What’s Inside My Body: Red Blood Cells

It was the weekend, and Charlotte went on a trip to the mountains with her parents. They set out along a forest trail marked with blue signs. The journey was going smoothly. As usual, Charlotte ran a few steps ahead of her parents. Her dad was responsible for keeping them on the right trail, while her mum pointed out the different plants and foliage.

“Charlotte, did you know that all green plants produce oxygen, which we humans actually need in order to breathe?” her mum asked, before continuing. “In turn, the plants need carbon dioxide, which we humans exhale with each breath. Plants are therefore very important to us — without them, we wouldn’t be living on this planet at all.”

As they advanced along the path, the landscape changed. There were no longer any trees, and green leaves were replaced by thick moss. Also, the trail became more and more rocky. Charlotte was still in front, but as they started up the mountain the path became very steep, which slowed her down. Everyone could barely catch their breath.

When they reached the top, Charlotte was overjoyed. Not only was the difficult climb finally over, but the view was truly beautiful. They could see the nearby town and the hills beyond. The cool wind whistled in their ears as they made their way back down the narrow, rocky slope. Charlotte was happily singing and skipping alongside her mother, but she wasn’t paying close attention to the ground under her feet. Suddenly she tripped over a jagged stone.

Her mum bent down and gave her a hug, while her dad inspected the knee. “It looks like a nasty scrape, Charlotte — your knee hit against a sharp rock, that’s why it’s bleeding.”

Charlotte peeked at…