Biology Homework Help! Need Criticism!

You are walking down the street one day, whistling to yourself. You kick a can into the gutter. Suddenly, somebody calls out to you, “Hey Jane! Come play some footie with us!” You whisk round and spot several of the other girls playing in the park. You run towards them. You superbly tackle the ball and shoot it into the back of the net. After you have played for a while, your heat rate has started to get faster and faster. You start to breath rapidly. You didn’t bring a drink with you, and none of the other girls will give your theirs’. You have to go and sit in the shade for a while.
While you are sitting on a bench, a nerdy looking boy walks over to you. He sits down next to you. “What’s up with you? You’re always playing football, are you tired or something?” He asks you. You tell him how long you have been playing, and that you don’t have a drink. He hands you a bottle of Coke. “Thanks.” You mutter. “Do you know why you’re tired? I do.” Said the boy. “Go on then.” You say, “Tell me.”
“Well, it’s all to do with blood,” You shudder at the thought, “When you breath, the oxygen goes in your Mouth, down your Oesophagus, and into your Trachea.” the boy says. You‘re puzzled. “What’s a Trachea and an Oesophagus?” You ask. “Your Oesophagus is basically your throat, and your Trachea is your windpipe. Anyway, when the oxygen has passed through the Trachea it goes to the Bronchi, which are in your lungs. There are two of them, and they look a bit like this…” He opens his phone and starts to look through his files. “Aha, here it is..”





Picture goes here =P




You look at it. It all looks like random lines to you, or an upside down tree. He flips his phone closed and puts it away. “Those little branches are called Bronchioles, and on the ends of them are Alveoli. They are like little air sacs and when you breath they inflate! They have little Capillaries running all over them, and there are loads, so together they have a huge surface area! Wicked hey!” the boy laughs. You nod, not really understanding. You never were very bright, especially when it came to Science.
“Capillaries, the key to respiration!” He says. “Um, what are Capillaries?” you ask him nervously. “Ha! Capillaries are teeny tiny little veins and they carry blood,” You shudder again, “All over the body. They have walls only one cell thick and that means that when they get to the Alveoli, they can exchange gases through the walls! Genius, pure genius! So, when the blood comes back into the capillaries and past the Alveoli, they then exchange Carbon Dioxide. So when the blood first comes round, it gets oxygen, then it comes back with C02 and gets more oxygen and so on. Great eh?”