Human Body Systems for Kids: A Poster-by-Poster Guide

Children are fascinated by what is going on inside them. Ask a room of six year olds where their heart is and every hand goes to the chest. Ask what it does and you will hear "it beats," "it loves," and occasionally "it makes blood," which is a great place to start a lesson.

This guide takes the body one system at a time, the way our human body posters do: what each part does in a sentence a child can repeat, one hands-on activity for each, and which poster set suits which age. Every fact comes from Nemours KidsHealth's medically reviewed pages for kids.

How should kids learn the human body?

As a team, one player at a time. Each system gets one job in one sentence, then you show how the jobs connect.

That is the structure of the Human Body Posters Complete Set of 13. It opens with an overview poster, The Human Body, then gives each organ or system its own chart with the same layout every time: what it is, its main parts, how it works, why it matters, how to keep it healthy and a few fun facts. It closes with How It All Works Together, which ties the twelve jobs into one picture.

The repeating layout helps more than you might expect. Once a child has read the heart poster, they know where to look on the lungs poster. That leaves their attention for the new content instead of the format, which is the same reason a good worksheet looks the same every week.

Each poster is 8.5 by 11 inches, laminated and dry-erase, so children can label, circle and quiz directly on the chart and wipe it clean.

What does the brain and nervous system do?

It is the control center. It sends messages that let you think, feel, remember and move.

KidsHealth's guide to your brain and nervous system introduces the brain as a team of parts and starts with the biggest, the cerebrum. It is the thinking part of the brain, it controls the muscles you move on purpose, and it is where your memory lives, both what you ate last night and the name of a roller coaster from two summers ago. You need it to kick a ball, solve a math problem or draw a picture.

Try it: a "message relay." Children stand in a line holding hands. The child at one end is the brain and squeezes a hand; the squeeze passes down the line to the child at the far end, who is the hand that catches a ball. The faster the squeeze travels, the faster the catch. It is a simple way to show what nerves do.

The Brain and The Nervous System are separate posters in the set, so you can teach the boss and the wiring on different days.

What do the heart and blood do?

The heart is a muscle that pumps blood all around your body, and the blood carries oxygen and food to every part.

KidsHealth's page on your heart and circulatory system gives children two facts they can test on themselves. The heart sits a little to the left of the middle of the chest and is about the size of your fist. And at rest, most children will count between 70 and 100 beats a minute.

Try it: take a pulse. Show children how to find the beat at the wrist or neck, count for a minute with a clock, then jump in place for a minute and count again. The number goes up, and now you can ask why. A heart beating 100,000 times a day is the fun fact printed on The Heart poster, and older grades can check it themselves from the KidsHealth resting rate: 70 beats a minute times 1,440 minutes comes to just over 100,000.

The Circulatory System poster follows the blood on its path from the heart and back. Note that it is only in the complete set of 13, not in either 6-pack.

What do the lungs do?

They bring fresh oxygen into the body and push out the carbon dioxide the body does not need.

KidsHealth's page on your lungs and respiratory system explains the part children can feel. When you breathe in, a muscle under the lungs called the diaphragm moves down and the rib muscles pull the ribs up and out, so the chest gets bigger and air rushes in. When you breathe out, the diaphragm moves back up and the chest gets smaller, pushing the air out.

Try it: hands on ribs. Children put both hands on the sides of their ribs and take a slow, deep breath, then feel their hands move out and back in. For older children, a balloon in a bottle model shows the same thing.

What do the stomach, skin and kidneys do?

The stomach turns food into fuel, the skin covers and protects you, and the kidneys clean your blood.

These three are less glamorous than the heart and brain, and children often find them more interesting for exactly that reason. The posters give each a nickname that sticks: The Stomach is "your body's food mixer," The Skin is "your body's amazing cover," and The Kidneys are "your body's clean-up crew."

Try it: for the stomach, put a cracker and a little water in a sealed zip bag and let children squash it, which is roughly what stomach muscles do. For the skin, have children look at their fingertips through a magnifying glass. For the kidneys, a coffee filter that catches sand from water makes a good model of filtering.

What do the skeleton and muscles do?

The skeleton holds you up and protects your organs. The muscles pull on the bones to move you.

KidsHealth's page on your bones has the fact every child wants to share: adults have 206 bones, but a baby's body has about 300 at birth, and some of them fuse together as the baby grows. Its page on your muscles adds that you have more than 600 muscles, in three types: skeletal muscles you move on purpose, smooth muscles that work on their own inside organs like the stomach, and cardiac muscle, which is only in the heart.

Try it: the bicep test. Children put one hand on their upper arm and bend and straighten the elbow, feeling the muscle bunch up and relax. Then ask: which bone is the muscle pulling? The Skeleton poster has the answer, and its dry-erase surface is good for labelling bones from memory.

What does the immune system do?

It is the body's protector team, fighting germs to keep you from getting sick.

The Immune System poster introduces white blood cells as the team that finds and fights germs, and its "keep it healthy" panel goes straight to the habits children control: washing hands, sleeping well, eating healthy food and staying active. That is the link to the rest of the classroom. The Germ Awareness chart above the sink is the immune system lesson in action.

Try it: glitter germs. Put a pinch of glitter on one child's hands, have them shake hands around a circle, and see how far the "germs" travel. Then wash it off with soap and water and talk about why soap works better than a rinse.

How do all the systems work together?

Like a team, where every part has a job and none of them works alone.

The How It All Works Together poster is the one to finish on. It traces a chain children can follow with a finger: you breathe in oxygen, your heart sends oxygen-rich blood everywhere, food gives your body energy, muscles and bones move you, kidneys remove waste and extra water, and your immune system protects you.

Try it: the body tracing. Lay a child down on a long sheet of butcher paper and trace around them (with permission and a giggle). Then the class cuts out paper organs, a heart, two lungs, a stomach and a brain, and glues each one roughly where it belongs, using the poster as a guide. It is the single most memorable human body activity there is, and it turns the summary poster into something children made themselves.

Which human body poster set should you buy for each grade?

Start small with young children and add systems as they grow. Here is how we would match the sets, based on the posters' design for ages 5 to 9:

The two 6-packs together give you twelve posters, and the complete set adds the thirteenth, The Circulatory System, so if you know you want the full wall, the set of 13 is the better buy. Single posters such as The Skeleton or The Heart fill a gap or start a unit on one system.

For more on matching wall displays to ages, see our guide to classroom posters by grade level.

How do you set up a human body wall at home or in class?

In a classroom, all thirteen in three rows; at home, one row of six at the table.

In a classroom, the complete set hangs well in the order of the reference photo: the overview and big organs on top, the supporting systems below, and How It All Works Together at the end of the last row, so the wall reads like the unit. Keep a cup of dry-erase markers on a ledge beneath it, and pick one poster a week to quiz on.

In a homeschool room, the six-poster set fits in a single row above the table, low enough that a child can reach it with a marker. Swap in the systems set when you move on.

For older students, the binder page belongs in a science binder rather than on the wall: organs on the front, skeleton on the back, three-hole punched and laminated so it survives the year. Our homeschool binder setup guide covers how one reference page per subject keeps a binder useful for years, and for a whole grade level, the 10-pack of reference pages gives every student their own. If you are buying for several classrooms, see our guide to buying classroom posters in bulk.

Browse every human body poster, plus animal, dinosaur and periodic table charts, in our science collection.