Skin
The skin is the largest organ in the human body, taking up 12%-15% of your total body weight. With a total surface area of 1-2m2, the skin has an average weight of 4kg(9lb). It's thickness varies from 1/50in(.5mm) on your eyelids to 1/5in(5mm) on the soles of your feet.
Your skin keeps in salts, soft tissues and body fluids (gross!) and keeps out yucky things like dirt, water, germs and harmful rays from the sun. It protects the inner parts of your body from physical damage and extreme temperatures. It also prevents any tearing of the organs.
There are two layers of the skin; the dermis(under) and the epidermis(over). The epidermis itself contains three layers. The layer at the bottom is called the basal cell layer. After this layer is the prickle cell layer, the granular layer, the clear layer, and then the cornified layer(respectively). The basal layer creates new epidermal cells, then sends them up, toward the cornified layer. The prickle cell layer link together neighbouring cells. In the granular layer cells are flattened and are turned into granules of keratin, which is a rough protein. This is then pushed through the second layer, the clear layer. The clear layer is a thick skin that is more evident in your palms and soles. Finally, the cells have reached the cornified layer. This layer is made up of dead cells that peel off and are constantly replaced.
FUN FACT: If your skin is damp and you scratch at it, you may find that you are scratching off your skin cells! (ew!)
IN YOUR SKIN
The sweat glands in your skin keep it at a constant temperature of about 37 degrees Celsius.
Your sense of touch is provided by the meissner's corpsucle. Free nerve endings below your dermis identify pain, heat and cold. The pacinian corpuscle detects pressure and vibrations.
Your skin is coloured by melanin. The greater the amount, the darker your skin.
Your skin keeps in salts, soft tissues and body fluids (gross!) and keeps out yucky things like dirt, water, germs and harmful rays from the sun. It protects the inner parts of your body from physical damage and extreme temperatures. It also prevents any tearing of the organs.
There are two layers of the skin; the dermis(under) and the epidermis(over). The epidermis itself contains three layers. The layer at the bottom is called the basal cell layer. After this layer is the prickle cell layer, the granular layer, the clear layer, and then the cornified layer(respectively). The basal layer creates new epidermal cells, then sends them up, toward the cornified layer. The prickle cell layer link together neighbouring cells. In the granular layer cells are flattened and are turned into granules of keratin, which is a rough protein. This is then pushed through the second layer, the clear layer. The clear layer is a thick skin that is more evident in your palms and soles. Finally, the cells have reached the cornified layer. This layer is made up of dead cells that peel off and are constantly replaced.
FUN FACT: If your skin is damp and you scratch at it, you may find that you are scratching off your skin cells! (ew!)
IN YOUR SKIN
The sweat glands in your skin keep it at a constant temperature of about 37 degrees Celsius.
Your sense of touch is provided by the meissner's corpsucle. Free nerve endings below your dermis identify pain, heat and cold. The pacinian corpuscle detects pressure and vibrations.
Your skin is coloured by melanin. The greater the amount, the darker your skin.