Table of ContentsView AllTable of ContentsAnatomyFunctionInteractionsConditions
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Interactions
Conditions
The integumentary system is the body’s outermost layer. Composed of skin, hair, nails, glands, and nerves, its main job is to protect your insides from elements in your environment, like pollution and bacteria. It also helps retain bodily fluids, eliminate waste products, andregulate body temperature.
This article digs into the specifics about each part of the integumentary system, exactly what it does, how it interacts with other body systems, and some of the medical conditions that can affect it.
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What Makes Up the Integumentary System?
The integumentary system includes:
Skin
The skin is the largest and heaviest organ of the body. To function as a protective barrier, it must cover the entire outside of the body, from the top of a person’s head to the end of the toes. The skin is approximately 2 mm (0.079 inches) thick and in its entirety weighs nearly 6 pounds.
Although there may be some differences in the skin from one person to another (such as the color, texture, and thickness), all skin has a few primary similarities. For example, every person’s skin is comprised of different types, including:
Layers of the SkinThere are two layers of the skin:The epidermis:The outer layer of the skin that makes up its strong protective covering.The dermis:Located under the epidermis; most of the structures of the skin are located in the dermis (such as various types of glands and hair follicles).
Layers of the Skin
There are two layers of the skin:The epidermis:The outer layer of the skin that makes up its strong protective covering.The dermis:Located under the epidermis; most of the structures of the skin are located in the dermis (such as various types of glands and hair follicles).
There are two layers of the skin:
The fatty layer of the skin is a layer of subcutaneous (under the skin) tissue, also known as the hypodermis.The fatty layer serves many different functions, including:
Hair
Hair serves to:
Hair is primarily comprised of a fibrous protein and contains a very small amount of lipids (fats) and water. Hair comes from follicles, which are simple organs made up of cells called epithelial cells.Epithelial cells are the cells that line the organs and function to provide a protective barrier.
Hair also has a bio-psycho-social function, influencing how we interact with others.
Nails
Just like other body parts,nails consist of several segments, including:
The function of the nail is:
Glands
The integumentary system has four types of exocrine glands, which are glands that secrete some type of substance outside the cells and body, such as onto the skin.
The four exocrine glands associated with the integumentary system include:
What Does the Integumentary System Do?
Overall, the integumentary system functions to guard the body, providing a barrier to infection and shielding the body against temperature changes and the adverse effects of potentially harmful substances (such as UV light).
The integumentary system has many specific roles in its involvement in helping to protect and regulate the body’s internal functions. Here are some ways that the skin, nails, hair, glands, and nerves of the integumentary system work:
Protection From Injury
The epidermis is composed of skin cells that contain a high content of keratin, a protein that provides protection from the external environment.
Keratin helps protect tissues, organs, and structures from injury, like:
Fatty Layer Protection
Protection Against Infection
The skin creates an acidic pH environment in which microorganisms find it difficult to grow, therefore protecting from infection.
Protection With Sweat
Many different types of microorganisms encounter the skin, but these organisms are not able to penetrate healthy skin. However, when a cut or other injury that causes an opening in the skin occurs, the organisms on the skin are no longer harmless as they enter the skin’s barrier.
This may trigger the skin’s inflammatory response. The inflammatory response prompts the transportation of white blood cells and other cells—called macrophages—that engulf the invading organisms.
Protection Against Ultraviolet Rays
Not only does the skin provide a very strong barrier against infections in the body, but it also prevents damage to the body from certain harmful substances, such as ultraviolet (UV) light from the sun (or other sources, such as tanning beds).
How Hair Protects Your SkinOne study found that hair also provides a barrier against both UVB and UVA radiation. The study discovered that the more thickness and density a person’s hair was, the more protective the hair was in providing a better barrier against UV radiation.
How Hair Protects Your Skin
One study found that hair also provides a barrier against both UVB and UVA radiation. The study discovered that the more thickness and density a person’s hair was, the more protective the hair was in providing a better barrier against UV radiation.
