Anatomy And Physiology

Integumentary System

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The integumentary system includes the skin, hair, nails, and glands of the body. The skin serves many important purposes including protecting the body against infection, gathering sensory information, maintaining a regular body temperature, and keeps the body from drying out (dehydration).

     The skin is made up of two layers, including the dermis and the epidermis. Underneath the dermis, the subcutaneous (aka superficial fascia or hypodermis) layer connects the skin to the muscles throughout your body.


     The epidermis is the outer layer of skin that we can see. Since this layer of skin has no blood vessels and is fed necessary nutrients by capillaries that are located in the dermis. This layer is composed of epithelial cells, including germinativum and stratum basale cells, which multiply and push new cells to the surface as the old ones dye and shed off.


     The dermis (aka the “true skin”) consists of many blood vessels and nerves, and is where the hair, sweat, and oil glands are found. The dermal papillae are found in the dermis and go into the epidermis. Their purpose is to allow blood vessels to supply necessary elements to the epidermis. The dermal papillae are also very useful for identifying people. These are what give each person a unique fingerprint.

Subcutaneous Layer:

     The subcutaneous layer (aka hypodermis or superficial fascia) is located below the dermis and serves the main purpose of connecting the muscles to the skin. This layer is made up of adipose tissue (fat) and loose connective tissue. The loose connective tissue connects the subcutaneous layer with the dermis and the adipose tissue serves as an insulator and an energy supply reserve. Many nerve endings and nerves are located in the subcutaneous layer and allow nerve impulses to be sent from the dermis and epidermis.

Structures of the skin:

Hair covers almost the entire body. The only places that are not covered are: the lips, soles of feet, nipples, palms of hands, and parts of the external genitalia. Hair is developed from living cells that are found in the base of a hair follicle. Melanin is produced from melanocytes that are found in the hair follicle, and is responsible for giving hair its color. Muscles called arrector pili are attached to most of the hair follicles. These muscles contract and push down on the sebaceous glands, which cause sebum to be released in order to lubricate the skin. Contraction of these muscles is also what causes “goose bumps.”

Sebaceous Glands (Oil Glands) have the main purpose of secreting sebum to keep the hair and skin lubricated. These glands are very important in keeping the exterior of our bodies moisturized and looking good, but they also have affects on us that many people hate. The sebaceous glands are the cause of blackheads and pimples. Blackheads form when keratin and dried sebum gather at the openings of the sebaceous glands, which in turn will turn into pimples if it gets infected.

Sudoriferous Glands (Sweat Glands) are found in the subcutaneous and dermal layers. These glands are responsible for keeping the body cooled and eliminating a small amount of waste from the body by releasing sweat. When sweat is released, it is evaporated at the skin’s surface, causing heat to be drawn from the skin. Nails form due to continuous forming of cells the root of the nail. They serve the main purposes of allowing us to grab small objects and to protect toes and fingers. Nails can also be used as a “red-flagger” of many chronic diseases. Changes in their thickness, coloring, and shape could be an indicator of malnutrition, heart disease, anemia, and many other conditions.

As you have read, the skin is a vital organ that serves many purposes. It is important to take care of our skin in order to remain healthy. Good nutrition and cleanliness are necessary to keep skin healthy by eliminating the growth of bacteria and reducing risk of spreading diseases. Another important part of maintaining the skin is preventing skin damage caused by too much exposure to sunlight. Too much sun can cause skin cancer and premature aging. This can simply be done by applying sunscreen when you know that you may be spending a long period of time outdoors.

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