Our skin is considered to be the largest ‘organ’ of the body. An ‘organ’ is a group of tissues that work in conjunction to perform a specific function that is required by the body. Other organ examples include the lungs, heart and your brain.
Skin has the amazing ability to perform many functions at the same time. It is a covering that protects our muscles, bones and internal organs from external diseases, while at the same time it reacts to cold and heat, communicating with our brain and also uses our blood to help in regulating the heat of our bodies.
- The skin of mammals have three main layers: the epidermis, the dermis and the sub cutis.
- The epidermis of the skin is the outer layer and is the thickest on the soles of your feet and the palms of your hands. (approximately 1.5 mm thick)
- The sub cutis is also known as the hypodermis and this is the deepest layer of the skin. This is the place that stores fat as well as contains hair follicle roots, nerves and blood vessels.
You might have noticed that when you fall down and cut yourself, the healing process caused a scar. Scar tissue is really made up of the same type of tissue as regular skin, except that it may have a different color and can lack hair or sweat glands.
Human skin comes in different colors and is completely dependent upon how much pigment the skin contains. The pigment is called ‘melanin’. Lighter skinned people have very little melanin while darker skinned people have a higher level of melanin. It is the melanin in the skin that helps to protect against the sun’s ultraviolet light that can damage skin.
The skin has a way of protecting itself when there are repeated pressures or friction in an area. The skin builds up a ‘callus’ so that the area is not damaged.
- Your skin cells live and die and the dead skin cells fall off. Most of the dust that you find in your home is actually dead skin cells.
- Almost all mammals have some form of hair on their skin, although in some cases, it isn’t easy to detect.
- A rhinoceros has skin that is incredibly thick. It is between 1.5 and 5 cm deep.
- When you look at a polar bear you see beautiful white fur. The surprising thing is that their skin is actually black. It is the fur that contains both white and transparent ‘tubes’ that reflect light that makes them look white.
Frogs are amphibians and they have unique qualities to their skin. Frogs don’t drink water but instead, their bodies soak in the water that they need through their skin. It is also used to absorb almost half of the air that they need.
- People look at snakes and think they are oily or slimy. Snake skin is actually dry and smooth.
- In the sea, there are living creatures such as barnacles and sea lice that make their homes by attaching themselves to the skin of whales and other objects.
- We also refer to some vegetables and fruits as having ‘skin’. These are familiar to us as oranges, potatoes, bananas and apples.
- Skin in the animal world has many talents, uses and abilities.