The Mysterious Human Body

You probably don’t realize it, but as you are reading this your body is doing amazing things! Energy from the food you ate for breakfast is currently powering your brain. Your brain is tracking the screen and telling your hand when to keep scrolling. The muscles in your hand need oxygen to work. Your heart is constantly beating to carry oxygen to your hand and brain, so they can continue working.

Don’t forget about your lungs that collect oxygen, your stomach that had to digest your food, your intestines that absorbed nutrients, and all the other organs in your body that are required just for you to read this sentence!

There’s a lot going on in the human body. Amazingly, all of these tasks happen in tiny little cells. These cells group together into tissues, which build entire organs. Somehow, all of these components come together to make you, well… you!

The study of the human body is called human anatomy. There’s a lot we are still learning about the human body – but what we do know is fascinating!

Human Body

What is a human body made of?

Your body is a collection of trillions of cells – all working together to ensure you stay alive! Each of these cells is smaller than the period on this sentence. Most cells work together as part of an organ. Here are some of the most important organs in your body:


Your brain sends messages to other parts of your body, telling them what to do. Your brain also holds memories and thoughts. Plus, your brain is connected to your eyes, ears, nose, mouth, and other body parts that help you sense the world around you. Your brain processes these signals like a biological computer and tells you everything you need to know to survive.


Your lungs are air sacs that expand and contract like a balloon. Oxygen is transferred through the thin wall of your lungs, directly into your bloodstream. Your cells need this oxygen to help produce energy and keep functioning.


Your heart is a very strong muscle that acts like a pump. It pushes the blood through your circulatory system. The blood cells within your blood pick up oxygen. But, did you know that your blood is also like a trash truck? Every cell in your body is producing waste products as they function, and your blood has to carry these wastes away.


Your kidneys are like the waste disposal factory for your body! Blood moves through the kidneys, and the waste products are turned into urine for excretion.


Your stomach contains acid and enzymes that break down food into smaller pieces. Your stomach also has muscles that make sure the food mixes with the acid and moves along to the small intestines.

Organs are part of Systems

No organ can do its job on its own. Each organ is part of a system. These systems work to perform important functions throughout your body. Here are some examples:

Immune System

The immune system attacks invading cells that might make you sick or cause infections. The cells in the immune system are constantly fighting off invading bacteria and viruses – kind of like your own army.

Circulatory System

The circulatory system moves your blood, from your head down to your toes. Along the way, blood carries oxygen to cells and removes waste products from cells.

Nervous System

The nervous system transmits information to and from your brain. The brain not only processes incoming signals, but it also tells your muscles when to move, gives you a sense of balance, and allows you to make coordinated movements.

Muscular System

The muscular system includes your muscles and bones. Together, your muscles and bones work together to create a moving structure. Bones give your body a rigid framework, while your muscles can pull against bones to create movement.

Digestive System

The digestive system starts in your mouth. Your saliva and teeth begin the digestive process by grinding up food like a blender and starting the process of digestion. In the stomach, strong acids break food down into molecules. By the end of this system, your body has removed all the nutrients it can use from your food. Then, whatever you can’t digest is excreted as feces.

Written by Laura McCamy

Edited by Gabriel Buckley, MS Professional Natural Sciences