Layers of the Skin and their Functions


Did you know that the skin is the largest organ in the body? In this short blog post, we will discuss the main layers in the skin and their functions. 


As you learned in elementary school, the skin is made up of three main layers: the epidermis, dermis, and subcutaneous layer. Within those layers are cells that all have important functions. These functions aid in the healing and aging process of the skin.


Let’s start with the epidermis. In a nutshell, the main functions of the epidermis are to naturally exfoliate the skin and retain surface lipids. These two functions are essential for strong barrier function. Keratinocytes make up approximately 90 percent of the cells in the epidermis. These cells mature and exfoliate constantly and should mature every six weeks. The function of keratinocytes is to provide barrier function and UV protection. Natural skin exfoliation decreases with age and is suppressed with moisturizers* and disease. 


In the deepest part of the epidermis, melanin is produced. Its main function is to protect the skin from harmful UV rays and is where a person’s skin color is determined. This protection is limited, though, and SPF must be applied daily. Due to injury or disease, melanin will start to distribute vertically instead of horizontally. This presents in the form of sunspots, melasma, and other forms of hyperpigmentation. 


In between the epidermis and dermis is a layer called the epidermal-dermal junction, or EDJ. Within this layer are fibers called anchoring fibrils. When the skin experiences a loss of anchoring fibrils, fine lines begin to form. When you smile and your eyes crinkle, the anchoring fibrils begin to break down, causing crow’s feet. The same happens whenever you are constantly moving your face. 


The dermis has many different layers and functions, but we’ll focus on the papillary dermis. This layer must be activated in order to prevent aging. Collagen and elastin both keep us looking youthful. As we age, our collagen and elastin production slows down, and activating these cells is vital to combat aging. Fibroblasts within the papillary dermis are responsible for dermal renewal, repair, and support. Fibroblasts also produce collagen, elastin, glycosaminoglycans, and modulating enzymes.


Finally, the subcutaneous layer is composed of cells called lipoblasts and lipocytes. These cells are important because they produce and maintain fat lobules. These cells are active until age eighteen, or until the end of natural body growth. These cells aid in maintaining volume (contour), cushioning (trauma protection), and energy storage. Filler can replace lost volume in the cheeks, jaw, chin, and lips. 


In order to maintain complete skin health, all layers of the skin must be addressed. That’s why Desert Bloom Plastic Surgery is committed to achieving overall wellness and skin health. 


*Dr. Zein Obagi theorizes that moisturizers are damaging to the skin. He believes using moisturizers occasionally is acceptable, but to depend on them to hydrate and calm the skin on a daily basis is damaging to the skin.