I will answer only the first section of the Oxygen path. I believe you will be able to look up the rest of the path on your own. *Good Luck*
First air enters your nose which includes oxygen. The nose contains hairs because when you breathe in dust particles also enters your nose and your nose hairs stops the particles from entering your body. Next Oxygen enters your windpipe (aka large trachea) which is the tube that leads to your lungs. The lungs are a large pair or organs that are located in the human's chest. The lungs are very important organs because without this oxygen could have never entered our bodies to perform the process of respiration. Next is the Bronchi. The Bronchi are large tubes that are located in our lungs. When Oxygen enters our lungs Oxygen goes into our Bronchi which then results in the Bronchi to expand. After the Oxygen goes through the Bronchi it gets divided and moves into smaller tubes called bronchioles. There is an estimate of 30,000 bronchioles in each lung. Air from the Bronchioles then goes into the alveoli which are tiny air sacks. There the Oxygen is separated from the rest of the air inside and it moves into the capillaries. Here is where the Oxygen goes into the blood and Carbon Dioxide comes in from the blood to the lungs.