Maintenance of Body Temperature
One of the most important functions of the skin is to help maintain the body’s core temperature.
The center in the brain that helps regulate temperature—called the hypothalamus—prompts skin changes in response to a change in the body’s internal temperature.
Thevast blood supply in the skin can help regulate temperature; as the blood vessels dilate, it allows for heat loss. When the vessels constrict, heat is retained. This process lends itself to the regulation of the body’s core temperature.
Sensory Nerves
Sensory nerves are abundant in the top layer of the skin (the epidermis); these nerves transmit feelings of:
Sign of Malfunctioning Sensory NervesWhen sensory nerves in the skin malfunction, the result is often a tingling feeling or a burning sensation.
Sign of Malfunctioning Sensory Nerves
When sensory nerves in the skin malfunction, the result is often a tingling feeling or a burning sensation.
The dermis contains nerve endings and an array of touch receptors. This allows the dermis to detect sensations such as pressure, heat, cold, and contact.
Metabolism
Skin metabolism is the rate at which new skin cells turn over; this occurs between the epidermal and dermal cells that work together to regulate collagen production and repair UV light damage, aging, and other damage caused to the skin.
Secretion
The skin is responsible for excreting various substances, including:
Absorption
The skin has been found to absorb many substances.
The skin also stores some substances, including:
How Does it Work With Other Systems?
The integumentary system is very active in working with other organ systems to maintain the body’s overall balance (called homeostasis). Examples of how the skin helps each body system maintain homeostasis include:
Immune System
The skin interacts with the body’s immune system in many ways to protect the body from infection, serving as a physical barrier to disease-causing microorganisms.
Digestive System
The skin synthesizes vitamin D (from exposure to the sun) therefore providing this vital nutrient to the digestive system. Vitamin D is required to absorb calcium and the skin works with the digestive system to ensure that calcium can be properly absorbed.
Cardiovascular System
Nervous System
Musculoskeletal System
Vitamin D synthesis—which takes place in the skin—promotes calcium absorption. Calcium is needed for the growth and maintenance of bones, as well as for muscle contractions.
Endocrine System
Respiratory System
The smallhairs in the nose(which are part of the integumentary system) act as a filter to remove harmful particles which may otherwise be inhaled into the lungs.
Urinary System
The skin functions to excrete waste products (such as salts and some nitrogenous wastes) into the sweat; this helps the kidneys maintain the body’s proper balance of electrolytes as well as maintaining the normal pH balance.
What Conditions Affect the Integumentary System?
Skin Disorders
Nail Disorders
Hair Disorders
Gland Disorders
Medical conditions can affect any of the four gland types in the integumentary system. Some of these conditions include:
Summary
The integumentary system is the outermost layer of your body. It includes the skin, hair, nails, glands, and sensory nerves. Its function is to provide a barrier to infection and protect the body from temperature changes and potentially harmful external substances.
