Your Skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connect them.

Your teeth are also considered part of your skeletal system but they are not counted as bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance in your body.

How does the Skeletal System help us?

Support
The main job of the skeleton is to provide support for our body. Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without bones you'd be just a puddle of skin and guts on the floor.

Protection Your skeleton also helps protect your internal organs and fragile body tissues. The brain, eyes, heart, lungs and spinal cord are all protected by your skeleton. Your cranium (skull) protects your brain and eyes, the ribs protect your heart and lungs and your vertebrae (spine, backbones) protect your spinal cord. Movement Bones provide the structure for muscles to attach so that our bodies are able to move. Tendons are tough inelastic bands that hold attach muscle to bone.

Who has more bones a baby or an adult?

Babies have more than adults! At birth, you have about 300 bones. As you grow older, small bones join together to make big ones. Adults end up with about 206 bones.

Are bones alive?

Absolutely. Old bones are dead, dry and brittle. But in the body, bones are very much alive. They have their own nerves and blood vessels, and they do various jobs, such as storing body minerals like calcium. Bones are made of a mix of hard stuff that gives them strength and tons of living cells which help them grow and repair themselves.

What is a bone made of? A typical bone has an outer layer of hard or compact bone, which is very strong, dense and tough. Inside this is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. In the middle of some bones is jelly-like bone marrow, where new cells are constantly being produced for the blood. Calcium is an important mineral that bone cells need to stay strong so keep drinking that low-fat milk!

How do bones break and heal?

Bones are tough and usually don't break even when we have some pretty bad falls. I'm sure you have broken a big stick at one time. When you first try to break the stick it bends a bit but with enough force the stick finally snaps. It is the same with your bones. Bones will bend a little, but if you fall the wrong way from some playground equipment or maybe your bike or skateboard you can break a bone. Doctors call a broken bone a fracture. There are many different types of fractures.

Luckily, bones are made of living cells. When a bone is broken your bone will produce lots of new cells to rebuild the bone. These cells cover both ends of the broken part of the bone and close up the break.

How do I keep my bones healthy?

Bones need regular exercise to stay as strong as possible. Walking, jogging, running and other physical activities are important in keeping your bones strong and healthy. Riding your bike, basketball, soccer, gymnastics, baseball, dancing, skateboarding and other activities are all good for your bones. Make sure you wear or use the proper equipment like a helmet, kneepads, shin guards, mats, knee pads, etc... to keep those bones safe.

Strengthen your skeleton by drinking milk and eating other dairy products (like low-fat cheese, frozen yogurt, and ice cream). They all contain calcium, which helps bones harden and become strong.

An x-ray image is produced when a small amount of radiation passes through the body and strikes a sheet of sensitive film placed on the other side of the body. Bone, which contains calcium, does not let much radiation through and results in white images on the x-ray film. Radiologists are doctors who are specialists in reading and making sense of X-rays, and they help other doctors figure out what's going on inside you.

What's up with joints? Your skeleton has over 200 joints. Joints are where bones come together. Ligaments are strong inelastic bands of connective tissue that help hold bones together at joints. Joints allow your body to move in many different ways. Bending, twisting, stretching, running, jumping and skipping are made possible by muscles and joints. In your two wrists and two hands you have about eighty joints. Thanks to these joints, you can tie your shoes, hold a fork, play instruments, video games and many other things. Where the bones come together at joints there is a cushion of cartilage that helps protect the bones. Cartilage helps to prevent the bones from rubbing against each other and wearing down the bone. Between the joints in your spine the vertebrae are protected by cushiony discs made of cartilage. Your nose and ears also are made of cartilage. Try bending your ears and nose but don't get carried away!

Your Skeletal System