Your skeletal system is to your body what wood and bricks are to a house. With a strong foundation, your body is designed to do a multitude of amazing tasks, from running to giving birth.

Learn about the skeletal system and some unique trivia you might never have known about the bones, cartilage, and ligaments that make up your skeletal system.

1. Your skeleton is made of more than 200 bones

Inside your body are bones. Each bone plays a very important role in making all the mechanics of your body function properly. If a bone is broken, all the bones around it can’t perform their duty properly.

2. The body has two types of bone

You may think of bone as a hard, dense material, but only one type of bone is like this. This dense, hard bone is called cortical bone. Cortical bones are primarily the “structure” bones.

The second type, trabecular bone, is soft and spongy. It’s often found inside large bones and in your pelvis, ribs, and skull. Though it’s less dense than cortical bone, it’s still quite hard and protective.

3. Bones are filled with a spongy tissue

Bone marrow is a spongy substance that’s found inside large bones like your hips, pelvis, and femur. Bone marrow houses stem cells. Stem cells are responsible for producing many of your body’s most important cells, including blood, brain, heart, and bone cells.

4. Babies are born with 300 bones

Adults will end up with only 206 bones, but babies are born with . It’s not that bones disappear as we grow older. Instead, these tiny bones fuse together to form the larger bones of the skeletal system.

5. The smallest bone in the body is in your ear

The stapes, a bone in your inner ear, is the of all your bones. This bone is also sometimes called the stirrup because of its Y shape. Together with the anvil and hammer bones, the stapes helps translate sounds you hear into waves your brain can understand.

6. The longest bone in the body is in your leg

The femur, which runs from your hip to your knee, is the longest and largest bone in your body. It’s also the strongest. Just think of all the weight that bone handles in a day. No wonder it’s so strong!

7. Bones are designed to take a beating

Yes, bones can break. But they’re designed to stand up to daily wear and tear. For example, some bones must be able to absorb your body weight in force. They must also be resilient. You take steps per year, so bones are built to take the constant use.

8. More than half your bones are in your hands and feet

You have 206 bones in total, and of them are in your hands and feet.

9. One bone isn’t connected to any other bones

The hyoid bone, which is in your throat, is the only bone that doesn’t connect to a joint. The hyoid is responsible for holding your tongue in place.

10. Most people have 12 ribs, but some have 13

A 13th rib is rare — only of people are born with it. In most people, this extra rib, called a cervical rib, can cause medical issues like neck pain. For that reason, people born with this extra rib often have it removed.

11. The biggest joint in your body is your knee

At the knee joint, three bones connect: your femur, tibia, and patella. Those three large bones require an equally large joint to connect them. That’s why your knee is the largest joint in your body.

12. A skeletal system isn’t that common in the world

Humans are part of a group of creatures called vertebrates. That means our bones are covered by a system of tissue and skin. Only 10 percent of the world’s animals (humans included) are vertebrates.

The other are invertebrates. Their bones are on the outside of their body.

13. Bones are strong, but teeth are stronger

The enamel on your teeth, which are considered part of your skeletal system, is actually than bones. Enamel protects the delicate nerves and tissue inside your teeth. Inch for inch, your teeth can take more wear and tear than any of your other bones.

14. Bones are natural healers

When you fracture a bone, your body will go to work producing new bone cells and helping heal the break. A cast or brace just ensures the bone heals straight so you don’t have more problems in the future.

15. You can eat your way to stronger bones

Bones lose strength over time. Keeping them strong requires eating calcium-rich foods like dairy products, broccoli, and some fish. Exercise, especially weight-bearing exercise, helps keep bones strong, too.

The skeletal system can support you for a lifetime of movement. Taking proper care of it ensures you can move longer, experience more, and have greater health. Knowing how to properly care for your bones can go a long way to a healthy, fulfilling life.