the area of the body. Proper care and nutrition are necessary to maintain skin health. However, the skin protects the internal organs from various harmful materials.