Heart Heroes: Fun Circulatory Quiz for Curious Kids!

1. What organ pumps blood through the body?
   1. Kidney
   2. Lungs
   3. Liver
   4. Heart
2. What color is oxygen-rich blood usually shown as?
   1. Dark purple
   2. Blue
   3. Bright red
   4. Yellow
3. Which of the following is a blood vessel: heart, artery, or lung?
   1. Veinless
   2. Heart
   3. Lung
   4. Artery
4. What do red blood cells carry to the body cells?
   1. Oxygen
   2. Carbon dioxide
   3. Glucose
   4. Hormones
5. Who discovered that blood circulates around the body?
   1. Galen
   2. William Harvey
   3. Andreas Vesalius
   4. Marcello Malpighi
6. What happens to your heart rate when you run?
   1. It decreases
   2. It increases
   3. It stays the same
   4. It stops
7. Which organ cleans old blood cells and helps fight germs?
   1. Liver
   2. Spleen
   3. Pancreas
   4. Thyroid
8. In cartoons, what animal is often used to show a brave heart?
   1. Eagle
   2. Lion
   3. Bear
   4. Horse

Answers and explanations

1. Question: What organ pumps blood through the body?
   Answer: Heart
   Explanation: The heart is a muscular organ that pumps blood through the circulatory system, delivering oxygen and nutrients to tissues. Interesting fact: the average adult heart beats about 60–100 times per minute and pumps roughly 5 liters of blood each minute at rest.
2. Question: What color is oxygen-rich blood usually shown as?
   Answer: Bright red
   Explanation: Oxygen-rich blood is usually depicted as bright red because oxygen binding to hemoglobin changes its color to a vivid red; this is why arterial blood looks brighter than venous blood. Fun fact: the red color comes from iron in hemoglobin — oxygenated hemoglobin reflects more red light than deoxygena
3. Question: Which of the following is a blood vessel: heart, artery, or lung?
   Answer: Artery
   Explanation: An artery is a blood vessel that carries blood away from the heart to the body; it usually transports oxygen-rich blood (except for pulmonary arteries). Arteries have thick, muscular walls to withstand high pressure, and studying them is key to understanding circulation and cardiovascular disease.
4. Question: What do red blood cells carry to the body cells?
   Answer: Oxygen
   Explanation: Red blood cells transport oxygen from the lungs to body tissues using hemoglobin, a protein that binds oxygen molecules. Oxygen delivery is vital because cells use it in mitochondrial respiration to produce the energy (ATP) needed for all bodily functions.
5. Question: Who discovered that blood circulates around the body?
   Answer: William Harvey
   Explanation: William Harvey was the 17th-century English physician who first accurately described the systemic circulation of blood and the role of the heart as a pump in his 1628 work De Motu Cordis; this discovery laid the foundation for modern cardiovascular physiology and changed medicine by replacing older,
6. Question: What happens to your heart rate when you run?
   Answer: It increases
   Explanation: During running your sympathetic nervous system raises heart rate to deliver more oxygen and nutrients to muscles; this increase supports higher metabolic demand and improves cardiovascular fitness over time. Interesting fact: regular running can lower resting heart rate by strengthening the heart, a
7. Question: Which organ cleans old blood cells and helps fight germs?
   Answer: Spleen
   Explanation: The spleen filters and removes old or damaged red blood cells and helps mount immune responses by producing and storing white blood cells; it's an important organ for blood maintenance and infection defense. An interesting fact: the spleen also stores a reserve of blood that can be released during a
8. Question: In cartoons, what animal is often used to show a brave heart?
   Answer: Lion
   Explanation: Lions are classic symbols of courage and strength in cartoons and literature—think of the 'lionhearted' archetype. An interesting fact: lions have been used as emblems of bravery in cultures worldwide, from medieval coats of arms to modern storytelling.