Question

Which of the following most likely happens when we exercise?

A. The heart rate slows down because the blood vessels have less blood to circulate.

B.The heart rate slows down because the blood vessels have more blood to circulate.

C. The heart pumps faster so that the blood vessels can carry more oxygen to some cells.

D.The heart pumps faster so that the blood vessels can carry more carbon dioxide to some cells.

Answer 1

I think C because to not get lightheaded, you need blood to go to your brain and if you're exercising and you feel light headed or dizzy, you wouldn't be able to exercise!. So from my understanding, the answer would be C but I am not 100% Hope this helps! :)

Answer 2

When you exercise, you use more oxygen to fuel your cells, so your body can function at a faster pace. Oxygen is what your cells need, carbon dioxide isn't. Carbon dioxide is a waste we breathe out through the respiratory process. 

To pump more blood to the body, the heart would need to pump faster.

So, the best answer is "C". We need oxygen, and your heart rate pumps faster.

I hope this helps!
~kaikers