“Hello class”. “Hello Mrs. Molecule” moaned the class. “Today we are going on a fieldtrip” sang Mrs. Molecule. “I will explain the rest on the way”. We surfed the breeze, shocked and confused. Why were we here? Suddenly we came to a stop. “Well class today is your day to shine. We are going inside a human” Wow! This was the day. I stared blankly into space. If I pass this then I can graduate school and go on to bigger things. We floated over to a pack of people talking and texting on their phones. Everyone was dead silent. We all knew exactly what to do. Hands linked, we all relaxed and braced ourselves for the beginning of our journey.

We jolted forward into what I believe was the nasal cavity. I knew this because I could spot a little mucus and cilia. Caught in the mucus was a small piece of pollen, trapped and hopeless. I studied the walls of this unknown place. Where were we? I glanced around to make sure that I was not the only one to look clueless. Thankfully, I could see the rest of the class was hopelessly lost. “Ok class, this is the pharynx. This is where the mouth and the nasal cavity meet together to make one tube.” We all glanced around still clueless. “Quick, follow me.” We dashed under what looked like a flab of skin. I could hear the sound of water sloshing down above us. “What was that?” I questioned. “That sloshing sound was the sound of flowing water. That flap right there is called the epiglottis, it prevents food from coming down the windpipe. Now let’s continue down the larynx.” I stared ahead looking at the vocal cords. Everything that I had learned seemed to be coming together right now. It was very crowded in here. Many other molecules were zooming past us. As they did the vocal cords vibrated with rage. The vocal cords tightened causing a high pitched sound to roar out of the boys mouth. We dashed through the vocal cords and found ourselves in the trachea. Déjà vu! We were in a tube lined with mucus and cilia. We soared down the trachea for what seemed like forever. We ended at the bronchi. “We can no longer travel in a group. You are now on your own” she explained. “But what if we get lost?” exclaimed one of my classmates. “You won’t. There are many friendly red blood cells here.” And then we were off. This was it. If I do this right, I can be the first one to graduate. So I was off, confident but alone. Well, maybe not alone. I was surrounded by other oxygen molecules, but they were strangers. I followed a speeding stranger. I trusted that because he was going so fast, he knew exactly what he was doing. We sped down the bronchioles and into what I believe was the alveoli. Suddenly, this stranger stopped and looked back. He kept his eyes on me. “Yes?” I asked. “Are you following me?” he questioned. “I’m sorry. I am a little lost”. “That’s ok. I can help you.” “Wow! Thank you, mister. So where are we?” “We are in the alveoli. Just follow me and keep up.” He dashed away into what looked like a little room. A line was formed in front of a wall. My eyes traced the wall and then landed on the next person in line. Were my eyes deceiving me? I fluttered my eyes. “What happened to that molecule?”. “He just defused through that wall”. “Oh, don’t worry you will understand it when it is your turn”. I watched the wall as carbon dioxide molecules defused towards us and raced out the bronchioles. “Just watch”. And just like that he was gone. I took one last breath and hoped for the best. Before I knew what was happening I was riding a red blood cell. “This is the pulmonary vein. It will take us to the heart.” Right then and there I felt powerful. I was going to the heart. The one thing that keeps this human alive. Now what was that song? (I learned the heart song in 4th grade) “Left A-t-r-i-u-m Left A-t-r-i-u-m Left V-e-n-t-r-i-c-l-e Left V-e-n-t-r-i-c-l-e Aorta! Aorta! Down Down Down!” I sang my song as I passed through each off the parts. As we left the aorta we transitioned into the Femoral artery. The Femoral artery brings oxygen to the cells in the legs. We stayed in the Femoral artery for quite a while and then transferred into smaller and smaller arteries called capillaries.

“Ahhh!” I was bucked off my blood cell and was forced to defuse into a cell. “Where were we?” My eyes wandered around the cell and soon spotted a line of people. “Excuse me. Where are we?” “This is it the end of our journey, we are to be used by the mitochondria for energy.” “This is where it ends?”. “Yup after this your services are no longer needed”

Look at me I had come all this way and I was ready. I was ready for anything really. One thought raced in my head. “Look at how far I had come.” My main purpose was on its way and all I did was stop and think. Stop and think about all that I have done.