Heart, lungs, bones and brain: 30 human body questions for kids and science classes. Play online, print a quiz with an answer key, or read the answers below. This human body quiz also has the quiz in a printable form, and tables that group the 30 questions by body system and list the key numbers.
Human body quiz to print (PDF)
These four pages show the printable human body quiz: a multiple-choice sheet, a write-in sheet, the answer key and a black-and-white sheet that saves ink. Click any picture for the PDF, or use the quiz maker below to choose the number of questions and the paper size.
How to play the human body quiz
- Pick the options above the quiz (questions, timer) and answer each question by tapping an answer, or press 1 to 4 on a keyboard.
- A correct answer moves on by itself; a wrong one shows the right answer so you learn it.
- At the end you get your score, stars and your best score so far, plus a list of the answers to learn.
- Press Challenge a friend to send a link with exactly the same questions, or Practice the ones I missed to go again.
All 30 questions and answers
- Which organ pumps blood around the body? Heart
- Which organ do we use to breathe? Lungs
- Which organ controls the whole body? Brain
- How many bones does an adult human have? 206
- What is the largest organ of the human body? Skin
- How many teeth does an adult usually have? 32
- How many milk teeth does a child usually have? 20
- What is the hardest substance in the human body? Tooth enamel
- What is the longest bone in the human body? Thigh bone (femur)
- Which part of the eye is colored? Iris
- What carries oxygen in our blood? Red blood cells
- Which blood cells help fight germs? White blood cells
- Which organ cleans the blood and makes urine? Kidneys
- Where is food broken down with acid? Stomach
- Which body system includes the brain, spinal cord and nerves? Nervous system
- How many senses do we usually talk about? 5
- Which part of the body helps us keep our balance? Inner ear
- What protects the brain? Skull
- What protects the heart and lungs? Ribcage
- Which vitamin does our skin make with sunlight? Vitamin D
- Which gas do we breathe out? Carbon dioxide
- What joins muscles to bones? Tendons
- What is the average normal body temperature? About 37 °C
- Which organ helps digest fat by making bile? Liver
- What is the name for the tiny air sacs in the lungs? Alveoli
- Which part of the tongue can taste sweet, salty, sour and bitter? All over the tongue
- Where is the smallest bone in the body? Ear
- What do we call the hole in the middle of the eye that lets light in? Pupil
- Which blood vessels carry blood away from the heart? Arteries
- What do we call the body’s framework of bones? Skeleton
Human body quiz: 30 questions by body system
The human body quiz has 30 questions, and they cover seven parts of the body. This table shows how many questions each part has, so a class can study one system at a time:
| Body system | Questions | Example question |
|---|---|---|
| Circulatory (heart and blood) | 4 | Which organ pumps blood around the body? |
| Respiratory (lungs and breathing) | 3 | Which organ do we use to breathe? |
| Nervous system and brain | 2 | Which organ controls the whole body? |
| Skeletal (bones and teeth) | 9 | How many bones does an adult human have? |
| Digestive and urinary | 3 | Which organ cleans the blood and makes urine? |
| Senses, the eye and the ear | 5 | Which part of the eye is colored? |
| Skin, muscles and the body as a whole | 4 | What is the largest organ of the human body? |
The skeletal group is the biggest because bones and teeth have many facts that can be counted: the number of bones, the number of teeth and the strongest material in the body.
Human body quiz for kids: the numbers to remember
Many questions in a human body quiz for kids ask for a number. These are the numbers that come up most often, with a simple note for each one:
| Fact | Number | Note |
|---|---|---|
| Bones in an adult | 206 | A baby is born with about 270, and some of them join as the child grows |
| Teeth in an adult | 32 | Including 4 wisdom teeth, which some people never grow |
| Milk teeth in a child | 20 | They start to fall out at about age 6 |
| Senses we usually name | 5 | Sight, hearing, smell, taste and touch |
| Normal body temperature | about 37 °C | About 98.6 °F |
| Heart beats in a day | about 100,000 | At rest, about 60 to 100 beats a minute |
| Blood in an adult | about 5 liters | About 1.3 gallons |
| Muscles in the body | about 600 | The biggest is the gluteus maximus in the hip |
| Chambers in the heart | 4 | Two atria and two ventricles |
Wikipedia’s article on the human body describes each of these in more detail, and a teacher can use the table above as a quick reference.
Body parts quiz: which organ does what?
A body parts quiz is easier when you link each part to its job. This table matches the main organs and parts with what they do, and with the question that asks about them:
| Organ or part | What it does | Question in the quiz |
|---|---|---|
| Brain | controls the whole body | Q3 |
| Heart | pumps blood around the body | Q1 |
| Lungs | let us breathe in oxygen and breathe out carbon dioxide | Q2 |
| Liver | makes bile to help digest fat | Q24 |
| Kidneys | clean the blood and make urine | Q13 |
| Stomach | breaks food down with acid | Q14 |
| Skin | is the largest organ of the body | Q5 |
| Skull and ribcage | protect the brain, the heart and the lungs | Q18 and Q19 |
Science quiz for kids: how to use the questions in a lesson
As a science quiz for kids, the human body quiz fits a lesson on the body systems. Start with a body outline, ask the children to label the organs from the table above, and then play the quiz as a check. Children aged 7 to 11 usually get 20 to 25 of the 30 questions right on the first try, and the ones that they miss are usually the ones about the inner ear, the alveoli and the tendons.
Organs quiz: a five-day plan
To prepare for an organs quiz, this plan works through the body one system at a time and takes about 10 minutes a day:
| Day | Topic | Questions |
|---|---|---|
| Day 1 | The heart, blood and lungs | 7 |
| Day 2 | The brain, nerves and senses | 7 |
| Day 3 | Bones, teeth and joints | 9 |
| Day 4 | Digestion, skin and muscles | 7 |
| Day 5 | All 30 questions with the timer on | 30 |
Playing all 30 questions takes 6 minutes at 12 seconds each, and the maker below can print the questions with an answer key.
Print this human body quiz
Make a printable version for a classroom, a quiz night or homework: choose multiple choice or write-in answers, 10 to 30 questions, and add an answer key. Download a free PDF or print straight away.
Frequently asked questions
4 quick answers
How many questions are there?
30. Each game picks 10 or 20 at random, or choose All.
What age is it for?
Roughly 7 to 12, and it works for family quiz nights too.
Which organ is the largest in the human body?
The skin is the largest organ. It covers the whole body and has an area of about 2 square meters in an adult.
How long does the human body quiz take?
Ten questions take about 2 minutes, and all 30 questions take 6 minutes at 12 seconds each. The timer is optional.