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Human Body Quiz: Organs, Cells & Body Systems

Test basic human anatomy with 10 free questions about organs, blood, breathing and cells. Get explanations for each answer, with no timer or sign-up.

Medium10 questionsAbout 3 minutesNo timer

How do the heart, kidneys, lungs and nervous system share the work of keeping a body functioning? This human body quiz checks ten foundational ideas about organs, cells and body systems. The questions focus on what structures do, rather than on specialist diagnostic terminology. Read each explanation to connect a part with its role: carrying oxygen, absorbing nutrients, filtering blood or transmitting signals. A short general-knowledge quiz cannot assess your health or replace medical advice; it is a starting point for learning the vocabulary of anatomy and physiology.

Question 1 of 100 correct

Which organ pumps blood around the body?

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Your question-by-question study guide

Prefer to read, or revisit what you learned? Explore every question below. Open an answer when you’re ready.

1. Which organ pumps blood around the body?

  • Pancreas
  • Heart
  • Liver
  • Stomach
Reveal answer and explanation

Heart — The heart's muscular chambers contract to circulate blood through blood vessels.

2. What carries most oxygen in human blood?

  • Hemoglobin
  • Insulin
  • Bile
  • Keratin
Reveal answer and explanation

Hemoglobin — Hemoglobin in red blood cells binds oxygen for transport to tissues.

3. Which organs filter blood to produce urine?

  • Lungs
  • Intestines
  • Adrenal glands
  • Kidneys
Reveal answer and explanation

Kidneys — Kidneys remove wastes and regulate water and electrolyte balance.

4. Which organ forms the body's outer protective covering?

  • Spleen
  • Thyroid
  • Skin
  • Heart
Reveal answer and explanation

Skin — Skin forms the outer covering of the body, providing a barrier and helping with temperature regulation. Its sensory receptors also help detect touch, pressure and temperature.

5. Which bones protect the brain?

  • Pelvic bones
  • Skull bones
  • Ribs
  • Vertebrae in the lower back
Reveal answer and explanation

Skull bones — The cranial bones surround the brain and help protect it from injury.

6. Where does most nutrient absorption take place?

  • Small intestine
  • Esophagus
  • Large intestine
  • Mouth
Reveal answer and explanation

Small intestine — The small intestine's folds and villi provide a large absorptive surface.

7. Which cells transmit signals in the nervous system?

  • Platelets
  • Red blood cells
  • Fat cells
  • Neurons
Reveal answer and explanation

Neurons — Neurons communicate using electrical impulses and chemical signals.

8. Which muscle is especially important for inhaling?

  • Quadriceps
  • Masseter
  • Diaphragm
  • Biceps
Reveal answer and explanation

Diaphragm — The diaphragm contracts and moves downward, expanding the chest cavity.

9. What is the main function of white blood cells?

  • Storing calcium
  • Immune defense
  • Carrying most oxygen
  • Producing bile
Reveal answer and explanation

Immune defense — White blood cells help recognize and respond to infections and other threats.

10. Which part of the eye controls how much light enters through the pupil?

  • Iris
  • Retina
  • Optic nerve
  • Sclera
Reveal answer and explanation

Iris — The iris changes pupil size to regulate the amount of incoming light.

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