Lucy Beevor - Understanding Our Head

Did you know that skin is also an ? In fact, it is the biggest organ in your body.

Take a closer look at the skin on your face. Can you find a spot that isnt covered in hair? Your cheeks? Guess again. Fine hair covers most of your skin, even your cheeks. Skin is pierced by thousands of tubes called hair follicles. Your scalp alone has about 100,000 hair follicles. Your hair may be curly, straight, black, brown, blond, or red. But no matter what it looks like, hair keeps your head and body warm and protected.

Did you know that curly hair grows from oval-shaped follicles? Straight hair grows from circular follicles.

We wouldnt be able to see the world around us without our eyes. When you look at something, what you are actually seeing is light bouncing off that object. Your eyes then turn these light rays into images your brain can understand.

Light travels on an amazing journey through your eyes. First, eyes focus the light. Next, they take a picture, sort of like a camera does. Then they then send information about the picture to your brain.

There are six muscles that attach to your eye. These muscles move your eyes around, up and down, and side to side.

Like your eyes, your ears are also part of an amazing journey. When you hear a sound, youre hearing sound waves. The sound waves are collected by your outer ear and sent through the ear canal. In the middle ear, sound waves vibrate the brain.

The stirrup in the inner ear is the smallest bone in the body. It measures roughly 0.12 0.1 inch (3 2.5 millimeters).

Whats in a Name?

The stirrup bones proper name is the stapes. It gets its nickname because it looks like a tiny stirrup, the metal loop attached to a horses saddle that holds a riders foot.

The Mouth: A Multitasker

For a peek inside the human head, all you have to do is open your mouth. Youll see your tongue and teeth. But its the parts you cant see that make the mouths work possible.

The human tongue has eight muscles. The muscles move our tongues, which helps us to speak.

tongue. Saliva makes it easier to chew food and to speak. Just think of how hard it is to talk when your mouth is dry.

Sense of Taste

Hidden in the little bumps on your tongue are about 10,000 taste buds. These tiny organs respond to tastes such as sweet, salty, sour, and bitter. Taste buds send messages to the brain about how something tastes. But taste buds only respond to liquid. Dry food in a mouth with no saliva would have no taste at all. Even if you were to place a piece of lemon on a dry tongue, you would not be able to taste that it is sour.

See for Yourself

Look in a mirror and stick out your tongue. Do you see the red bumps on your tongue? They are papillae. Inside the papillae are thousands of taste buds. Amazingly, taste buds are replaced every two weeks.

Body Talk

Like your on the inside of your mouth is strong. It can stand a lot of wear and tear, such as when you bite the inside of your cheek.

The Nose: A Gatekeeper

You can also look inside your brain about the way a spicy food or a loaf of bread smells.

Our noses help us to taste food by sending smell signals to the brain when we eat.

The nose also plays an important role in keeping us safe. It alerts us to dangerous smells, such as smoke, gas, or food that has gone bad.

See for Yourself

As you eat your lunch, try holding your nostrils closed. Can you still taste the food in your mouth? Even though your mouth is working hard to chew the food, you cant taste it. This is because the nose and the mouth work as a team to help us taste what we eat.

Body Talk

Humans can recognize about 10,000 smells.

Yet 95 percent of the nose plays no role in smelling. Your noses biggest job is to filter the air you breathe. The nose traps dust and bacteria in slimy . You swallow the mucus to keep the dust and bacteria away from your lungs. Even when we breathe through our mouths, our nose is taking in air. In fact, humans mostly breathe through their noses.

THE NEXT LAYER

Just beneath the skin on your face, there are lots of body parts you couldnt do without. Smiling and talking would be impossible without them. The muscles and bones in our heads are always busy.

Muscles make up around half of a humans bodyweight.

The Constant Work of Muscle

The human face is constantly moving, from blinking and winking to speaking and chewing. If you could look through your skin, you would see the stretchy muscles that make this movement possible. Muscles can only pull a bone. They cant push. Muscles work in pairs so you can move a body part in more than one direction.