The Integumentary System The Integumentary System “The Skin” By: Abby Mullins and Clint Deaton

Skin Skin is the largest organ in your body. Much of the information you receive about your body comes through your skin.

The Three Layers of Tissue. 1.Epidermis- the outer layer, thinnest layer of your skin. 2.Melanin- pigment that protects you skin from the ultra violet (UV) rays in sunlight and gives it color. 3. Dermis- the layer of cells directly below the epidermis.

Epidermis The outermost cells are dead and water-repellent. 1,000’s of epidermal cells rub off when you take a shower, shake hands, blow your nose, and scratch your elbow. Epidermal cells are replaced constantly.

Melanin Melanin gives skin it’s color. Different amounts of melanin produced by new cells result in differences in skin color. When exposed to UV rays, the Melanin production increases and makes skin darker.

Dermis It is thicker than Epidermis contains many blood vessels, nerves, muscles, oil, all sweat glands and other structures. Below the Dermis, is a fatty region that insulates the body where fat is deposited when people gain wait.

Skin Functions -Protection -Sensory Response -Formation of Vitamin D -Regulation of body temp. -Ridding of body waste Protection is the most important

Thermal Energy and Waste Exchange Your skin plays an important role in regulating your body temperature. Blood vessels in the skin can help release or hold thermal energy. If the blood vessels expand, or dilate, blood flow increases. Sweat glands help regulate the body’s temperature excrete waste.

Skin Injuries and Repair Your skin often is bruised, scratched, burned, ripped, and exposed to harsh conditions like cold and dry air. The skin produces new cells in its epidermis and repairs tears in the dermis.

Bruises When you have a bruise, your skin is not broken but the tiny blood vessels underneath the skin have burst. Red blood cells from these broken blood vessels leak into the surrounding tissue. They break down and release a chemical called hemoglobin. As the injury heals, the bruise eventually turns yellow, as the pigment in the red blood cells is broken down even more by the chemical and reenters the bloodstream.

Cuts Any tear in the skin is called a cut. Blood flows out of the cut until a clot forms over it. Cells in the surrounding blood vessels fight infection while skin cells beneath the scab grow to fill the gap in the skin. In time, the scab falls off leaving new skin behind. If the cut is large enough a scar may develop because of the large amounts of thick tissue fibers that form.

Skin Grafts Pieces of skin that are cut from one part of a persons body and then moved to the injured or burned area where there Is no skin are called skin grafts. The skin graft is kept alive by a nearby blood vessels and soon become part of the surrounding skin. Successful skin grafts must be taken from the victims own body, or possible an identical twin.

Weird skin facts An average adult’s skin spans 21 square feet, weighs nine pounds, and contains more than 11 miles of blood vessels. The skin releases as much as three gallons of sweat a day in hot weather.