Year 6 Science: The heart as a pump
Part of the Year 6 Science the circulatory system and transport chapter. Chapter overview · whole chapter on one page
The heart as a pump
The circulatory system is made of the heart, the blood vessels and the blood. Together they carry substances around the body.
The heart is a muscle that pumps blood. It has four chambers. The two upper chambers are called atria, and they receive blood. The two lower chambers are called ventricles, and they pump blood out.
Blood is pumped in a loop. The heart sends blood to the lungs to pick up oxygen. The oxygen-rich blood returns to the heart, and the heart pumps it to the body. Blood from the body returns to the heart, and the loop starts again.
Key ideas
- The heart is a muscular pump with four chambers.
- The two upper chambers are atria, which receive blood.
- The two lower chambers are ventricles, which pump blood out.
- Blood travels from the heart to the lungs, then back to the heart, then to the body.
Method. Count the chambers in the diagram of the heart.
- Count the upper chambers. There are two upper chambers, called atria.2
- Count the lower chambers. There are two lower chambers, called ventricles. 2 + 2 is the total.2 + 2 = 4
- Write the answer. 4
Check. The heart has four chambers in total. ✓
Method. Follow the loop from the heart.
- Start at the heart. The heart sends blood to the lungs to pick up oxygen.lungs
- Name the organ. So the first organ the blood goes to is the lungs.lungs
- Write the answer. lungs
Check. The blood returns to the heart after the lungs. ✓
Method. Find the chambers that pump.
- Read the key. The ventricles are the two lower chambers, and they pump blood out.ventricles
- Write the answer. So the chambers that pump blood out are the ventricles.ventricles
- Write the answer. ventricles
Check. The atria receive blood; the ventricles pump it out. ✓
Watch out
Watch out: the heart does not pump blood through the body only. Blood first goes to the lungs to pick up oxygen, and then it is pumped to the body.
Exam tip
Exam tip. Name the four chambers correctly: two atria receive blood, and two ventricles pump blood out.
Try it (with your teacher, or a grown-up at home). Put two fingers on the side of your neck or the inside of your wrist, with a grown-up. Feel the beat of your pulse. Count the beats for 15 seconds, then stop. Ask a grown-up to remind you that your heart is a muscle that works harder when you move.
Exercise 3A The heart as a pump
Method. Think about the muscle that pushes blood.
- Recall the organ. The heart is a muscular pump that moves blood.heart
- Write the answer. heart
Check. The heart is in the middle of the chest. ✓
Method. Count the chambers.
- Count. The heart has two upper chambers and two lower chambers.2 + 2
- Total. So the heart has four chambers.4
- Write the answer. 4
Check. Two atria and two ventricles. ✓
Method. Read the description of the chambers.
- Read the description. The two upper chambers receive blood. They are called atria.atria
- Write the answer. atria
Check. Atrium is the singular word for one upper chamber. ✓
Method. Read the description of the chambers.
- Read the description. The two lower chambers pump blood out. They are called ventricles.ventricles
- Write the answer. ventricles
Check. The ventricles are the pumping chambers. ✓
Method. Read the loop diagram.
- Follow the arrow. The arrow from the heart goes to the lungs.lungs
- Write the answer. lungs
Check. The blood then returns to the heart. ✓
Method. Read the arrows in the loop diagram.
- Read the arrow. The blue arrow from the heart to the lungs is oxygen-poor blood.oxygen-poor
- Write the answer. oxygen-poor
Check. The blood picks up oxygen in the lungs. ✓
Method. Think about where the blood has come from.
- Follow the loop. The blood has just come from the lungs, where it picked up oxygen.from the lungs
- Write the answer. So it is oxygen-rich blood going to the body.oxygen-rich
- Write the answer. oxygen-rich
Check. Oxygen-rich blood is sent to the body. ✓
Method. Check the number of chambers.
- Check. The heart has two upper and two lower chambers.4 chambers
- Decide. So Ali is not right; the heart has four chambers.no
- Write the answer. no
Check. Two chambers is only half of the total. ✓
Method. Use the key of the heart.
- Find the pumping chambers. The ventricles are the two lower chambers that pump blood out.ventricles
- Count. There are two ventricles.2
- Write the answer. 2
Check. The atria receive the blood, and the ventricles pump it out. ✓
Method. Follow the loop.
- Find the first place. The loop starts at the heart, then goes to the lungs.lungs
- Write the answer. So the first place is the lungs.lungs
- Write the answer. lungs
Check. The loop then returns the blood to the heart. ✓
Method. Think about what a pump does.
- Think about the muscle. The heart is a muscle that squeezes.muscle
- Think about the blood. Squeezing pushes blood through the vessels around the body.pushes blood
- Write the answer. Accept any sentence that says the heart is a muscle that squeezes blood into the vessels, pushing it around the body.
Check. A pump moves a liquid by pushing it. ✓
Method. Think about what the blood needs.
- Think about the blood. The blood coming back from the body has used up oxygen.used up oxygen
- Think about the lungs. The lungs give the blood more oxygen before it goes round the body again.more oxygen
- Write the answer. Accept any sentence that says the blood must pick up oxygen from the lungs before it can be sent round the body again.
Check. The loop keeps the blood supplied with oxygen. ✓
Method. Think about what blood carries.
- Think about the blood. Blood carries oxygen and nutrients.oxygen and nutrients
- Think about the heart. The heart keeps the blood moving to every part of the body.every part
- Write the answer. Accept any sentence that says the heart keeps blood moving, so that oxygen and nutrients reach every part of the body.
Check. If the heart stops, the blood stops moving. ✓