Epidermis

What is the epidermis layer of skin?

Your skin has three main layers, and the epidermis (ep-uh-derm-us) is the outermost layer in your body. The other two layers of skin are the dermis and hypodermis. The epidermis is the thinnest layer of skin, but it’s responsible for protecting you from the outside world, and it’s composed of five layers of its own.

What are the layers of the epidermis?

The layers of the epidermis in order are:

• Stratum basale (stratum germinativum; pronounced stray-tum bay-say-lee or stray-tum germ-in-a-tie-vum). The stratum basale is in the deepest layer of your epidermis. New skin cells develop in this layer. It also contains the keratinocyte (cur-at-in-o-site) stem cells, which produce the protein keratin. Keratin helps form hair, nails and your skin’s outer layer, which protect you from the harsh environment. It also contains melanocytes (mel-ann-o-sites), which are responsible for producing melanin, which provides the pigment of your epidermis.
• Stratum spinosum (pronounced stray-tum spin-o-sum). The stratum spinosum is between the stratum basale and granulosum layers. This layer mostly consists of keratinocytes held together by sticky proteins called desmosomes (dez-mo-soam). The stratum spinosum helps make your skin flexible and strong.
• Stratum granulosum (pronounced stray-tum gran-yoo-lo-sum). The stratum granulosum is between the stratum spinosum layer and the stratum lucidum layer. Keratinocytes have granules within them, which are visible under a microscope in this layer.
• Stratum lucidum (pronounced stray-tum loo-sid-um). The stratum lucidum is between the stratum granulosum and the stratum corneum. It’s a thin, transparent layer of keratinocytes that are becoming less round and have a flatter shape.
• Stratum corneum (pronounced stray-tum corn-ee-um). The stratum corneum is the top layer of the epidermis. This is the layer you see. In the stratum corneum, keratinocytes become corneocytes (corn-ee-o-site). Corneocytes are strong, dead keratinocytes that protect you from harm, including abrasions, light, heat and pathogens. This layer also consists of fats that keep water from easily entering or leaving your body. The corneocytes eventually shed as new keratinocyte cells develop in the stratum basale layer and move through the other layers of skin.

What is the definition of epidermis?

The word “epidermis” combines the Ancient Greek prefix epi-, which means “outer,” and the Ancient Greek word derma, which means “skin.” So the word translates to “outer skin.”

What is the difference between epidermis and dermis?

The epidermis and the dermis are the top two layers of skin in your body. The epidermis is the top layer, and the dermis is the middle layer. The dermis exists between the epidermis and the hypodermis.

While the epidermis is the thinnest layer of skin, the dermis is the thickest layer of skin. The dermis contains collagen and elastin, which help make it so thick and supportive of your skin’s overall structure.

All of your connective tissues, nerve endings, sweat glands, oil glands and hair follicles exist in the dermis as well as the hypodermis.

What are the functions of the epidermis?

Each layer of your skin works together to keep your body safe, including your skeletal system, organs, muscles and tissues. The epidermis has many additional functions, including:

• Hydration. The outermost layer of the epidermis (stratum corneum) holds in water and keeps your skin hydrated and healthy.
• Producing new skin cells. New skin cells develop at the bottom layer of your epidermis (stratum basale) and travel up through the other layers as they get older. They reach the outermost layer of your epidermis after about a month, where the skin cells shed from your body as new cells develop at the bottom layer.
• Protection. The epidermis acts like armor to protect your body from harm, including ultraviolet (UV) radiation, pathogens (bacteria, viruses, fungi and parasites) and chemicals.
• Skin color. The epidermis has cells called melanocytes which make melanin, which is a group of pigments in your skin that provides skin color.

How does the epidermis help with other organs?

In conjunction with your other layers of skin, the epidermis protects your skeletal system, organs, muscles and tissues from harm.

Where is the epidermis located?

The epidermis is the top layer of your skin, and it’s what you see or feel when you look at or touch another person.

What color is the epidermis?

Melanocyte cells make melanin, which is a natural skin pigment that determines the color of your skin. Melanocytes produce two types of melanin that help determine how much pigment you have:

• Eumelanin: This type of melanin primarily makes dark colors in your hair, skin and eyes.
• Pheomelanin: This type of melanin primarily makes pink or red colors in your body, including lips, nipples, the vagina and the bulbous structure at the end of the penis (glans), as well as hair.

How big is the epidermis?

The epidermis varies in thickness throughout your body. In areas of skin that experience a lot of use, like the soles of your feet and the palms of your hands, the epidermis is thicker. These areas can be as thick as 1.5 millimeters, which is about as thick as two credit cards stacked together.

The epidermis is thinner in other areas of your face. For example, the epidermis layer in your eyelids is about 0.05 millimeters thick, which is about as thick as a sheet of copy paper.

What are the 3 major cells that make up the epidermis?

The epidermis contains different types of cells, including:

• Keratinocytes: Keratinocytes produce the protein keratin, which is the main component of the epidermis.
• Melanocytes: Melanocytes make your skin pigment, known as melanin.
• Langerhans cells: Langerhans cells prevent things from getting into your skin.

What are the common conditions and disorders that affect the epidermis?

Some common conditions and disorders that affect the epidermis include:

• Acne.
• Boils.
• Dandruff.
• Eczema.
• Melanoma.

What are common signs or symptoms of epidermis conditions?

Some common signs or symptoms of conditions that can affect your epidermis include:

• Dark spots or growths that change shape or color.
• Dry or cracked skin.
• Peeling or eroding skin.
• Scaly skin.

What are some common tests to check the health of the epidermis?

Your healthcare provider will conduct a physical exam of your epidermis to check for any possible symptoms or conditions. They may also perform the following tests:

• Allergy skin tests. Allergy skin tests determine if allergens are causing conditions in your epidermis.
• Blood tests. Blood tests can diagnose allergens or diseases.
• Skin biopsy. A skin biopsy can detect diseases, infections or cancer.

If you have melanoma, you may need further imaging tests to determine if it has spread.

What are common treatments for the epidermis?

Some common treatments for conditions that affect your epidermis include:

• Antibiotics. Oral antibiotics treat many skin conditions, including infections, dry or cracked skin and boils.
• Antifungal medications. Antifungal medications include creams, ointments, gels, sprays, powders or oral medications. They treat fungal infections in your skin.
• Corticosteroids. Corticosteroids reduce inflammation and tissue damage.
• Retinoids (vitamin A derivatives). Retinoids break up acne and help to prevent clogged pores.

Simple lifestyle changes/tips to keep your skin healthy.

• Establish a skin care routine, and follow your healthcare professional’s recommendations for keeping your skin healthy.
• Use a mild soap for your bath or shower, and pat your skin dry instead of rubbing it. Apply a moisturizing cream or ointment immediately after drying your skin to help seal in the moisture. Reapply cream or ointment two to three times a day.
• Take baths or showers with lukewarm water, not hot water.
• Drink at least eight glasses of water each day. Water helps keep your skin moist.
• Eat antioxidant-rich foods, including fruits, vegetables, beans, fish that are high in omega-3 fatty acids and nuts.
• Avoid sudden changes in temperature and humidity.
• Limit your exposure to known irritants and allergens.
• Use sunscreen with an SPF of at least 30.
• Avoid scratching or rubbing irritated skin.

A note from Cleveland Clinic

The epidermis is the top layer of skin in your body. It has many important functions, including protecting your body from the outside world, keeping your skin hydrated, producing new skin cells and determining your skin color. It’s important to take care of your epidermis. You can help take care of your skin by drinking plenty of water, eating antioxidant-rich foods and regularly using sunscreen with an SPF of at least 30.