The Integumentary System

http://www.uchospitals.edu/online-library/content=CDR258035

        Ahhh skin, what would we do without it? The truth is, we wouldn't survive without our skin.  Our skin is what makes up our integumentary system. The integumentary system does many things for the good of our body. It protects the body's internal living tissues and organs, protects against invasion by infectious organisms, retains water to prevent dehydration, protects the body against temperature change, helps dispose of waste materials, is a receptor for touch, pressure, pain, heat, and coldness, and it stores water and fat. All of these functions are vital for us to survive and maintain homeostasis within the body.

       One thing you might notice about your skin that is different than other organs (yes it is an organ) is its elasticity and its ability to stretch constantly. This is important so we can maintain a barrier between our body and the outside world and still be able to move our joints and flex our muscles without the skin breaking. The skins rich network of elastic and collagen fibers is what makes it so flexible. 

       The skin is not very thick. you may know this from when you get a cut. You obviously don't have to cut very deep to see the blood from the capillaries below start to come to the surface. But the skin being thin has its advantages.  The skin is perfect for things like absorption and secretion. You may notice that sweat and oils are secreted from the skin. You might also see that your skin absorbs things.  If some medicines are applied topically on the skin, it can be absorbed into the blood stream. However keep in mind that the skin is selectively permeable. Keratin keeps water from being absorbed through direct contact. So basically if you go swimming keratin is the reason your cells don't explode. 

http://www.redefiningthefaceofbeauty.com/2013/04/are-you-suffering-from-extreme-sweating.html

       Your skin can do extraordinary things. One thing it does for us is help maintain a good homeostatic balance in our bodies.  When your body gets hot, you sweat. When your skin gets cold it sends messages to the hypothalamus to tell the body to shiver or trigger constriction.  Our skin is also a great way to contact our outside environment by using nerve receptors in the skin to sense pressure, pain, and heat. These things also help us voluntarily react to the environment around us.  The integument system is truly amazing in the way it works in our body to complete several tasks.