Heart and blood quiz
Checked on 12 November 2026
Question 1 of 10
Discover
Which blood vessels carry blood away from the heart?
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The answer is Arteries.
Arteries carry blood away from the heart, while veins bring it back.
Discover
Which blood cells carry oxygen around the body?
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The answer is Red blood cells.
Red blood cells are the most common blood cells, and they deliver oxygen to the body's tissues.
Discover
What are the smallest blood vessels in the body called?
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The answer is Capillaries.
Capillaries are the smallest and most numerous blood vessels, linking the arteries to the veins.
Discover
Which spongy tissue inside some bones makes new blood cells?
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The answer is Bone marrow.
Bone marrow, found inside bones such as the hip and thigh, makes red cells, white cells and platelets.
Practise
What is the name of the heart's natural pacemaker?
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The answer is Sinoatrial (SA) node.
Each heartbeat starts with an electrical signal from pacemaker cells in the SA node, in the right atrium.
Practise
Which tiny parts of the blood help it clot after a cut?
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The answer is Platelets.
Platelets are tiny cell fragments that clump together to plug a damaged blood vessel and form a clot.
Practise
What is the liquid part of blood, making up about 55% of it, called?
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The answer is Plasma.
Plasma is the pale liquid part of blood that carries the red cells, white cells and platelets.
Expert
Which heart valve sits between the right atrium and the right ventricle?
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The answer is Tricuspid valve.
The tricuspid valve lets blood flow from the right atrium into the right ventricle and stops it flowing back.
Expert
Which English physician described the circulation of the blood in a book published in 1628?
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The answer is William Harvey.
William Harvey published De Motu Cordis in 1628, showing how the heart pumps blood around the body.
Expert
People with which blood type are often called universal donors for red blood cells?
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The answer is O negative.
Type O negative red cells can be given to patients of every blood type, which is why these donors are so valued.