Human Body 1:00

Living Bones Marrow for Kids

1The Secret Factory Inside You

While bones might look like dry, white sticks in a museum, the ones inside your body are buzzing with life! They are actually living organs that grow, heal, and even communicate with the rest of your body. The most exciting part is hidden deep inside: the bone marrow. This soft, jelly-like substance is tucked away in the hollow centers of your bones, protected by a hard outer shell called compact bone. It is a busy workplace that never takes a day off, ensuring your body has everything it needs to keep moving.

2Making Millions of Blood Cells

Think of your bone marrow as a super-fast assembly line. Every single second, it pumps out about 2 million brand-new red blood cells to replace the old ones. These cells are like tiny delivery trucks carrying oxygen to your muscles and brain so you can run and think. But that is not all! The marrow also creates white blood cells, which act like your body's personal security team to fight off germs, and platelets, which are the experts at stopping your cuts from bleeding. Without this constant production, your body would run out of the vital supplies it needs to stay healthy.

3Your Body’s Mineral Bank

Bones also act as a high-security vault for important minerals. They store about 99% of your body’s calcium and 85% of its phosphorus. These minerals are what make your bones and teeth rock-hard, but your heart and nerves need them to work properly too. If your blood is running low on these minerals, your body "withdraws" them from your bone bank. This is why eating healthy foods and drinking milk is so important—it keeps your living bone bank full and your marrow factory running at full speed!

Video Transcript

Introduction

When you think of bones, you might picture hard, solid sticks. But your bones are very much alive and constantly changing! Inside many of your bones is something amazing called bone marrow. It is a soft, spongy substance that works like a tiny factory, making all the different kinds of blood cells your body needs every single day.

Key Facts

Did you know that bone marrow produces millions of new red blood cells every second? These cells carry oxygen all around your body! Also, bones are not just for support; they store important minerals like calcium and phosphorus, releasing them when your body needs them.

Think About It

Why is it so important that your bones have marrow inside them, and what would happen if they did not?

The Answer

Bone marrow is incredibly important because it is where your body makes all your blood cells, including red cells that carry oxygen, white cells that fight germs, and platelets that help stop bleeding. Without marrow, your body could not make new blood, and you would become very sick.

Frequently Asked Questions

What exactly is bone marrow?

Bone marrow is a soft, spongy tissue found inside the center of most bones. It acts as a factory that produces all of your body's blood cells, including those that carry oxygen and those that fight infections. It is so important that your body protects it inside the hardest parts of your skeleton.

How many blood cells does bone marrow make?

It is incredibly fast! Your bone marrow produces about 2 million red blood cells every single second. Over a whole day, that adds up to billions of new cells that keep your blood fresh and your energy high.

Are all bones filled with marrow?

Most of your bones contain marrow, but the most active 'factories' are in your larger bones. This includes your hip bones, ribs, breastbone, and the ends of your long arm and leg bones. As you grow older, some of the red marrow in your long bones turns into yellow marrow, which is used to store fat for energy.

What happens if our bone marrow stops working?

If the marrow factory stops, your body cannot make new blood cells. This means you wouldn't have enough oxygen being delivered to your organs, and your immune system wouldn't be able to fight off simple colds or germs. Thankfully, your bones are very good at keeping the marrow safe and healthy!

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