Know Your Body
Cardiovascular System
Heart, blood, and blood vessels
Official source located — human medical review required.
How it works
Your cardiovascular system is made of your heart, blood, and blood vessels. Your heart is a muscle that works like a pump. It normally beats 60 to 100 times every minute, all day and night. Blood vessels called arteries carry blood away from your heart, and veins carry blood back to it. Your heart pumps blood so it can travel around your whole body, delivering oxygen and nutrients to your cells.
Official source located — human medical review required.
Explore three questions
Select a card to open its answer. Select it again to close.
Three key learning points
- The heart is a muscle that pumps blood around your body.
- Blood carries oxygen and other important substances to your cells and organs.
- Arteries carry blood away from the heart; veins carry it back.
Official source located — human medical review required.
Five-question quiz
One question at a time, with feedback after each answer. There is no pass or fail here.
Question 1 of 5
All official sources for this lesson
Official source located — human medical review required.
Medical-review checklist for this system
- Confirm the heart-rate range (60–100 bpm) is presented as a general resting range, not a diagnostic threshold
- Confirm "artery/vein" direction language is accurate and not oversimplified in a misleading way
- Confirm no wording implies this content can assess a real heart condition