Your heart is a pump. Its job is to push blood through tubes (blood vessels) to every part of your body. The blood carries oxygen from your lungs and nutrients from your food to all of your cells. Without the heart pumping, blood would not flow and your body could not work.
Question 2 True / False
Your heart stops beating when you fall asleep.
TTrue
FFalse
Answer: False
Your heart never stops beating — not even for a second. When you sleep, your heart slows down a little because your body does not need as much blood flow, but it keeps pumping all night long. It beats about 100,000 times every day, awake and asleep.
Question 3 Short Answer
Why does your heart beat faster when you run or jump?
Think about your answer, then reveal below.
Model answer: When you exercise, your muscles need more oxygen and energy to keep moving. Your heart beats faster to pump more blood to those muscles, delivering the extra oxygen and nutrients they need.
Exercise increases the demand on your muscles. More demand means more oxygen and fuel are needed. The heart responds by beating faster and harder, pushing more blood per minute. This is why you can feel your heart pounding after running — it is working overtime to supply your muscles.