Your skin is your body's largest organ. Because it's the first line of defense against external threats like chemicals, bacteria, and even viruses, it also plays a vital role in your health!
But did you know that this large organ actually has several layers... even though we only see one?
Today we're looking at the different layers of the skin and the role they play in protecting your body, regulating your body temperature, and more.
7 layers of the skin & their functions
The skin consists of three main layers: the epidermis, the dermis and the subcutaneous tissue.
Epidermis
The epidermis is the outermost (or topmost) layer of the skin. It's the only one visible to the naked eye. Within the epidermis are five layers.
Stratum corneum: The stratum corneum (the horny layer of the epidermis) is your topmost layer of skin. Because it's the outermost layer, it acts as your first line of defense against foreign invaders. This is also where your skin microbiome lives: it's home to trillions of microorganisms, including 1,000 different types of bacteria (more on their importance below).
Stratum lucidum: This layer of skin is only present in areas with thicker skin, such as the palms of the hands and the soles of the feet. Due to the accumulation of dead skin cells, the skin in the stratum lucidum appears clear.
Stratum granulosum: Glycolipids secreted in the stratum granulosum keep the skin cells connected to each other.
Stratum spinosum: This layer of the epidermis is also called the spinous layer. It is the thickest layer of the epidermis and contains dendritic cells that protect the body from potential infections.
Basal layer (Stratum germinativum): 90% of the cells in the epidermis are keratinocytes , which produce keratin, a fibrous protein that strengthens the skin. Keratinocyte production begins in the basal layer, the innermost layer of the epidermis. From there, they are pushed to the surface of the epidermis.
Besides keratinocytes for keratin production, the stratum basale also contains melanocytes, which produce melanin. Melanin is the pigment that determines your skin color.
Dermis
The dermis contains all your sweat and oil glands, as well as hair follicles, connective tissue, lymphatic vessels, and nerve endings. It also contains collagen and elastin.
This means that the dermis and its contents are responsible for many functions...
- Sweat glands produce sweat in response to heat and stress. When the sweat evaporates, it helps cool the body.
- Nerve endings in the dermis sense pain , touch, pressure, and even temperature.
- Blood vessels provide nutrients to the skin and also regulate body temperature.
- The oil glands secrete sebum that keeps the skin moist and soft and acts as a natural, protective barrier.
- Hair follicles produce the hair on your body. This hair helps regulate your body temperature and also provides extra protection.
The dermis is much larger than the epidermis. Although the epidermis forms an outer, protective, and visible layer of skin, the dermis is your body's most important protector. Thanks to its collagen and elastin content, it is also the most influential layer of the skin when it comes to forming skin structure.
Subcutaneous tissue
Beneath the dermis lies the hypodermis, also known as the subcutis. This layer insulates your body, keeping you warm. It also acts as a shock absorber or cushion around your vital organs.
The subcutis also connects the skin to the muscles and tissues beneath and contains blood vessels.
How Skin Care Products Affect the Layers of Your Skin
Most topical skincare products only penetrate the epidermis. Some products (such as retinoids) can reach the dermis, but this is far from the case for most skincare ingredients.
But when we look at the function of the epidermis, it is important that all ingredients in your products are beneficial and do not hinder the important functions of the skin.
When just the skin microbiome (on the top and outermost layer of the skin) is affected by topical chemicals, it compromises your natural protective barrier and your ability to ward off foreign invaders.
The damage that aggressive skincare ingredients can do to your skin microbiome can already damage the health of your entire skin.
That's why it's so important to choose products that are free from harsh chemicals, such as parabens, preservatives, and fragrances.
Because even though a product cannot penetrate deeply into the skin, it can still affect every other layer and overall health.
Conclusion
Your skin is a large and complex organ. Understanding how different skincare ingredients penetrate the skin and enter the bloodstream is a field of ongoing research.
Yet we know that even if a product only penetrates the surface of your skin, it can cause significant harm (or good!). This is largely because the skin microbiome, a delicate but vital ecosystem of microorganisms that protect the body, lives on the skin's surface.
The more we learn about the layers of the skin, the more we understand the importance of nourishing your body's largest organ with gentle, therapeutic skincare products – like Gladskin!