The integumentary system works together with the body’s other systems to maintain homeostasis. Like other body systems, there are certain conditions that can affect the integumentary system, such as skin disorders, autoimmune conditions, and certain cancers.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Anatomy of the skin.Kim JY, Dao H.Physiology, integument. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2024.Duke University. The Pharmacology Education Partnership.Content background: The anatomy and composition of hair.Khan YS, Fakoya AO, Sajjad H.Anatomy, thorax, mammary gland. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2023.Oregon State University.Functions of the integumentary system.de Gálvez MV, Aguilera J, Bernabó J-L, Sánchez-Roldán C, Herrera-Ceballos E.Human hair as a natural sun protection agent: a quantitative study.Photochem Photobiol. 2015;91(4):966-970. doi:10.1111/php.12433Blair MJ, Jones JD, Woessner AE, Quinn KP.Skin structure–function relationships and the wound healing response to intrinsic aging.Adv Wound Care (New Rochelle). 2019;9(3):127-143. doi:10.1089/wound.2019.1021Brown HS, Bishop DR, Rowan CA.The role of skin absorption as a route of exposure for volatile organic compounds (VOCs) in drinking water.Am J Public Health. 1984;74(5):479-484. doi:10.2105/ajph.74.5.479University of Washington.How the nervous system interacts with other body systems.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Anatomy of the skin.Kim JY, Dao H.Physiology, integument. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2024.Duke University. The Pharmacology Education Partnership.Content background: The anatomy and composition of hair.Khan YS, Fakoya AO, Sajjad H.Anatomy, thorax, mammary gland. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2023.Oregon State University.Functions of the integumentary system.de Gálvez MV, Aguilera J, Bernabó J-L, Sánchez-Roldán C, Herrera-Ceballos E.Human hair as a natural sun protection agent: a quantitative study.Photochem Photobiol. 2015;91(4):966-970. doi:10.1111/php.12433Blair MJ, Jones JD, Woessner AE, Quinn KP.Skin structure–function relationships and the wound healing response to intrinsic aging.Adv Wound Care (New Rochelle). 2019;9(3):127-143. doi:10.1089/wound.2019.1021Brown HS, Bishop DR, Rowan CA.The role of skin absorption as a route of exposure for volatile organic compounds (VOCs) in drinking water.Am J Public Health. 1984;74(5):479-484. doi:10.2105/ajph.74.5.479University of Washington.How the nervous system interacts with other body systems.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Cancer Institute.Anatomy of the skin.Kim JY, Dao H.Physiology, integument. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2024.Duke University. The Pharmacology Education Partnership.Content background: The anatomy and composition of hair.Khan YS, Fakoya AO, Sajjad H.Anatomy, thorax, mammary gland. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2023.Oregon State University.Functions of the integumentary system.de Gálvez MV, Aguilera J, Bernabó J-L, Sánchez-Roldán C, Herrera-Ceballos E.Human hair as a natural sun protection agent: a quantitative study.Photochem Photobiol. 2015;91(4):966-970. doi:10.1111/php.12433Blair MJ, Jones JD, Woessner AE, Quinn KP.Skin structure–function relationships and the wound healing response to intrinsic aging.Adv Wound Care (New Rochelle). 2019;9(3):127-143. doi:10.1089/wound.2019.1021Brown HS, Bishop DR, Rowan CA.The role of skin absorption as a route of exposure for volatile organic compounds (VOCs) in drinking water.Am J Public Health. 1984;74(5):479-484. doi:10.2105/ajph.74.5.479University of Washington.How the nervous system interacts with other body systems.
National Cancer Institute.Anatomy of the skin.
Kim JY, Dao H.Physiology, integument. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2024.
Duke University. The Pharmacology Education Partnership.Content background: The anatomy and composition of hair.
Khan YS, Fakoya AO, Sajjad H.Anatomy, thorax, mammary gland. In:StatPearls. Treasure Island (FL): StatPearls Publishing; 2023.
Oregon State University.Functions of the integumentary system.
de Gálvez MV, Aguilera J, Bernabó J-L, Sánchez-Roldán C, Herrera-Ceballos E.Human hair as a natural sun protection agent: a quantitative study.Photochem Photobiol. 2015;91(4):966-970. doi:10.1111/php.12433
Blair MJ, Jones JD, Woessner AE, Quinn KP.Skin structure–function relationships and the wound healing response to intrinsic aging.Adv Wound Care (New Rochelle). 2019;9(3):127-143. doi:10.1089/wound.2019.1021
Brown HS, Bishop DR, Rowan CA.The role of skin absorption as a route of exposure for volatile organic compounds (VOCs) in drinking water.Am J Public Health. 1984;74(5):479-484. doi:10.2105/ajph.74.5.479
University of Washington.How the nervous system interacts with other body systems.
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