Exactly how many layers of skin do humans have? Well, human skin is composed of three layers: the epidermis, the dermis and the hypodermis. These three layers of skin each have their own separate functions and make up the human body’s largest organ. Let’s take a look at each layer of skin in detail to understand the exact function and purpose of each.
The first layer of skin we’re going to look at is the epidermis – the only layer visible to the eye. Its primary purpose is to protect the human body from the dangerous environment around us.
Made up of 95% keratinocytes which produce keratin, a tough waxy protein that makes the skin strong, the epidermis doesn’t contain any blood vessels and protects the human body in a variety of ways. The main functions of the epidermis are:
- Providing a waterproof barrier
- Producing melanin to give colour to the skin and reduce the absorption of UV radiation
- Regulating the amount of water released from the body
- Providing an immune barrier
The epidermis itself is made up of four of five layers, or strata (depending on which part of the epidermis is being examined), including:
- Stratum germinativum
- Stratum spinosum
- Stratum granulosum
- Stratum corneum
- Stratum lucidum
Each layer of the epidermis has its own function, ensuring that the body is well protected from water, infection and sunlight. It also does a pretty good job of keeping all of our other vital organs contained within us!
The dermis is the thickest layer of skin. It sits between the epidermis and the hypodermis and consists of two distinct layers – the papillary dermis and the reticular dermis. The dermis is primarily made up of fibrous and elastic tissue, which gives skin its overall flexibility and strength. Its primary role is to support the epidermis, whilst allowing the skin to thrive.
The dermis is also where you’ll find fibroblasts. Fibroblasts are the most common cells of connective tissue in the body and are the only cells that can make Type III collagen – a protein produced by the body. Collagen decreases in quality as the body ages and can be a sign of ageing, causing wrinkles and sagging. Many people choose to use ‘fibroblasting’ or plasma treatments to repair and reverse the signs of ageing.
This second layer of skin also contains nerve endings, sweat glands, sebaceous glands, hair follicles and blood vessels – each with their own functions and purposes.
Nerve endings detect temperature, touch, pressure, pain and any other outside stimuli which could cause harm to the skin. They serve to protect us from the environment around us and are a vital component of the dermis, which keeps humans safe from burns and helps us to appreciate the sensation of touching something pleasant.
Hair follicles produce hair which acts as protection against injury, whilst regulating body temperature.
The production of sweat is vitally important as it helps the body to cool down in response to heat or stress.
Similar to the sweat glands, sebaceous glands secrete sebum, an oily substance which you are most likely to find on your face’s T-zone. Sebum helps to keep the skin moist and helps prevent the entry of harmful substances.
Blood vessels have two primary functions: to carry nutrients and waste to and from where we need them and to dilate and contract to release or retain heat. This keeps the body warm or cold depending on external temperatures.
The hypodermis layer
The final layer of skin that humans have is the hypodermis, also known as the subcutaneous layer or superficial fascia. It sits below both the epidermis and dermis. The hypodermis’ primary function is to connect the skin to bones and muscle, as well as producing the hormone leptin, which gives us the sensation of being full.
The hypodermis is also home to our fat stores, which are important for insulation and as an energy reserve. It also provides us with adequate cushioning against trauma.
The part of the body that accumulates fat depends on hormones and gender. This can also change as the body ages and develops. For men, most fat stores are found in the abdomen and shoulders, whereas for women it’s found in the hips, thighs and bottom.
Hopefully, you now have a much clearer idea about how many layers of skin we have and their purpose. For more information on how you can reverse the signs of ageing, without the need for surgery, speak to PlasmaPen.