Your skin is your largest organ and also one of the most misunderstood organs in terms of structure and function. There are so many bloggers, YouTubers, and influencers out there spreading misinformation and myths about the skin like facts without understanding how the skin works. As giant nerds who love the skin, our aim is to create products that work with the skin and share accurate information about the skin and how best to keep it healthy.
Your skin is made up of 3 distinct layers – the epidermis, dermis, and hypodermis.
The epidermis is a thin layer of skin. It is the most superficial layer of skin, the layer you see when you look at your body. Functions of the epidermis include touch sensation and protection against microorganisms and other foreign substances.
The epidermis is further divided into five, separate layers. In order from most superficial to deepest, they are the:
This layer is composed of the many dead skin cells that you shed into the environment—as a result, these cells are found in dust throughout your home. The cells of this layer are surrounded by lipids (fats) that help to repel water (which is why you don’t absorb all the water from your shower).
This layer is found only on the palms of the hands, fingertips, and the soles of the feet.
This is the layer where part of keratin production occurs. Keratin is a protein that is the main component of skin.
This layer gives the skin strength as well as flexibility.
This is where the skin’s most important cells, called keratinocytes, are formed before moving up to the surface of the epidermis and being shed into the environment as dead skin cells.
This layer also contains melanocytes, the cells that are largely responsible for determining the color of our skin and protecting our skin from the harmful effects of UV radiation.
The dermis lies beneath the epidermis and is rich in blood vessels that supply the skin with oxygen and nutrients. The blood vessels also allow immune cells to come to the skin to help fight infection. The dermis also contains nerves that help us relay signals coming from the skin including touch, temperature, pressure, pain, and itching. In addition, the dermis is home to sebaceous (oil-producing) glands and hair follicles. This layer also provides architecture and structure to the skin with networks of collagen and elastin.
They hypodermis is deeper than the dermis and consists of subcutaneous fat, blood vessels, and nerves. Its main purpose is to cushion and insulate the body.
Functions of the Skin
Your skin has 3 main functions: protection, regulation, and sensation.
The primary function of the skin is to act as a barrier. The skin provides protection from mechanical impacts and pressure, variations in temperature, micro-organisms, radiation, and chemicals. This is where the controversy of how much our skin actually absorbs and what penetrates through our skin becomes interesting and far black and white but we will get into that in a future article.
The skin regulates several aspects of physiology, including body temperature via sweat and hair, and changes in peripheral circulation and fluid balance via sweat. It also acts as a reservoir for the synthesis of Vitamin D.
The skin contains an extensive network of nerve cells that detect and relay changes in the environment. There are separate receptors for heat, cold, touch, and pain.