The three important jobs of the skin

The skin plays three very important roles for us:

1. It protects us by keeping dirt out and all our important fluids inside. 

2. It allows us to touch. The skin is covered with thousands of receptor cells which send information to the brain about what we are touching, letting us know if objects are rough, sharp, smooth or soft.

3. It regulates our temperature cooling us down when we’re hot and warming us up when we’re cold.

Layers of the skin

The skin is made up of three main layers: the epidermis, the dermis and subcutaneous fat. Each one has different things inside.

Epidermis - this is the top layer of the skin. In some areas of the body, it’s very thin like on the eyelids and in other parts like the soles of the feet, it’s thick. This is where new skin cells and melanin are made. Melanin is what protects us from the rays of the sun and it’s also what gives our skin colour. People with darker skin have more melanin. Melanin also causes freckles.

Dermis - this is the layer under the epidermis, it is thicker than the epidermis and contains nerves, blood vessels, oil glands and sweat glands. Here’s what each one does:

The nerves send messages to the brain about different things we feel through the skin. 

The blood vessels bring oxygen and nutrients to the cells in the skin and remove waste.

Oil glands/sebaceous glands make a special oil called sebum which makes our skin waterproof, stops it from getting dry and makes the hairs of the skin shiny. It acts as a natural moisturiser.

Sweat glands produce sweat to cool down the body’s temperature.

Subcutaneous fat - this is a layer of fat that keeps us warm and gives us some padding so we don’t hurt ourselves too badly when we get knocked and bumped. This is the layer under the dermis where the hairs of the body have their roots. Each hair grows out of a little tube called a follicle.

Bye bye skin cells

New skin cells are constantly forming at the bottom of the epidermis. When they’re ready they move towards the top of the epidermis, it takes them around 2 weeks to 1 month to make this journey. 

The old cells that were sitting on the top of the epidermis die, fall off and are replaced with these new cells. So the skin we see on our hands and bodies is really just old skin cells. It doesn’t sound very nice, but these old cells do a great job of protecting us because they are strong and tough. Every minute we lose around 30,000 - 40,000 of these dead skin cells, imagine how many new ones our skin makes every day! The skin is an amazing organ.

Fun facts

• When we get older we have less elastic fibres in the skin and less collagen protein, we also have less fat in the skin. This makes our skin look wrinkly.
• Hair follicles are all over our skin except on the lips, palms and soles of the feet.

• If you spend too much time in the water the skin goes wrinkly because the dead skin cells on the surface of the skin absorb more water, as the skin absorbs water it stretches.
• When we go out in the sun our cells make more melanin to protect us from getting burned, that’s how we get tanned.
• Areas of the skin that are constantly rubbed or pressed get tougher skin, it’s called a callus. They tend to appear on the fingers we use to write with.